810 PART 178SPECIFICATIONS FOR PACKAGINGS

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					                                                                    Pt. 178                                                               49 CFR Ch. I (10–1–09 Edition)

                                                                    war of the Departments of the Army,                       sion 2.3 (poisonous gas) material, or
                                                                    Navy, and Air Force of the United                         any paranitroaniline, in any amount,
                                                                    States Government, are authorized by                      in or on any bus while engaged in the
                                                                    parts 170–189 of this subchapter to be                    transportation of passengers; or any
                                                                    transported on motor vehicles carrying                    less dangerous Division 6.1 (poisonous)
                                                                    passengers for hire where other prac-                     material, which is other than a liquid,
                                                                    ticable means of transportation is                        in any amount exceeding an aggregate
                                                                    available.                                                of 45 kg (99 pounds) gross weight in or
                                                                      (c) Class 1 (explosive) materials in pas-               on any such bus.
                                                                    senger-carrying space forbidden. No Class                   (g) Class 7 (radioactive) materials. In
                                                                    1 (explosive) material, except small-                     addition to the limitations prescribed
                                                                    arms ammunition, may be carried in                        in paragraphs (b) and (e) of this sec-
                                                                    the passenger-carrying space of any                       tion, no person may transport any
                                                                    motor vehicle transporting passengers                     Class 7 (radioactive) material requiring
                                                                    for hire.                                                 labels under §§ 172.436, 172.438, and
                                                                      (d) Hazardous materials on passenger                    172.440 of this subchapter in or on any
                                                                    carrying vehicles; quantity. Where no                     motor vehicle carrying passengers for
                                                                    other practicable means of transpor-                      hire except where no other practicable
                                                                    tation is available the following arti-                   means of transportation is available.
                                                                    cles in the quantities as shown may be                    Packages of Class 7 (radioactive) mate-
                                                                    transported in motor vehicles carrying                    rials must be stored only in the trunk
                                                                    passengers for hire in a space other                      or baggage compartment of the vehi-
                                                                    than that provided for passengers: Not                    cle, and must not be stored in any com-
                                                                    to exceed 45 kg (99 pounds) gross                         partment occupied by persons. Pack-
                                                                    weight of any or all of the kinds of                      ages of Class 7 (radioactive) materials
                                                                    Class 1 (explosive) materials permitted                   must be handled and placed in the vehi-
                                                                    to be transported by passenger-car-                       cle as prescribed in § 177.842.
                                                                    rying aircraft or rail car may be trans-                  [29 FR 18795, Dec. 29, 1964. Redesignated at 32
                                                                    ported on a motor vehicle transporting                    FR 5606, Apr. 5, 1967]
                                                                    passengers: Provided, however, That
                                                                    samples of Class 1 (explosive) materials                    EDITORIAL NOTE: For FEDERAL REGISTER ci-
                                                                                                                              tations affecting § 177.870 see the List of CFR
                                                                    for laboratory examination, not to ex-
                                                                                                                              Sections Affected which appears in the Find-
                                                                    ceed two samples, or a total of no more                   ing Aids section of the printed volume and
                                                                    than 100 detonators, Division 1.4 (explo-                 on GPO Access.
                                                                    sive) materials at one time in a single
                                                                    motor vehicle, may be transported in a                      PART 178—SPECIFICATIONS FOR
                                                                    motor vehicle transporting passengers.
                                                                      (e) Articles other than Class 1 (explo-                           PACKAGINGS
                                                                    sive) materials on passenger-carrying ve-
                                                                                                                              Sec.
                                                                    hicles. The gross weight of any given
                                                                                                                              178.1   Purpose and scope.
                                                                    class of hazardous material other than                    178.2   Applicability and responsibility.
                                                                    Class 1 (explosive) materials shall not                   178.3   Marking of packagings.
                                                                    exceed 45 kg (99 pounds), and the aggre-
                                                                    gate weight of all such other dangerous                                Subpart A [Reserved]
                                                                    articles shall not exceed 225 kg (496
                                                                    pounds). This provision does not apply                        Subpart B—Specifications for Inside
                                                                    to nontoxic, nonflammable refrig-                                  Containers, and Linings
                                                                    erants, when such refrigerant is for                      178.33 Specification 2P; inner nonrefillable
                                                                    servicing operations of a motor carrier                       metal receptacles.
                                                                    on whose motor vehicles the refrig-                       178.33–1 Compliance.
                                                                    erant is used. A cylinder secured                         178.33–2 Type and size.
                                                                    against shifting while in transit and                     178.33–3 Inspection.
                                                                    not exceeding 113 kg (250 pounds) gross                   178.33–4 Duties of inspector.
                                                                    weight may be transported.                                178.33–5 Material.
                                                                                                                              178.33–6 Manufacture.
                                                                      (f) Division 6.1 (poisonous) or Division
                                                                                                                              178.33–7 Wall thickness.
                                                                    2.3 (poisonous gas) materials on pas-                     178.33–8 Tests.
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                                                                    senger-carrying vehicles. No motor car-                   178.33–9 Marking.
                                                                    rier may transport any extremely dan-                     178.33a Specification 2Q; inner nonrefillable
                                                                    gerous Division 6.1 (poisonous) or Divi-                      metal receptacles.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 Pt. 178
                                                                    178.33a–1 Compliance.                                     178.68 Specification 4E welded aluminum
                                                                    178.33a–2 Type and size.                                      cylinders.
                                                                    178.33a–3 Inspection.                                     178.69 Responsibilities and requirements for
                                                                    178.33a–4 Duties of inspector.                                manufacturers of UN pressure recep-
                                                                    178.33a–5 Material.                                           tacles.
                                                                    178.33a–6 Manufacture.                                    178.70 Approval of UN pressure receptacles.
                                                                    178.33a–7 Wall thickness.                                 178.71 Specifications for UN pressure recep-
                                                                    178.33a–8 Tests.                                              tacles.
                                                                    178.33a–9 Marking.                                        178.74 Approval of MEGCs.
                                                                    178.33b Specification 2S; inner nonrefillable             178.75 Specifications for MEGCs.
                                                                        plastic receptacles [Reserved]                        APPENDIX A TO SUBPART C—ILLUSTRATIONS:
                                                                    178.33b–1 Compliance.                                         CYLINDER TENSILE SAMPLE
                                                                    178.33b–2 Type and size.
                                                                    178.33b–3 Inspection.                                                 Subparts D–G [Reserved]
                                                                    178.33b–4 Duties of inspector.
                                                                    178.33b–5 Material.                                         Subpart H—Specifications for Portable
                                                                    178.33b–6 Manufacture.                                                    Tanks
                                                                    178.33b–7 Design Qualification Test.
                                                                    178.33b–8 Production Tests.                               178.251—178.253–5 [Reserved]
                                                                    178.33b–9 Marking.                                        178.255 Specification 60; steel portable
                                                                                                                                  tanks.
                                                                      Subpart C—Specifications for Cylinders                  178.255–1 General requirements.
                                                                                                                              178.255–2 Material.
                                                                    178.35 General requirements for specifica-                178.255–3 Expansion domes.
                                                                        tion cylinders.                                       178.255–4 Closures for manholes and domes.
                                                                    178.36 Specification 3A and 3AX seamless                  178.255–5 Bottom discharge outlets.
                                                                        steel cylinders.                                      178.255–6 Loading and unloading accessories.
                                                                    178.37 Specification 3AA and 3AAX seamless                178.255–7 Protection of valves and acces-
                                                                        steel cylinders.                                          sories.
                                                                    178.38 Specification 3B seamless steel cyl-               178.255–8 Safety devices.
                                                                        inders.                                               178.255–9 Compartments.
                                                                    178.39 Specification 3BN seamless nickel                  178.255–10 Lining.
                                                                        cylinders.                                            178.255–11 Tank mountings.
                                                                    178.42 Specification 3E seamless steel cyl-               178.255–12 Pressure test.
                                                                        inders.                                               178.255–13 Repair of tanks.
                                                                    178.44 Specification 3HT seamless steel cyl-              178.255–14 Marking.
                                                                        inders for aircraft use.                              178.255–15 Report.
                                                                    178.45 Specification 3T seamless steel cyl-               178.273 Approval of Specification UN port-
                                                                        inders.                                                   able tanks.
                                                                    178.46 Specification 3AL seamless alu-                    178.274 Specification for UN portable tanks.
                                                                        minum cylinders.                                      178.275 Specification for UN Portable Tanks
                                                                    178.47 Specification 4DS welded stainless                     intended for the transportation of liquid
                                                                        steel cylinders for aircraft use.                         and solid hazardous materials.
                                                                    178.50 Specification 4B welded or brazed                  178.276 Requirements for the design, con-
                                                                        steel cylinders.                                          struction, inspection and testing of port-
                                                                    178.51 Specification 4BA welded or brazed                     able tanks intended for the transpor-
                                                                        steel cylinders.                                          tation of non-refrigerated liquefied com-
                                                                    178.53 Specification 4D welded steel cyl-                     pressed gases.
                                                                        inders for aircraft use.                              178.277 Requirements for the design, con-
                                                                    178.55 Specification 4B240ET welded or                        struction, inspection and testing of port-
                                                                        brazed cylinders.                                         able tanks intended for the transpor-
                                                                    178.56 Specification 4AA480 welded steel cyl-                 tation of refrigerated liquefied gases.
                                                                        inders.
                                                                    178.57 Specification 4L welded insulated cyl-                           Subpart I [Reserved]
                                                                        inders.
                                                                    178.58 Specification 4DA welded steel cyl-                Subpart J—Specifications for Containers for
                                                                        inders for aircraft use.                                    Motor Vehicle Transportation
                                                                    178.59 Specification 8 steel cylinders with
                                                                        porous fillings for acetylene.                        178.318 Specification MC 201; container for
                                                                    178.60 Specification 8AL steel cylinders                      detonators and percussion caps.
                                                                        with porous fillings for acetylene.                   178.318–1 Scope.
                                                                    178.61 Specification 4BW welded steel cyl-                178.318–2 Container.
                                                                        inders with electric-arc welded longitu-              178.318–3 Marking.
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                                                                        dinal seam.                                           178.320 General requirements applicable to
                                                                    178.65 Specification 39 non-reusable (non-re-                 all DOT specification cargo tank motor
                                                                        fillable) cylinders.                                      vehicles.

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                                                                    Pt. 178                                                                 49 CFR Ch. I (10–1–09 Edition)
                                                                    178.337 Specification MC 331; cargo tank                  178.345–15 Certification.
                                                                        motor vehicle primarily for transpor-                 178.346 Specification DOT 406; cargo tank
                                                                        tation of compressed gases as defined in                  motor vehicle.
                                                                        subpart G of part 173 of this subchapter.             178.346–1 General requirements.
                                                                    178.337–1 General requirements.                           178.346–2 Material and thickness of mate-
                                                                    178.337–2 Material.                                           rial.
                                                                    178.337–3 Structural integrity.                           178.346–3 Pressure relief.
                                                                    178.337–4 Joints.                                         178.346–4 Outlets.
                                                                    178.337–5 Bulkheads, baffles and ring stiff-              178.346–5 Pressure and leakage tests.
                                                                        eners.                                                178.347 Specification DOT 407; cargo tank
                                                                    178.337–6 Closure for manhole.                                motor vehicle.
                                                                    178.337–7 Overturn protection.                            178.347–1 General requirements.
                                                                    178.337–8 Openings, inlets and outlets.                   178.347–2 Material and thickness of mate-
                                                                    178.337–9 Pressure relief devices, piping,                    rial.
                                                                        valves, hoses, and fittings.                          178.347–3 Manhole assemblies.
                                                                    178.337–10 Accident damage protection.                    178.347–4 Pressure relief.
                                                                    178.337–11 Emergency discharge control.                   178.347–5 Pressure and leakage test.
                                                                    178.337–12 [Reserved]                                     178.348 Specification DOT 412; cargo tank
                                                                    178.337–13 Supporting and anchoring.                          motor vehicle.
                                                                    178.337–14 Gauging devices.                               178.348–1 General requirements.
                                                                    178.337–15 Pumps and compressors.                         178.348–2 Material and thickness of mate-
                                                                    178.337–16 Testing.                                           rial.
                                                                    178.337–17 Marking.                                       178.348–3 Pumps, piping, hoses and connec-
                                                                    178.337–18 Certification.                                     tions.
                                                                    178.338 Specification      MC–338;     insulated          178.348–4 Pressure relief.
                                                                        cargo tank motor vehicle.                             178.348–5 Pressure and leakage test.
                                                                    178.338–1 General requirements.
                                                                    178.338–2 Material.                                        Subpart K—Specifications for Packagings
                                                                    178.338–3 Structural integrity.                               for Class 7 (Radioactive) Materials
                                                                    178.338–4 Joints.
                                                                    178.338–5 Stiffening rings.                               178.350 Specification 7A; general packaging,
                                                                    178.338–6 Manholes.                                           Type A.
                                                                    178.338–7 Openings.                                       178.356 Specification 20PF phenolic-foam in-
                                                                    178.338–8 Pressure relief devices, piping,                    sulated, metal overpack.
                                                                        valves, and fittings.                                 178.356–1 General requirements.
                                                                    178.338–9 Holding time.                                   178.356–2 Materials of construction and
                                                                    178.338–10 Accident damage protection.                        other requirements.
                                                                    178.338–11 Discharge control devices.                     178.356–3 Tests.
                                                                    178.338–12 Shear section.                                 178.356–4 Required markings.
                                                                    178.338–13 Supporting and anchoring.                      178.356–5 Typical assembly detail.
                                                                    178.338–14 Gauging devices.                               178.358 Specification 21PF fire and shock re-
                                                                    178.338–15 Cleanliness.                                       sistant, phenolic-foam insulated, metal
                                                                    178.338–16 Inspection and testing.                            overpack.
                                                                    178.338–17 Pumps and compressors.                         178.358–1 General requirements.
                                                                    178.338–18 Marking.                                       178.358–2 Materials of construction and
                                                                    178.338–19 Certification.                                     other requirements.
                                                                    178.340–178.343 [Reserved]                                178.358–3 Modification     of   Specification
                                                                    178.345 General design and construction re-                   21PF–1 overpacks.
                                                                        quirements applicable to Specification                178.358–4 Construction     of   Specification
                                                                        DOT 406 (§ 178.346), DOT 407 (§ 178.347), and             21PF–1B overpacks.
                                                                        DOT 412 (§ 178.348) cargo tank motor vehi-            178.358–5 Required markings.
                                                                        cles.                                                 178.358–6 Typical assembly detail.
                                                                    178.345–1 General requirements.                           178.360 Specification 2R; inside containment
                                                                    178.345–2 Material and material thickness.                    vessel.
                                                                    178.345–3 Structural integrity.                           178.360–1 General requirements.
                                                                    178.345–4 Joints.                                         178.360–2 Manufacture.
                                                                    178.345–5 Manhole assemblies.                             178.360–3 Dimensions.
                                                                    178.345–6 Supports and anchoring.                         178.360–4 Closure devices.
                                                                    178.345–7 Circumferential reinforcements.
                                                                    178.345–8 Accident damage protection.                         Subpart L—Non-bulk Performance-
                                                                    178.345–9 Pumps, piping, hoses and connec-                      Oriented Packaging Standards
                                                                        tions.
                                                                    178.345–10 Pressure relief.                               178.500     Purpose, scope and definitions.
                                                                    178.345–11 Tank outlets.                                  178.502     Identification codes for packagings.
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                                                                    178.345–12 Gauging devices.                               178.503     Marking of packagings.
                                                                    178.345–13 Pressure and leakage tests.                    178.504     Standards for steel drums.
                                                                    178.345–14 Marking.                                       178.505     Standards for aluminum drums.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.2
                                                                    178.506 Standards for metal drums other                   178.811 Bottom lift test.
                                                                        than steel or aluminum.                               178.812 Top lift test.
                                                                    178.507 Standards for plywood drums.                      178.813 Leakproofness test.
                                                                    178.508 Standards for fiber drums.                        178.814 Hydrostatic pressure test.
                                                                    178.509 Standards for plastic drums and                   178.815 Stacking test.
                                                                        jerricans.                                            178.816 Topple test.
                                                                    178.510 Standards for wooden barrels.                     178.817 Righting test.
                                                                    178.511 Standards for aluminum and steel                  178.818 Tear test.
                                                                        jerricans.                                            178.819 Vibration test.
                                                                    178.512 Standards for steel or aluminum                   APPENDIX A TO PART 178—SPECIFICATIONS FOR
                                                                        boxes.                                                    STEEL
                                                                    178.513 Standards for boxes of natural wood.              APPENDIX B TO PART 178—ALTERNATIVE
                                                                    178.514 Standards for plywood boxes.                          LEAKPROOFNESS TEST METHODS
                                                                    178.515 Standards for reconstituted wood                  APPENDIX C TO PART 178—NOMINAL AND MIN-
                                                                        boxes.                                                    IMUM THICKNESSES OF STEEL DRUMS AND
                                                                    178.516 Standards for fiberboard boxes.                       JERRICANS
                                                                    178.517 Standards for plastic boxes.                      APPENDIX D TO PART 178—THERMAL RESIST-
                                                                    178.518 Standards for woven plastic bags.                     ANCE TEST
                                                                    178.519 Standards for plastic film bags.                  APPENDIX E TO PART 178—FLAME PENETRA-
                                                                    178.520 Standards for textile bags.                           TION RESISTANCE TEST
                                                                    178.521 Standards for paper bags.
                                                                                                                                AUTHORITY: 49 U.S.C. 5101–5128; 49 CFR 1.53.
                                                                    178.522 Standards for composite packagings
                                                                        with inner plastic receptacles.                       § 178.1 Purpose and scope.
                                                                    178.523 Standards for composite packagings
                                                                        with inner glass, porcelain, or stoneware                This part prescribes the manufac-
                                                                        receptacles.                                          turing and testing specifications for
                                                                                                                              packaging and containers used for the
                                                                           Subpart M—Testing of Non-bulk                      transportation of hazardous materials
                                                                             Packagings and Packages                          in commerce.
                                                                    178.600 Purpose and scope.                                [Amdt. 178–40, 42 FR 2689, Jan. 13, 1977. Redes-
                                                                    178.601 General requirements.                             ignated by Amdt. 178–97, 55 FR 52715, Dec. 21,
                                                                    178.602 Preparation of packagings and pack-               1990]
                                                                        ages for testing.
                                                                    178.603 Drop test.                                        § 178.2 Applicability      and    responsi-
                                                                    178.604 Leakproofness test.                                     bility.
                                                                    178.605 Hydrostatic pressure test.
                                                                                                                                 (a) Applicability. (1) The requirements
                                                                    178.606 Stacking test.
                                                                    178.607 Cooperage test for bung-type wooden               of this part apply to packagings manu-
                                                                        barrels.                                              factured—
                                                                    178.608 Vibration standard.                                  (i) To a DOT specification, regardless
                                                                    178.609 Test requirements for packagings for              of country of manufacture; or
                                                                        infectious substances.                                   (ii) To a UN standard, for packagings
                                                                                                                              manufactured        within    the   United
                                                                      Subpart N—IBC Performance-Oriented                      States. For UN standard packagings
                                                                                   Standards                                  manufactured outside the United
                                                                    178.700 Purpose, scope and definitions.                   States, see § 173.24(d)(2) of this sub-
                                                                    178.702 IBC codes.                                        chapter. For UN standard packagings
                                                                    178.703 Marking of IBCs.                                  for which standards are not prescribed
                                                                    178.704 General IBC standards.                            in this part, see § 178.3(b).
                                                                    178.705 Standards for metal IBCs.                            (2) A manufacturer of a packaging
                                                                    178.706 Standards for rigid plastic IBCs.                 subject to the requirements of this part
                                                                    178.707 Standards for composite IBCs.                     is primarily responsible for compliance
                                                                    178.708 Standards for fiberboard IBCs.
                                                                    178.709 Standards for wooden IBCs.
                                                                                                                              with the requirements of this part.
                                                                    178.710 Standards for flexible intermediate               However, any person who performs a
                                                                        bulk containers.                                      function prescribed in this part shall
                                                                                                                              perform that function in accordance
                                                                               Subpart O—Testing of IBCs                      with this part.
                                                                                                                                 (b) Specification markings. When this
                                                                    178.800 Purpose and scope.
                                                                                                                              part requires that a packaging be
                                                                    178.801 General requirements.
                                                                    178.802 Preparation of fiberboard IBCs for                marked with a DOT specification or UN
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                                                                        testing.                                              standard marking, marking of the
                                                                    178.803 Testing and certification of IBCs.                packaging with the appropriate DOT or
                                                                    178.810 Drop test.                                        UN markings is the certification that—

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                                                                    § 178.3                                                               49 CFR Ch. I (10–1–09 Edition)

                                                                      (1) Except as otherwise provided in                     part of the specification markings re-
                                                                    this section, all requirements of the                     quired by this part or, for a packaging
                                                                    DOT specification or UN standard, in-                     marked with the symbol of an approval
                                                                    cluding performance tests, are met;                       agency, the person on whose behalf the
                                                                    and                                                       approval agency certifies the pack-
                                                                      (2) All functions performed by, or on                   aging.
                                                                    behalf of, the person whose name or                         Specification markings mean the pack-
                                                                    symbol appears as part of the marking                     aging identification markings required
                                                                    conform to requirements specified in                      by this part including, where applica-
                                                                    this part.                                                ble, the name and address or symbol of
                                                                      (c) Notification. Except as specifically                the packaging manufacturer or ap-
                                                                    provided in §§ 178.337–18 and 178.345–10 of               proval agency.
                                                                    this part, the manufacturer or other                        (f) No packaging may be manufac-
                                                                    person certifying compliance with the                     tured or marked to a packaging speci-
                                                                    requirements of this part, and each                       fication that was in effect on Sep-
                                                                    subsequent distributor of that pack-                      tember 30, 1991, and that was removed
                                                                    aging shall—                                              from this part 178 by a rule published
                                                                      (1) Notify in writing each person to                    in the FEDERAL REGISTER on December
                                                                    whom that packaging is transferred—                       21, 1990 and effective October 1, 1991.
                                                                      (i) Of all requirements in this part                    [Amdt. 178–97, 55 FR 52715, Dec. 21, 1990; 56 FR
                                                                    not met at the time of transfer, and                      66284, Dec. 20, 1991, as amended by Amdt. No.
                                                                      (ii) With information specifying the                    178–106, 59 FR 67519, Dec. 29, 1994; Amdt. 178–
                                                                    type(s) and dimensions of the closures,                   117, 62 FR 14338, Mar. 26, 1997; 68 FR 45041,
                                                                    including gaskets and any other com-                      July 31, 2003; 69 FR 34612, June 22, 2004]
                                                                    ponents needed to ensure that the
                                                                    packaging is capable of successfully                      § 178.3 Marking of packagings.
                                                                    passing the applicable performance                           (a) Each packaging represented as
                                                                    tests. This information must include                      manufactured to a DOT specification
                                                                    any procedures to be followed, includ-                    or a UN standard must be marked on a
                                                                    ing closure instructions for inner pack-                  non-removable component of the pack-
                                                                    agings and receptacles, to effectively                    aging with specification markings con-
                                                                    assemble and close the packaging for                      forming to the applicable specification,
                                                                    the purpose of preventing leakage in                      and with the following:
                                                                    transportation. For packagings sold or                       (1) In an unobstructed area, with let-
                                                                    represented as being in conformance                       ters, and numerals identifying the
                                                                    with the requirements of this sub-                        standards or specification (e.g. UN 1A1,
                                                                    chapter applicable to transportation by                   DOT 4B240ET, etc.).
                                                                    aircraft, this information must include                      (2) Unless otherwise specified in this
                                                                    relevant guidance to ensure that the                      part, with the name and address or
                                                                    packaging, as prepared for transpor-                      symbol of the packaging manufacturer
                                                                    tation, will withstand the pressure dif-                  or, where specifically authorized, the
                                                                    ferential requirements in ‘‘ 173.27 of                    symbol of the approval agency certi-
                                                                    this subchapter.                                          fying compliance with a UN standard.
                                                                      (2) Retain copies of each written no-                   Symbols, if used, must be registered
                                                                    tification for at least one year from                     with the Associate Administrator. Du-
                                                                    date of issuance; and                                     plicative symbols are not authorized.
                                                                      (3) Make copies of all written notifi-                     (3) The markings must be stamped,
                                                                    cations available for inspection by a                     embossed, burned, printed or otherwise
                                                                    representative of the Department.                         marked on the packaging to provide
                                                                      (d) Except as provided in paragraph                     adequate accessibility, permanency,
                                                                    (c) of this section, a packaging not con-                 contrast, and legibility so as to be
                                                                    forming to the applicable specifica-                      readily apparent and understood.
                                                                    tions or standards in this part may not                      (4) Unless otherwise specified, letters
                                                                    be marked to indicate such conform-                       and numerals must be at least 12.0 mm
                                                                    ance.                                                     (0.47 inches) in height except that for
                                                                      (e) Definitions. For the purpose of this                packagings of less than or equal to 30 L
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                                                                    part—                                                     (7.9 gallons) capacity for liquids or 30
                                                                      Manufacturer means the person whose                     kg (66 pounds) capacity for solids the
                                                                    name and address or symbol appears as                     height must be at least 6.0 mm (0.2

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                            § 178.33–5

                                                                    inches). For packagings having a ca-                      that special permit, an agent of the
                                                                    pacity of 5 L (1 gallon) or 5 kg (11                      holder or party for the purpose of
                                                                    pounds) or less, letters and numerals                     marking or certification, or a third
                                                                    must be of an appropriate size.                           party tester.
                                                                      (5) For packages with a gross mass of                   [Amdt. 178–97, 55 FR 52716, Dec. 21, 1990; 56 FR
                                                                    more than 30 kg (66 pounds), the mark-                    66284, Dec. 20, 1991, as amended by Amdt. No.
                                                                    ings or a duplicate thereof must appear                   178–106, 59 FR 67519, Dec. 29, 1994; Amdt. 178–
                                                                    on the top or on a side of the pack-                      113, 61 FR 21102, May 9, 1996; 65 FR 50462, Aug.
                                                                    aging.                                                    18, 2000; 66 FR 45386, Aug. 28, 2001; 67 FR 61015,
                                                                      (b) A UN standard packaging for                         Sept. 27, 2002; 68 FR 75748, Dec. 31, 2003; 70 FR
                                                                    which the UN standard is set forth in                     73166, Dec. 9, 2005]
                                                                    this part may be marked with the
                                                                    United Nations symbol and other speci-                                Subpart A [Reserved]
                                                                    fication markings only if it fully con-
                                                                    forms to the requirements of this part.                       Subpart B—Specifications for
                                                                    A UN standard packaging for which the                        Inside Containers, and Linings
                                                                    UN standard is not set forth in this
                                                                    part may be marked with the United                          SOURCE: 29 FR 18823, Dec. 29, 1964, unless
                                                                    Nations symbol and other specification                    otherwise noted. Redesignated at 32 FR 5606,
                                                                    markings for that standard as provided                    Apr. 5, 1967.
                                                                    in the ICAO Technical Instructions or
                                                                    the IMDG Code subject to the following                    § 178.33 Specification 2P; inner non-
                                                                    conditions:                                                   refillable metal receptacles.
                                                                      (1) The U.S. manufacturer must es-
                                                                                                                              § 178.33–1 Compliance.
                                                                    tablish that the packaging conforms to
                                                                    the applicable provisions of the ICAO                        (a) Required in all details.
                                                                    Technical Instructions (IBR, see § 171.7                     (b) [Reserved]
                                                                    of this subchapter) or the IMDG Code
                                                                    (IBR, see § 171.7 of this subchapter), re-                § 178.33–2 Type and size.
                                                                    spectively.                                                  (a) Single-trip inside containers.
                                                                      (2) If an indication of the name of the                 Must be seamless, or with seams, weld-
                                                                    manufacturer or other identification of                   ed, soldered, brazed, double seamed, or
                                                                    the packaging as specified by the com-                    swedged.
                                                                    petent authority is required, the name                       (b) The maximum capacity of con-
                                                                    and address or symbol of the manufac-                     tainers in this class shall not exceed
                                                                    turer or the approval agency certifying                   one liter (61.0 cubic inches). The max-
                                                                    compliance with the UN standard must                      imum inside diameter shall not exceed
                                                                    be entered. Symbols, if used, must be                     3 inches.
                                                                    registered with the Associate Adminis-                    [29 FR 18813, Dec. 29, 1964, as amended by
                                                                    trator.                                                   Order 71, 31 FR 9074, July 1, 1966. Redesig-
                                                                      (3) The letters ‘‘USA’’ must be used                    nated at 32 FR 5606, Apr. 5, 1967, and amended
                                                                    to indicate the State authorizing the                     by Amdt. 178–101, 58 FR 50237, Sept. 24, 1993;
                                                                    allocation of the specification marks if                  66 FR 45386, Aug. 28, 2001]
                                                                    the packaging is manufactured in the
                                                                    United States.                                            § 178.33–3 Inspection.
                                                                      (c) Where a packaging conforms to                          (a) By competent inspector.
                                                                    more than one UN standard or DOT                             (b) [Reserved]
                                                                    specification, the packaging may bear
                                                                    more than one marking, provided the                       § 178.33–4 Duties of inspector.
                                                                    packaging meets all the requirements                         (a) To inspect material and com-
                                                                    of each standard or specification.                        pleted containers and witness tests,
                                                                    Where more than one marking appears                       and to reject defective materials or
                                                                    on a packaging, each marking must ap-                     containers.
                                                                    pear in its entirety.                                        (b) [Reserved]
                                                                      (d) No person may mark or otherwise
                                                                    certify a packaging or container as                       § 178.33–5 Material.
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                                                                    meeting the requirements of a manu-                          (a) Uniform quality steel plate such
                                                                    facturing special permit unless that                      as black plate, electro-tin plate, hot
                                                                    person is the holder of or a party to                     dipped tin plate, tern plate or other

                                                                                                                         815



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                                                                    § 178.33–6                                                             49 CFR Ch. I (10–1–09 Edition)

                                                                    commercially accepted can making                          like material, size, design construc-
                                                                    plate; or nonferrous metal of uniform                     tion, finish, and quality.
                                                                    drawing quality.                                          [Order 71, 31 FR 9074, July 1, 1966. Redesig-
                                                                      (b) Material with seams, cracks, lam-                   nated at 32 FR 5606, Apr. 5, 1967, as amended
                                                                    inations or other injurious defects not                   by 66 FR 45387, Aug. 28, 2001]
                                                                    authorized.
                                                                                                                              § 178.33–9    Marking.
                                                                    § 178.33–6     Manufacture.                                 (a)    By    means    of    printing,
                                                                      (a) By appliances and methods that                      lithographing, embossing, or stamping,
                                                                    will assure uniformity of completed                       each container must be marked to
                                                                    containers; dirt and scale to be re-                      show:
                                                                    moved as necessary; no defect accept-                       (1) DOT-2P.
                                                                    able that is likely to weaken the fin-                      (2) Name or symbol of person making
                                                                    ished container appreciably; reason-                      the mark specified in paragraph (a)(1)
                                                                    ably smooth and uniform surface finish                    of this section. Symbol, if used, must
                                                                    required.                                                 be registered with the Associate Ad-
                                                                      (b) Seams when used must be as fol-                     ministrator.
                                                                    lows:                                                       (b) [Reserved]
                                                                      (1) Circumferential seams: By weld-                     [Amdt. 178–40, 41 FR 38181, Sept. 9, 1976, as
                                                                    ing, swedging, brazing, soldering, or                     amended by Amdt. 178–97, 56 FR 66287, Dec.
                                                                    double seaming.                                           20, 1991; 66 FR 45386, Aug. 28, 2001]
                                                                      (2) Side seams: By welding, brazing,
                                                                    or soldering.                                             § 178.33a Specification 2Q; inner non-
                                                                                                                                  refillable metal receptacles.
                                                                      (c) Ends: The ends shall be of pres-
                                                                    sure design.                                              § 178.33a–1     Compliance.
                                                                    [29 FR 18823, Dec. 29, 1964, as amended by                  (a) Required in all details.
                                                                    Order 71, 31 FR 9074, July 1, 1966. Redesig-                (b) [Reserved]
                                                                    nated at 32 FR 5606, Apr. 5, 1967]
                                                                                                                              [Order 71, 31 FR 9074, July 1, 1966. Redesig-
                                                                    § 178.33–7     Wall thickness.                            nated at 32 FR 5606, Apr. 5, 1967]

                                                                      (a) The minimum wall thickness for                      § 178.33a–2     Type and size.
                                                                    any container shall be 0.007 inch.
                                                                                                                                (a) Single-trip inside containers.
                                                                      (b) [Reserved]                                          Must be seamless, or with seams weld-
                                                                    [Order 71, 31 FR 9074, July 1, 1966. Redesig-             ed, soldered, brazed, double seamed, or
                                                                    nated at 32 FR 5606, Apr. 5, 1967]                        swedged.
                                                                                                                                (b) The maximum capacity of con-
                                                                    § 178.33–8     Tests.                                     tainers in this class shall not exceed 1
                                                                      (a) One out of each lot of 25,000 con-                  L (61.0 cubic inches). The maximum in-
                                                                    tainers or less, successively produced                    side diameter shall not exceed 3 inches.
                                                                    per day shall be pressure tested to de-                   [Order 71, 31 FR 9074, July 1, 1966. Redesig-
                                                                    struction and must not burst below 240                    nated at 32 FR 5606, Apr. 5, 1967, and amended
                                                                    psig gauge pressure. The container                        by Amdt. 178–43, 42 FR 42208, Aug. 22, 1977;
                                                                    tested shall be complete with end as-                     Amdt. 178–101, 58 FR 50237, Sept. 24, 1993; 66
                                                                                                                              FR 45387, Aug. 28, 2001]
                                                                    sembled.
                                                                      (b) Each such 25,000 containers or                      § 178.33a–3     Inspection.
                                                                    less, successively produced per day,
                                                                    shall constitute a lot and if the test                      (a) By competent inspector.
                                                                    container shall fail, the lot shall be re-                  (b) [Reserved]
                                                                    jected or ten additional containers may                   [Order 71, 31 FR 9074, July 1, 1966. Redesig-
                                                                    be selected at random and subjected to                    nated at 32 FR 5606, Apr. 5, 1967]
                                                                    the test under which failure occurred.
                                                                    These containers shall be complete                        § 178.33a–4     Duties of inspector.
                                                                    with ends assembled. Should any of the                      (a) To inspect material and com-
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                                                                    ten containers thus tested fail, the en-                  pleted containers and witness tests,
                                                                    tire lot must be rejected. All con-                       and to reject defective materials or
                                                                    tainers constituting a lot shall be of                    containers.

                                                                                                                         816



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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                          § 178.33b–4

                                                                      (b) [Reserved]                                          be selected at random and subjected to
                                                                    [Order 71, 31 FR 9074, July 1, 1966. Redesig-
                                                                                                                              the test under which failure occurred.
                                                                    nated at 32 FR 5606, Apr. 5, 1967]                        These containers shall be complete
                                                                                                                              with ends assembled. Should any of the
                                                                    § 178.33a–5 Material.                                     ten containers thus tested fail, the en-
                                                                       (a) Uniform quality steel plate such                   tire lot must be rejected. All con-
                                                                    as black plate, electrotin plate, hot                     tainers constituting a lot shall be of
                                                                    dipped tinplate, ternplate or other                       like material, size, design, construc-
                                                                    commercially accepted can making                          tion, finish and quality.
                                                                    plate; or nonferrous metal of uniform                     [Order 71, 31 FR 9074, July 1, 1966. Redesig-
                                                                    drawing quality.                                          nated at 32 FR 5606, Apr. 5, 1967, as amended
                                                                       (b) Material with seams, cracks, lam-                  by 66 FR 45387, Aug. 28, 2001]
                                                                    inations or other injurious defects not
                                                                    authorized.                                               § 178.33a–9     Marking.
                                                                    [Order 71, 31 FR 9074, July 1, 1966. Redesig-               (a)    By    means    of    printing,
                                                                    nated at 32 FR 5606, Apr. 5, 1967]                        lithographing, embossing, or stamping,
                                                                                                                              each container must be marked to
                                                                    § 178.33a–6 Manufacture.                                  show:
                                                                       (a) By appliances and methods that                       (1) DOT-2Q.
                                                                    will assure uniformity of completed                         (2) Name or symbol of person making
                                                                    containers; dirt and scale to be re-                      the mark specified in paragraph (a)(1)
                                                                    moved as necessary; no defect accept-                     of this section. Symbol, if used, must
                                                                    able that is likely to weaken the fin-                    be registered with the Associate Ad-
                                                                    ished container appreciably; reason-                      ministrator.
                                                                    ably smooth and uniform surface finish                      (b) [Reserved]
                                                                    required.                                                 [Amdt. 178–40, 41 FR 38181, Sept. 9, 1976, as
                                                                       (b) Seams when used must be as fol-                    amended by Amdt. 178–97, 56 FR 66287, Dec.
                                                                    lows:                                                     20, 1991; 66 FR 45386, Aug. 28, 2001]
                                                                       (1) Circumferential seams. By weld-
                                                                    ing, swedging, brazing, soldering, or                     § 178.33b Specification 2S; inner non-
                                                                    double seaming.                                               refillable plastic receptacles [Re-
                                                                       (2) Side seams. By welding, brazing or                     served]
                                                                    soldering.
                                                                       (c) Ends. The ends shall be of pres-                   § 178.33b–1     Compliance.
                                                                    sure design.                                                (a) Required in all details.
                                                                                                                                (b) [Reserved]
                                                                    [Order 71, 31 FR 9074, July 1, 1966. Redesig-
                                                                    nated at 32 FR 5606, Apr. 5, 1967]                        [74 FR 2268, Jan. 14, 2009]

                                                                    § 178.33a–7 Wall thickness.                               § 178.33b–2 Type and size.
                                                                       (a) The minimum wall thickness for                        (a) Single-trip inside containers.
                                                                    any container shall be 0.008 inch.                           (b) The maximum capacity of con-
                                                                       (b) [Reserved]                                         tainers in this class shall not exceed
                                                                    [Order 71, 31 FR 9074, July 1, 1966. Redesig-             one liter (61.0 cubic inches). The max-
                                                                    nated at 32 FR 5606, Apr. 5, 1967]                        imum inside diameter shall not exceed
                                                                                                                              3 inches.
                                                                    § 178.33a–8 Tests.
                                                                                                                              [74 FR 2268, Jan. 14, 2009]
                                                                       (a) One out of each lot of 25,000 con-
                                                                    tainers or less, successively produced                    § 178.33b–3 Inspection.
                                                                    per day, shall be pressure tested to de-                     (a) By competent inspector.
                                                                    struction and must not burst below 270                       (b) [Reserved]
                                                                    psig gauge pressure. The container
                                                                    tested shall be complete with end as-                     [74 FR 2268, Jan. 14, 2009]
                                                                    sembled.
                                                                       (b) Each such 25,000 containers or                     § 178.33b–4 Duties of inspector.
                                                                    less, successively produced per day,                         (a) To inspect material and com-
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                                                                    shall constitute a lot and if the test                    pleted containers and witness tests,
                                                                    container shall fail, the lot shall be re-                and to reject defective materials or
                                                                    jected or ten additional containers may                   containers.

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                                                                    § 178.33b–5                                                           49 CFR Ch. I (10–1–09 Edition)

                                                                      (b) [Reserved]                                          tested must be complete as intended
                                                                                                                              for transportation.
                                                                    [74 FR 2268, Jan. 14, 2009]
                                                                                                                                (2) Each such 5,000 containers or less,
                                                                    § 178.33b–5      Material.                                successively produced per day, shall
                                                                                                                              constitute a lot and if the test con-
                                                                      (a) The receptacles must be con-
                                                                                                                              tainer shall fail, the lot shall be re-
                                                                    structed of polyethylene terephthalate
                                                                    (PET), polyethylene napthalate (PEN),                     jected or ten additional containers may
                                                                    polyamide (Nylon) or a blend of PET,                      be selected at random and subjected to
                                                                    PEN, ethyl vinyl alcohol (EVOH) and/                      the test under which failure occurred.
                                                                    or Nylon.                                                 These containers shall be complete as
                                                                      (b) Material with seams, cracks, lam-                   intended for transportation. Should
                                                                    inations or other injurious defects are                   any of the ten containers thus tested
                                                                    forbidden.                                                fail, the entire lot must be rejected. All
                                                                                                                              containers constituting a lot shall be
                                                                    [74 FR 2268, Jan. 14, 2009]
                                                                                                                              of like material, size, design construc-
                                                                    § 178.33b–6      Manufacture.                             tion, finish, and quality.
                                                                                                                                (b) Leak Testing. (1) Each empty con-
                                                                      (a) Each container must be manufac-                     tainer must be subjected to a pressure
                                                                    tured by thermoplastic processes that                     equal to or in excess of the maximum
                                                                    will assure uniformity of the com-
                                                                                                                              expected in the filled containers at 55
                                                                    pleted container. No used material
                                                                                                                              °C (131 °F) or 50 °C (122 °F) if the liquid
                                                                    other than production residues or
                                                                    regrind from the same manufacturing                       phase does not exceed 95 percent of the
                                                                    process may be used. The packaging                        capacity of the container at 50 °C (122
                                                                    must be adequately resistant to aging                     °F). This must be at least two-thirds of
                                                                    and to degradation caused either by                       the design pressure of the aerosol dis-
                                                                    the substance contained or by ultra-                      penser. If any container shows evidence
                                                                    violet radiation.                                         of leakage at a rate equal to or greater
                                                                      (b) [Reserved]                                          than 3.3 × 10¥2mbar.l.s¥1 at 20 °C (68
                                                                                                                              °F), at the test pressure, distortion or
                                                                    [74 FR 2268, Jan. 14, 2009]
                                                                                                                              other defect, it must be rejected.
                                                                    § 178.33b–7      Design Qualification Test.                 (2) Prior to filling, the filler must en-
                                                                                                                              sure that the crimping equipment is
                                                                      (a) Drop Testing.                                       set appropriately and the specified pro-
                                                                      (1) To ensure that creep does not af-                   pellant is used. Once filled, each con-
                                                                    fect the ability of the container type to                 tainer must be weighed and leak test-
                                                                    retain the contents, each container
                                                                                                                              ed. The leak detection equipment must
                                                                    type shall be drop tested as follows:
                                                                                                                              be sufficiently sensitive to detect at
                                                                    three groups of twenty-five filled con-
                                                                                                                              least a leak rate of 2.0 × 10¥3mbar.l.s¥1
                                                                    tainers shall be dropped from 1.8m on
                                                                    to a rigid, non-resilient, flat and hori-                 at 20 °C (68 °F). Any filled container
                                                                    zontal surface. One group must be con-                    which shows evidence of leakage, defor-
                                                                    ditioned at 38 °C (100 °F) for 26 weeks,                  mation, or excessive weight must be re-
                                                                    the second group for 100 hours at 50 °C                   jected.
                                                                    (122 °F) and the third group for 18 hours                 [74 FR 2268, Jan. 14, 2009]
                                                                    at 55 °C (131 °F), prior to performing
                                                                    the drop test.                                            § 178.33b–9     Marking.
                                                                      (2) Criteria for passing the drop test:
                                                                                                                                (a) Each container must be clearly
                                                                    the containers must not break or leak.
                                                                                                                              and permanently marked to show:
                                                                      (b) [Reserved]
                                                                                                                                (1) DOT–2S.
                                                                    [74 FR 2268, Jan. 14, 2009]                                 (2) Name or symbol of person making
                                                                                                                              the mark specified in paragraph (a)(1)
                                                                    § 178.33b–8      Production Tests.
                                                                                                                              of this section. Symbol, if used, must
                                                                      (a) Burst Testing. (1) One out of each                  be registered with the Associate Ad-
                                                                    lot of 5,000 containers or less, succes-                  ministrator.
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                                                                    sively produced per day must be pres-                       (b) [Reserved]
                                                                    sure tested to destruction and must not
                                                                    burst below 240 psig. The container                       [74 FR 2268, Jan. 14, 2009]


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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.35

                                                                        Subpart C—Specifications for                            (3) Verify compliance of cylinders
                                                                                 Cylinders                                    with the applicable specification by—
                                                                                                                                (i) Verifying identification of mate-
                                                                    § 178.35 General     requirements                 for     rial is proper;
                                                                        specification cylinders.                                (ii) Inspecting the inside of the cyl-
                                                                      (a) Compliance. Compliance with the                     inder before closing in ends;
                                                                    requirements of this subpart is re-                         (iii) Verifying that the heat treat-
                                                                    quired in all details.                                    ment is proper;
                                                                      (b) Inspections and analyses. Chemical                    (iv) Obtaining samples for all tests
                                                                    analyses and tests required by this sub-                  and check chemical analyses (NOTE:
                                                                    chapter must be made within the                           Recommended locations for test speci-
                                                                    United States, unless otherwise ap-                       mens taken from welded cylinders are
                                                                    proved in writing by the Associate Ad-                    depicted in Figures 1 through 5 in Ap-
                                                                    ministrator, in accordance with sub-                      pendix C to this subpart for the specific
                                                                    part I of part 107 of this chapter. In-                   construction design.);
                                                                    spections and verification must be per-                     (v) Witnessing all tests;
                                                                    formed by—
                                                                                                                                (vi) Verify threads by gauge;
                                                                      (1) An independent inspection agency
                                                                                                                                (vii) Reporting volumetric capacity
                                                                    approved in writing by the Associate
                                                                                                                              and tare weight (see report form) and
                                                                    Administrator, in accordance with sub-
                                                                                                                              minimum thickness of wall noted; and
                                                                    part I of part 107 of this chapter; or
                                                                      (2) For DOT Specifications 3B, 3BN,                       (viii) Verifying that each cylinder is
                                                                    3E, 4B, 4BA, 4D (water capacity less                      marked in accordance with the applica-
                                                                    than 1,100 cubic inches), 4B240ET,                        ble specification.
                                                                    4AA480, 4L, 8, 8AL, 4BW, 39 (marked                         (4) Furnish complete test reports re-
                                                                    service pressure 900 p.s.i.g. or lower)                   quired by this subpart to the maker of
                                                                    and 4E manufactured in the United                         the cylinder and, upon request, to the
                                                                    States, a competent inspector of the                      purchaser. The test report must be re-
                                                                    manufacturer.                                             tained by the inspector for fifteen
                                                                      (c) Duties of inspector. The inspector                  years from the original test date of the
                                                                    shall determine that each cylinder                        cylinder.
                                                                    made is in conformance with the appli-                      (d) Defects and attachments. Cylinders
                                                                    cable specification. Except as other-                     must conform to the following:
                                                                    wise specified in the applicable speci-                     (1) A cylinder may not be constructed
                                                                    fication, the inspector shall perform                     of material with seams, cracks or lam-
                                                                    the following:                                            inations, or other injurious defects.
                                                                      (1) Inspect all material and reject                       (2) Metal attachments to cylinders
                                                                    any not meeting applicable require-                       must have rounded or chamfered cor-
                                                                    ments. For cylinders made by the bil-                     ners or must be protected in such a
                                                                    let-piercing process, billets must be in-
                                                                                                                              manner as to prevent the likelihood of
                                                                    spected and shown to be free from pipe,
                                                                                                                              causing puncture or damage to other
                                                                    cracks, excessive segregation and other
                                                                                                                              hazardous materials packages. This re-
                                                                    injurious defects after parting or, when
                                                                    applicable, after nick and cold break.                    quirement applies to anything tempo-
                                                                      (2) Verify the material of construc-                    rarily or permanently attached to the
                                                                    tion meets the requirements of the ap-                    cylinder, such as metal skids.
                                                                    plicable specification by—                                  (e) Safety devices. Pressure relief de-
                                                                      (i) Making a chemical analysis of                       vices and protection for valves, safety
                                                                    each heat of material;                                    devices, and other connections, if ap-
                                                                      (ii) Obtaining a certified chemical                     plied, must be as required or author-
                                                                    analysis from the material manufac-                       ized by the appropriate specification,
                                                                    turer for each heat of material (a ladle                  and as required in § 173.301 of this sub-
                                                                    analysis is acceptable); or                               chapter.
                                                                      (iii) If an analysis is not provided for                  (f) Markings. Markings on a DOT
                                                                    each heat of material by the material                     Specification cylinder must conform to
                                                                                                                              applicable requirements.
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                                                                    manufacturer, by making a check anal-
                                                                    ysis of a sample from each coil, sheet,                     (1) Each cylinder must be marked
                                                                    or tube.                                                  with the following information:

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                                                                    § 178.36                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                      (i) The DOT specification marking                          (6) Other markings are authorized
                                                                    must appear first, followed imme-                         provided they are made in low stress
                                                                    diately by the service pressure. For ex-                  areas other than the side wall and are
                                                                    ample, DOT-3A1800.                                        not of a size and depth that will create
                                                                      (ii) The serial number must be placed                   harmful stress concentrations. Such
                                                                    just below or immediately following                       marks may not conflict with any DOT
                                                                    the DOT specification marking.                            required markings.
                                                                      (iii) A symbol (letters) must be                           (g) Inspector’s report. Each inspector
                                                                    placed just below, immediately before                     shall prepare a report containing, at a
                                                                    or following the serial number. Other                     minimum, the applicable information
                                                                    variations in sequence of markings are                    listed in CGA Pamphlet C–11 (IBR, see
                                                                    authorized only when necessitated by a                    § 171.7 of this subchapter) or, until Oc-
                                                                    lack of space. The symbol and numbers                     tober 1, 1997, in accordance with the ap-
                                                                    must be those of the manufacturer.                        plicable test report requirements of
                                                                    The symbol must be registered with                        this subchapter in effect on September
                                                                    the Associate Administrator; duplica-                     30, 1996. Any additional information or
                                                                    tions are not authorized.                                 markings that are required by the ap-
                                                                      (iv) The inspector’s official mark and                  plicable specification must be shown
                                                                    date of test (such as 5–95 for May 1995)                  on the test report. The signature of the
                                                                    must be placed near the serial number.                    inspector on the reports certifies that
                                                                    This information must be placed so                        the processes of manufacture and heat
                                                                    that dates of subsequent tests can be                     treatment of cylinders were observed
                                                                    easily added. An example of the mark-                     and found satisfactory.
                                                                    ings prescribed in this paragraph (f)(1)                     (h) Report retention. The manufac-
                                                                    is as follows:                                            turer of the cylinders shall retain the
                                                                    DOT-3A1800                                                reports required by this subpart for 15
                                                                    1234                                                      years from the original test date of the
                                                                    XY                                                        cylinder.
                                                                    AB 5–95
                                                                      Or;                                                     [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                                                                              amended at 66 FR 45185, Aug. 28, 2001; 67 FR
                                                                    DOT-3A1800–1234–XY                                        51652, Aug. 8, 2002; 68 FR 75748, Dec. 31, 2003]
                                                                    AB 5–95
                                                                    Where:                                                    § 178.36 Specification 3A and              3AX
                                                                    DOT-3A = specification number                                 seamless steel cylinders.
                                                                    1800 = service pressure
                                                                    1234 = serial number                                        (a) Type size and service pressure. In
                                                                    XY = symbol of manufacturer                               addition to the requirements of § 178.35,
                                                                    AB = inspector’s mark                                     cylinders must conform to the fol-
                                                                    5–95 = date of test                                       lowing:
                                                                       (2) Additional required marking must                     (1) A DOT-3A cylinder is a seamless
                                                                    be applied to the cylinder as follows:                    steel cylinder with a water capacity
                                                                       (i) The word ‘‘spun’’ or ‘‘plug’’ must                 (nominal) not over 1,000 pounds and a
                                                                    be placed near the DOT specification                      service pressure of at least 150 psig.
                                                                    marking when an end closure in the                          (2) A DOT–3AX is a seamless steel
                                                                    finished cylinder has been welded by                      cylinder with a water capacity not less
                                                                    the spinning process, or effected by                      than 1,000 pounds and a service pres-
                                                                    plugging.                                                 sure of at least 500 psig, conforming to
                                                                       (ii) As prescribed in specification 3HT                the following requirements:
                                                                    (§ 178.44) or 3T (§ 178.45), if applicable.                 (i) Assuming the cylinder is to be
                                                                       (3) Marking exceptions. A DOT 3E cyl-                  supported horizontally at its two ends
                                                                    inder is not required to be marked with                   only and to be uniformly loaded over
                                                                    an inspector’s mark or a serial number.                   its entire length consisting of the
                                                                       (4) Unless otherwise specified in the                  weight per unit of length of the
                                                                    applicable specification, the markings                    straight cylindrical portion filled with
                                                                    on each cylinder must be stamped                          water and compressed to the specified
                                                                    plainly and permanently on the shoul-                     test pressure; the sum of two times the
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                                                                    der, top head, or neck.                                   maximum tensile stress in the bottom
                                                                       (5) The size of each marking must be                   fibers due to bending, plus that in the
                                                                    at least 0.25 inch or as space permits.                   same fibers (longitudinal stress), due to

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.36

                                                                    hydrostatic test may not exceed 80 per-                   the points of contact between the cyl-
                                                                    cent of the minimum yield strength of                     inder and floor when the cylinder is in
                                                                    the steel at such maximum stress. Wall                    a vertical position.
                                                                    thickness must be increased when nec-                       (e) Welding or brazing. Welding or
                                                                    essary to meet the requirement.                           brazing for any purpose whatsoever is
                                                                      (ii) To calculate the maximum longi-                    prohibited except as follows:
                                                                    tudinal tensile stress due to bending,                      (1) Welding or brazing is authorized
                                                                    the following formula must be used:                       for the attachment of neckrings and
                                                                    S=Mc/I                                                    footrings which are non-pressure parts
                                                                                                                              and only to the tops and bottoms of
                                                                      (iii) To calculate the maximum lon-                     cylinders having a service pressure of
                                                                    gitudinal tensile stress due to hydro-                    500 psig or less. Cylinders, neckrings,
                                                                    static test pressure, the following for-                  and footrings must be made of weldable
                                                                    mula must be used:                                        steel, the carbon content of which may
                                                                    S = A1 P/A2                                               not exceed 0.25 percent except in the
                                                                                                                              case of 4130X steel which may be used
                                                                    where:
                                                                                                                              with proper welding procedures.
                                                                    S = tensile stress—p.s.i.;                                  (2) As permitted in paragraph (d) of
                                                                    M = bending moment-inch pounds—(wl2)/8;
                                                                    w = weight per inch of cylinder filled with               this section.
                                                                      water;                                                    (3) Cylinders used solely in anhy-
                                                                    l = length of cylinder-inches;                            drous ammonia service may have a 1⁄2
                                                                    c = radius (D)/(2) of cylinder-inches;                    inch diameter bar welded within their
                                                                    I = moment of inertia—0.04909 (D4¥d4) inches              concave bottoms.
                                                                      fourth;                                                   (f) Wall thickness. For cylinders with
                                                                    D = outside diameter-inches;
                                                                    d = inside diameter-inches;
                                                                                                                              service pressure less than 900 psig, the
                                                                    A1 = internal area in cross section of cyl-               wall stress may not exceed 24,000 psig.
                                                                      inder-square inches;                                    A minimum wall thickness of 0.100 inch
                                                                    A2 = area of metal in cross section of cyl-               is required for any cylinder over 5
                                                                      inder-square inches;                                    inches outside diameter. Wall stress
                                                                    P=hydrostatic test pressure-psig.                         calculation must be made by using the
                                                                      (b) Steel. Open-hearth or electric steel                following formula:
                                                                    of uniform quality must be used. Con-                     S = [P(1.3D2+0.4d2)]/(D2¥d2)
                                                                    tent percent may not exceed the fol-
                                                                    lowing: Carbon, 0.55; phosphorous, 0.045;                 Where:
                                                                    sulphur, 0.050.                                           S = wall stress in psi;
                                                                      (c) Identification of material. Material                P = minimum test pressure prescribed for
                                                                    must be identified by any suitable                          water jacket test or 450 psig whichever is
                                                                                                                                the greater;
                                                                    method, except that plates and billets
                                                                                                                              D = outside diameter in inches;
                                                                    for hot-drawn cylinders must be                           d = inside diameter in inches.
                                                                    marked with the heat number.
                                                                      (d) Manufacture. Cylinders must be                        (g) Heat treatment. The completed cyl-
                                                                    manufactured using equipment and                          inder must be uniformly and properly
                                                                    processes adequate to ensure that each                    heat-treated prior to tests.
                                                                    cylinder produced conforms to the re-                       (h) Openings in cylinders and connec-
                                                                    quirements of this subpart. No fissure                    tions (valves, fuse plugs, etc.) for those
                                                                    or other defect is permitted that is                      openings. Threads are required on open-
                                                                    likely to weaken the finished cylinder                    ings.
                                                                    appreciably. A reasonably smooth and                        (1) Threads must be clean cut, even,
                                                                    uniform surface finish is required. If                    without checks, and to gauge.
                                                                    not originally free from such defects,                      (2) Taper threads, when used, must be
                                                                    the surface may be machined or other-                     of length not less than as specified for
                                                                    wise treated to eliminate these defects.                  American Standard taper pipe threads.
                                                                    The thickness of the bottoms of cyl-                        (3) Straight threads having at least 6
                                                                    inders welded or formed by spinning is,                   engaged     threads    are    authorized.
                                                                    under no condition, to be less than two                   Straight threads must have a tight fit
                                                                    times the minimum wall thickness of                       and calculated shear strength of at
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                                                                    the cylindrical shell; such bottom                        least 10 times the test pressure of the
                                                                    thicknesses must be measured within                       cylinder. Gaskets, adequate to prevent
                                                                    an area bounded by a line representing                    leakage, are required.

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                                                                    § 178.36                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                      (i) Hydrostatic test. Each cylinder                     length of 2 inches with a width of not
                                                                    must successfully withstand a hydro-                      over 11⁄2 inches, or a gauge length of at
                                                                    static test, as follows:                                  least 24 times thickness with width not
                                                                      (1) The test must be by water-jacket,                   over 6 times thickness is authorized
                                                                    or other suitable methods, operated so                    when cylinder wall is not over 3⁄16 inch
                                                                    as to obtain accurate data. The pres-                     thick.
                                                                    sure gauge must permit reading to an                        (ii) The specimen, exclusive of grip
                                                                    accuracy of 1 percent. The expansion                      ends, may not be flattened. Grip ends
                                                                    gauge must permit reading of total ex-                    may be flattened to within 1 inch of
                                                                    pansion to an accuracy of either 1 per-                   each end of the reduced section.
                                                                    cent or 0.1 cubic centimeter.                               (iii) When size of cylinder does not
                                                                      (2) Pressure must be maintained for                     permit securing straight specimens,
                                                                    at least 30 seconds and sufficiently                      the specimens may be taken in any lo-
                                                                    longer to ensure complete expansion.                      cation or direction and may be
                                                                    Any internal pressure applied after                       straightened or flattened cold, by pres-
                                                                    heat-treatment and previous to the of-                    sure only, not by blows. When speci-
                                                                    ficial test may not exceed 90 percent of                  mens are so taken and prepared, the in-
                                                                    the test pressure. If, due to failure of                  spector’s report must show in connec-
                                                                    the test apparatus the test pressure                      tion with record of physical tests de-
                                                                    cannot be maintained the test may be                      tailed information in regard to such
                                                                    repeated at a pressure increased by 10                    specimens.
                                                                    percent or 100 psig, whichever is the                       (iv) Heating of a specimen for any
                                                                    lower.                                                    purpose is not authorized.
                                                                      (3) Permanent, volumetric expansion                       (3) The yield strength in tension
                                                                    may not exceed 10 percent of the total                    must be the stress corresponding to a
                                                                    volumetric expansion at test pressure.                    permanent strain of 0.2 percent of the
                                                                      (4) Each cylinder must be tested to at                  gauge length. The following conditions
                                                                    least 5⁄3 times service pressure.                         apply:
                                                                      (j) Flattening test. A flattening test                    (i) The yield strength must be deter-
                                                                    must be performed on one cylinder                         mined by either the ‘‘offset’’ method or
                                                                    taken at random out of each lot of 200                    the ‘‘extension under load’’ method as
                                                                    or less, by placing the cylinder between                  prescribed in ASTM E 8 (IBR, see § 171.7
                                                                    wedge shaped knife edges having a 60°                     of this subchapter).
                                                                    included angle, rounded to 1⁄2-inch ra-                     (ii) In using the ‘‘extension under
                                                                    dius. The longitudinal axis of the cyl-                   load’’ method, the total strain (or ‘‘ex-
                                                                    inder must be at a 90-degree angle to                     tension under load’’) corresponding to
                                                                    knife edges during the test. For lots of                  the stress at which the 0.2-percent per-
                                                                    30 or less, flattening tests are author-                  manent strain occurs may be deter-
                                                                    ized to be made on a ring at least 8                      mined with sufficient accuracy by cal-
                                                                    inches long cut from each cylinder and                    culating the elastic extension of the
                                                                    subjected to same heat treatment as                       gauge length under appropriate load
                                                                    the finished cylinder.                                    and adding thereto 0.2 percent of the
                                                                      (k) Physical test. A physical test must                 gauge length. Elastic extension cal-
                                                                    be conducted to determine yield                           culations must be based on an elastic
                                                                    strength, tensile strength, elongation,                   modulus of 30,000,000. In the event of
                                                                    and reduction of area of material as                      controversy the entire stress-strain
                                                                    follows:                                                  diagram must be plotted and the yield
                                                                      (1) The test is required on 2 speci-                    strength determined from the 0.2 per-
                                                                    mens cut from 1 cylinder taken at ran-                    cent offset.
                                                                    dom out of each lot of 200 or less. For                     (iii) For the purpose of strain meas-
                                                                    lots of 30 or less, physical tests are au-                urement, the initial strain must be set
                                                                    thorized to be made on a ring at least                    while the specimen is under a stress of
                                                                    8 inches long cut from each cylinder                      12,000 psig and the strain indicator
                                                                    and subjected to same heat treatment                      reading must be set at the calculated
                                                                    as the finished cylinder.                                 corresponding strain.
                                                                      (2) Specimens must conform to the                         (iv) Cross-head speed of the testing
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                                                                    following:                                                machine may not exceed 1⁄8 inch per
                                                                      (i) Gauge length of 8 inches with a                     minute during yield strength deter-
                                                                    width of not over 11⁄2 inches, a gauge                    mination.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.37

                                                                       (l) Acceptable results for physical and                graph (m) of this section may be re-
                                                                    flattening tests. Either of the following                 moved from the spun cylinder category
                                                                    is an acceptable result:                                  by drilling to remove defective mate-
                                                                       (1) An elongation at least 40 percent                  rial, tapping and plugging.
                                                                    for a 2-inch gauge length or at least 20                  [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    percent in other cases and yield                          amended at 62 FR 51561, Oct. 1, 1997; 66 FR
                                                                    strength not over 73 percent of tensile                   45185, 45386–45387, Aug. 28, 2001; 67 FR 51652,
                                                                    strength. In this instance, the flat-                     Aug. 8, 2002; 68 FR 75748, Dec. 31, 2003; 73 FR
                                                                    tening test is not required.                              57006, Oct. 1, 2008]
                                                                       (2) An elongation at least 20 percent
                                                                    for a 2-inch gauge length or 10 percent                   § 178.37 Specification 3AA and 3AAX
                                                                                                                                    seamless steel cylinders.
                                                                    in other cases and a yield strength not
                                                                    over 73 percent of tensile strength. In                      (a) Type, size and service pressure. In
                                                                    this instance, the flattening test is re-                 addition to the requirements of § 178.35,
                                                                    quired, without cracking, to 6 times                      cylinders must conform to the fol-
                                                                    the wall thickness.                                       lowing:
                                                                       (m) Leakage test. All spun cylinders                      (1) A DOT-3AA cylinder is a seamless
                                                                    and plugged cylinders must be tested                      steel cylinder with a water capacity
                                                                    for leakage by gas or air pressure after                  (nominal) of not over 1,000 pounds and
                                                                    the bottom has been cleaned and is free                   a service pressure of at least 150 psig.
                                                                    from all moisture subject to the fol-                        (2) A DOT-3AAX cylinder is a seam-
                                                                    lowing conditions and limitations:                        less steel cylinder with a water capac-
                                                                       (1) Pressure, approximately the same                   ity of not less than 1,000 pounds and a
                                                                    as but no less than service pressure,                     service pressure of at least 500 psig,
                                                                    must be applied to one side of the fin-                   conforming to the following require-
                                                                    ished bottom over an area of at least                     ments:
                                                                    1⁄16 of the total area of the bottom but                     (i) Assuming the cylinder is to be
                                                                    not less than 3⁄4 inch in diameter, in-                   supported horizontally at its two ends
                                                                    cluding the closure, for at least 1                       only and to be uniformly loaded over
                                                                    minute, during which time the other                       its entire length consisting of the
                                                                    side of the bottom exposed to pressure                    weight per unit of length of the
                                                                    must be covered with water and closely                    straight cylindrical portion filled with
                                                                    examined for indications of leakage.                      water and compressed to the specified
                                                                    Except as provided in paragraph (n) of                    test pressure; the sum of two times the
                                                                    this section, a cylinder that is leaking                  maximum tensile stress in the bottom
                                                                    must be rejected.                                         fibers due to bending, plus that in the
                                                                       (2) A spun cylinder is one in which an                 same fibers (longitudinal stress), due to
                                                                    end closure in the finished cylinder has                  hydrostatic test pressure may not ex-
                                                                    been welded by the spinning process.                      ceed 80 percent of the minimum yield
                                                                       (3) A plugged cylinder is one in which                 strength of the steel at such maximum
                                                                    a permanent closure in the bottom of a                    stress. Wall thickness must be in-
                                                                    finished cylinder has been effected by a                  creased when necessary to meet the re-
                                                                    plug.                                                     quirement.
                                                                       (4) As a safety precaution, if the                        (ii) To calculate the maximum ten-
                                                                    manufacturer elects to make this test                     sile stress due to bending, the following
                                                                    before the hydrostatic test, the manu-                    formula must be used:
                                                                    facturer should design the test appa-                     S = Mc/I
                                                                    ratus so that the pressure is applied to
                                                                    the smallest area practicable, around                       (iii) To calculate the maximum lon-
                                                                    the point of closure, and so as to use                    gitudinal tensile stress due to hydro-
                                                                    the smallest possible volume of air or                    static test pressure, the following for-
                                                                    gas.                                                      mula must be used:
                                                                       (n) Rejected cylinders. Reheat treat-                  S = A1P/A2
                                                                    ment is authorized for rejected cyl-                      Where:
                                                                    inders. Subsequent thereto, cylinders
                                                                                                                              S = tensile stress-p.s.i.;
                                                                    must pass all prescribed tests to be ac-                  M = bending moment-inch pounds (wl2)/8;
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                                                                    ceptable. Repair by welding or spinning                   w = weight per inch of cylinder filled with
                                                                    is not authorized. Spun cylinders re-                       water;
                                                                    jected under the provisions of para-                      l = length of cylinder-inches;

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                                                                    § 178.37                                                                                                                     49 CFR Ch. I (10–1–09 Edition)
                                                                    c = radius (D)/(2) of cylinder-inches;                                                                 able, if satisfactory in all other re-
                                                                    I = moment of inertia-0.04909 (D4¥d4) inches                                                           spects, provided the tolerances shown
                                                                      fourth;
                                                                                                                                                                           in table 2 of this paragraph (b) are not
                                                                    D = outside diameter-inches;
                                                                    d = inside diameter-inches;                                                                            exceeded. When a carbon-boron steel is
                                                                    A1 = internal area in cross section of cyl-                                                            used, a hardenability test must be per-
                                                                      inder-square inches;                                                                                 formed on the first and last ingot of
                                                                    A2 = area of metal in cross section of cyl-                                                            each heat of steel. The results of this
                                                                      inder-square inches;                                                                                 test must be recorded on the Record of
                                                                    P = hydrostatic test pressure-psig.                                                                    Chemical Analysis of Material for Cyl-
                                                                      (b) Authorized steel. Open-hearth,                                                                   inders required by § 178.35. This hard-
                                                                    basic oxygen, or electric steel of uni-                                                                ness test must be made 5⁄16-inch from
                                                                    form quality must be used. A heat of                                                                   the quenched end of the Jominy quench
                                                                    steel made under the specifications in                                                                 bar and the hardness must be at least
                                                                    table 1 of this paragraph (b), check                                                                   Rc 33 and no more than Rc 53. The fol-
                                                                    chemical analysis of which is slightly                                                                 lowing chemical analyses are author-
                                                                    out of the specified range, is accept-                                                                 ized:
                                                                                                                                      TABLE 1—AUTHORIZED MATERIALS
                                                                                                       4130X (per-                NE–8630 (per-                                                                                                   Inter- mediate
                                                                                                                                                              9115 (percent)              9125 (percent)               Carbon-boron
                                                                          Designation                cent) (see Note              cent) (see Note                                                                                                  manganese
                                                                                                                                                               (see Note 1)                (see Note 1)                  (percent)
                                                                                                            1)                           1)                                                                                                          (percent)

                                                                    Carbon ...................       0.25/0.35 .........          0.28/0.33 .........         0.10/0.20      .........    0.20/0.30 .........         0.27–0.37 ........       0.40 max.
                                                                    Manganese ............           0.40/0.90 .........          0.70/0.90 .........         0.50/0.75      .........    0.50/0.75 .........         0.80–1.40 ........       1.35/1.65.
                                                                    Phosphorus ...........           0.04 max .........           0.04 max .........          0.04 max       .........    0.04 max .........          0.035 max .......        0.04 max.
                                                                    Sulfur .....................     0.05 max .........           0.04 max .........          0.04 max       .........    0.04 max .........          0.045 max .......        0.05 max.
                                                                    Silicon ....................     0.15/0.35 .........          0.20/0.35 .........         0.60/0.90      .........    0.60/0.90 .........         0.3 max. ..........      0.10/0.30.
                                                                    Chromium ..............          0.80/1.10 .........          0.40/0.60 .........         0.50/0.65      .........    0.50/0.65.
                                                                    Molybdenum ..........            0.15/0.25 .........          0.15/0.25
                                                                    Zirconium ...............        .........................    .........................   0.05/0.15 .........         0.05/0.15
                                                                    Nickel .....................     .........................    0.40/0.70.
                                                                    Boron .....................      .........................    .........................   .........................   .........................   0.0005/0.003.
                                                                       NOTE 1: This designation may not be restrictive and the commercial steel is limited in analysis as shown in this table.

                                                                                                                                 TABLE 2—CHECK ANALYSIS TOLERANCES
                                                                                                                                                                                                                                Tolerance (percent) over
                                                                                                                                                                                                                                 the maximum limit or
                                                                                                                                                              Limit or maximum specified                                        under the minimum limit
                                                                                             Element                                                                    (percent)
                                                                                                                                                                                                                               Under min-             Over max-
                                                                                                                                                                                                                               imum limit             imum limit

                                                                    Carbon ......................................................       To 0.15 incl ....................................................................                   0.02             0.03
                                                                                                                                        Over 0.15 to 0.40 incl ....................................................                           .03             .04
                                                                    Manganese ...............................................           To 0.60 incl ....................................................................                     .03             .03
                                                                                                                                        Over 0.60 to 1.15 incl ....................................................                         0.04             0.04
                                                                                                                                        Over 1.15 to 2.50 incl ....................................................                         0.05             0.05
                                                                    Phosphorus1 .............................................           All ranges .......................................................................     ....................           .01
                                                                    Sulphur .....................................................       All ranges .......................................................................     ....................           .01
                                                                    Silicon .......................................................     To 0.30 incl ....................................................................                     .02             .03
                                                                                                                                        Over 0.30 to 1.00 incl ....................................................                           .05             .05
                                                                    Nickel ........................................................     To 1.00 incl ....................................................................                     .03             .03
                                                                    Chromium .................................................          To 0.90 incl ....................................................................                     .03             .03
                                                                                                                                        0.90 to 2.90 incl .............................................................                       .05             .05
                                                                    Molybdenum .............................................            To 0.20 incl ....................................................................                     .01             .01
                                                                                                                                        Over 0.20 to 0.40 ...........................................................                         .02             .02
                                                                    Zirconium ..................................................        All ranges .......................................................................                    .01             .05
                                                                       1 Rephosphorized            steels not subject to check analysis for phosphorus.



                                                                      (c) Identification of material. Material                                                               (d) Manufacture. Cylinders must be
                                                                    must be identified by any suitable                                                                     manufactured using equipment and
                                                                    method except that plates and billets                                                                  processes adequate to ensure that each
                                                                    for hot-drawn cylinders must be                                                                        cylinder produced conforms to the re-
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                                                                    marked with the heat number.                                                                           quirements of this subpart. No fissure
                                                                                                                                                                           or other defects is permitted that is

                                                                                                                                                                   824



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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.37

                                                                    likely to weaken the finished cylinder                    d = inside diameter in inches.
                                                                    appreciably. A reasonably smooth and                        (g) Heat treatment. The completed cyl-
                                                                    uniform surface finish is required. If                    inders must be uniformly and properly
                                                                    not originally free from such defects,                    heat treated prior to tests. Heat treat-
                                                                    the surface may be machined or other-
                                                                                                                              ment of cylinders of the authorized
                                                                    wise treated to eliminate these defects.
                                                                                                                              analyses must be as follows:
                                                                    The thickness of the bottoms of cyl-
                                                                    inders welded or formed by spinning is,                     (1) All cylinders must be quenched by
                                                                    under no condition, to be less than two                   oil, or other suitable medium except as
                                                                    times the minimum wall thickness of                       provided in paragraph (g)(5) of this sec-
                                                                    the cylindrical shell; such bottom                        tion.
                                                                    thicknesses must be measured within                         (2) The steel temperature on quench-
                                                                    an area bounded by a line representing                    ing must be that recommended for the
                                                                    the points of contact between the cyl-                    steel analysis, but may not exceed 1750
                                                                    inder and floor when the cylinder is in                   °F.
                                                                    a vertical position.                                        (3) All steels must be tempered at a
                                                                      (e) Welding or brazing. Welding or                      temperature most suitable for that
                                                                    brazing for any purpose whatsoever is                     steel.
                                                                    prohibited except as follows:                               (4) The minimum tempering tempera-
                                                                      (1) Welding or brazing is authorized                    ture may not be less than 1000 °F ex-
                                                                    for the attachment of neckrings and                       cept as noted in paragraph (g)(6) of this
                                                                    footrings which are non-pressure parts,                   section.
                                                                    and only to the tops and bottoms of                         (5) Steel 4130X may be normalized at
                                                                    cylinders having a service pressure of                    a temperature of 1650 °F instead of
                                                                    500 psig or less. Cylinders, neckrings,                   being quenched and cylinders so nor-
                                                                    and footrings must be made of weldable                    malized need not be tempered.
                                                                    steel, the carbon content of which may                      (6) Intermediate manganese steels
                                                                    not exceed 0.25 percent except in the                     may be tempered at temperatures not
                                                                    case of 4130X steel which may be used                     less than 1150 °F., and after heat treat-
                                                                    with proper welding procedure.                            ing each cylinder must be submitted to
                                                                      (2) As permitted in paragraph (d) of                    a magnetic test to detect the presence
                                                                    this section.                                             of quenching cracks. Cracked cylinders
                                                                      (f) Wall thickness. The thickness of                    must be rejected and destroyed.
                                                                    each cylinder must conform to the fol-                      (7) Except as otherwise provided in
                                                                    lowing:                                                   paragraph (g)(6) of this section, all cyl-
                                                                      (1) For cylinders with a service pres-                  inders, if water quenched or quenched
                                                                    sure of less than 900 psig, the wall                      with a liquid producing a cooling rate
                                                                    stress may not exceed 24,000 psi. A min-                  in excess of 80 percent of the cooling
                                                                    imum wall thickness of 0.100 inch is re-                  rate of water, must be inspected by the
                                                                    quired for any cylinder with an outside                   magnetic particle, dye penetrant or ul-
                                                                    diameter of over 5 inches.                                trasonic method to detect the presence
                                                                      (2) For cylinders with service pres-                    of quenching cracks. Any cylinder de-
                                                                    sure of 900 psig or more the minimum                      signed to the requirements for speci-
                                                                    wall must be such that the wall stress                    fication 3AA and found to have a
                                                                    at the minimum specified test pressure                    quenching crack must be rejected and
                                                                    may not exceed 67 percent of the min-                     may not be requalified. Cylinders de-
                                                                    imum tensile strength of the steel as                     signed to the requirements for speci-
                                                                    determined from the physical tests re-                    fication 3AAX and found to have
                                                                    quired in paragraphs (k) and (l) of this                  cracks must have cracks removed to
                                                                    section and must be not over 70,000 psi.                  sound metal by mechanical means.
                                                                      (3) Calculation must be made by the                     Such specification 3AAX cylinders will
                                                                    formula:                                                  be acceptable if the repaired area is
                                                                    S = [P(1.3D2+0.4d2)]/(D2¥d2)                              subsequently examined to assure no de-
                                                                                                                              fect, and it is determined that design
                                                                    Where:
                                                                                                                              thickness requirements are met.
                                                                    S = wall stress in psi;
                                                                    P = minimum test pressure prescribed for                    (h) Openings in cylinders and connec-
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                                                                      water jacket test or 450 psig whichever is              tions (valves, fuse plugs, etc.) for those
                                                                      the greater;                                            openings. Threads are required on open-
                                                                    D = outside diameter in inches;                           ings.

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                                                                    § 178.37                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                      (1) Threads must be clean cut, even,                    and reduction of area of material as
                                                                    without checks, and to gauge.                             follows:
                                                                      (2) Taper threads, when used, must be                     (1) The test is required on 2 speci-
                                                                    of a length not less than as specified                    mens cut from 1 cylinder taken at ran-
                                                                    for American Standard taper pipe                          dom out of each lot of 200 or less. For
                                                                    threads.                                                  lots of 30 or less, physical tests are au-
                                                                      (3) Straight threads having at least 6                  thorized to be made on a ring at least
                                                                    engaged      threads    are    authorized.                8 inches long cut from each cylinder
                                                                    Straight threads must have a tight fit                    and subjected to the same heat treat-
                                                                    and a calculated shear strength of at                     ment as the finished cylinder.
                                                                    least 10 times the test pressure of the                     (2) Specimens must conform to the
                                                                    cylinder. Gaskets, adequate to prevent                    following:
                                                                    leakage, are required.                                      (i) Gauge length of 8 inches with a
                                                                      (i) Hydrostatic test. Each cylinder                     width of not over 11⁄2 inches, a gauge
                                                                    must successfully withstand a hydro-                      length of 2 inches with a width of not
                                                                    static test as follows:                                   over 11⁄2 inches, or a gauge length of at
                                                                                                                              least 24 times the thickness with width
                                                                      (1) The test must be by water-jacket,
                                                                                                                              not over 6 times thickness when the
                                                                    or other suitable method, operated so
                                                                                                                              thickness of the cylinder wall is not
                                                                    as to obtain accurate data. The pres-
                                                                                                                              over 3⁄16 inch.
                                                                    sure gauge must permit reading to an
                                                                                                                                (ii) The specimen, exclusive of grip
                                                                    accuracy of 1 percent. The expansion
                                                                                                                              ends, may not be flattened. Grip ends
                                                                    gauge must permit reading of total ex-
                                                                                                                              may be flattened to within 1 inch of
                                                                    pansion to an accuracy of either 1 per-
                                                                                                                              each end of the reduced section.
                                                                    cent or 0.1 cubic centimeter.
                                                                                                                                (iii) When size of cylinder does not
                                                                      (2) Pressure must be maintained for                     permit securing straight specimens,
                                                                    at least 30 seconds and sufficiently                      the specimens may be taken in any lo-
                                                                    longer to ensure complete expansion.                      cation or direction and may be
                                                                    Any internal pressure applied after                       straightened or flattened cold, by pres-
                                                                    heat-treatment and previous to the of-                    sure only, not by blows. When speci-
                                                                    ficial test may not exceed 90 percent of                  mens are so taken and prepared, the in-
                                                                    the test pressure. If, due to failure of                  spector’s report must show in connec-
                                                                    the test apparatus, the test pressure                     tion with record of physical tests de-
                                                                    cannot be maintained, the test may be                     tailed information in regard to such
                                                                    repeated at a pressure increased by 10                    specimens.
                                                                    percent or 100 psig, whichever is the                       (iv) Heating of a specimen for any
                                                                    lower.                                                    purpose is not authorized.
                                                                      (3) Permanent volumetric expansion                        (3) The yield strength in tension
                                                                    may not exceed 10 percent of total vol-                   must be the stress corresponding to a
                                                                    umetric expansion at test pressure.                       permanent strain of 0.2 percent of the
                                                                      (4) Each cylinder must be tested to at                  gauge length. The following conditions
                                                                    least 5⁄3 times the service pressure.                     apply:
                                                                      (j) Flattening test. A flattening test                    (i) The yield strength must be deter-
                                                                    must be performed on one cylinder                         mined by either the ‘‘offset’’ method or
                                                                    taken at random out of each lot of 200                    the ‘‘extension under load’’ method as
                                                                    or less, by placing the cylinder between                  prescribed in ASTM E 8 (IBR, see § 171.7
                                                                    wedge shaped knife edges having a 60°                     of this subchapter).
                                                                    included angle, rounded to 1⁄2-inch ra-                     (ii) In using the ‘‘extension under
                                                                    dius. The longitudinal axis of the cyl-                   load’’ method, the total strain (or ‘‘ex-
                                                                    inder must be at a 90-degree angle to                     tension under load’’) corresponding to
                                                                    knife edges during the test. For lots of                  the stress at which the 0.2 percent per-
                                                                    30 or less, flattening tests are author-                  manent strain occurs may be deter-
                                                                    ized to be made on a ring at least 8                      mined with sufficient accuracy by cal-
                                                                    inches long cut from each cylinder and                    culating the elastic extension of the
                                                                    subjected to same heat treatment as                       gauge length under appropriate load
                                                                    the finished cylinder.                                    and adding thereto 0.2 percent of the
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                                                                      (k) Physical test. A physical test must                 gauge length. Elastic extension cal-
                                                                    be conducted to determine yield                           culations must be based on an elastic
                                                                    strength, tensile strength, elongation,                   modulus of 30,000,000. In the event of

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.38

                                                                    controversy, the entire stress-strain                     inders. Subsequent thereto, cylinders
                                                                    diagram must be plotted and the yield                     must pass all prescribed tests to be ac-
                                                                    strength determined from the 0.2 per-                     ceptable. Repair by welding or spinning
                                                                    cent offset.                                              is not authorized. Spun cylinders re-
                                                                      (iii) For the purpose of strain meas-                   jected under the provision of paragraph
                                                                    urement, the initial strain must be set                   (m) of this section may be removed
                                                                    while the specimen is under a stress of                   from the spun cylinder category by
                                                                    12,000 psi, the strain indicator reading                  drilling to remove defective material,
                                                                    being set at the calculated cor-                          tapping and plugging.
                                                                    responding strain.                                        [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                      (iv) Cross-head speed of the testing                    amended at 65 FR 58631, Sept. 29, 2000; 66 FR
                                                                    machine may not exceed 1⁄8 inch per                       45386–45387, Aug. 28, 2001; 67 FR 51652, Aug. 8,
                                                                    minute during yield strength deter-                       2002; 68 FR 75748, Dec. 31, 2003]
                                                                    mination.
                                                                      (l) Acceptable results for physical and                 § 178.38 Specification      3B     seamless
                                                                    flattening tests. An acceptable result for                     steel cylinders.
                                                                    physical and flattening tests is elon-                       (a) Type, size, and service pressure. A
                                                                    gation at least 20 percent for 2 inches                   DOT 3B cylinder is seamless steel cyl-
                                                                    of gauge length or at least 10 percent in                 inder with a water capacity (nominal)
                                                                    other cases. Flattening is required,                      of not over 1,000 pounds and a service
                                                                    without cracking, to 6 times the wall                     pressure of at least 150 to not over 500
                                                                    thickness of the cylinder.                                psig.
                                                                      (m) Leakage test. All spun cylinders                       (b) Steel. Open-hearth or electric steel
                                                                    and plugged cylinders must be tested                      of uniform quality must be used. Con-
                                                                    for leakage by gas or air pressure after                  tent percent may not exceed the fol-
                                                                    the bottom has been cleaned and is free                   lowing: carbon, 0.55; phosphorus, 0.045;
                                                                    from all moisture. Pressure, approxi-                     sulphur, 0.050.
                                                                    mately the same as but no less than                          (c) Identification of material. Material
                                                                    the service pressure, must be applied to                  must be identified by any suitable
                                                                    one side of the finished bottom over an                   method except that plates and billets
                                                                    area of at least 1⁄16 of the total area of                for hot-drawn cylinders must be
                                                                    the bottom but not less than 3⁄4 inch in                  marked with the heat number.
                                                                    diameter, including the closure, for at                      (d) Manufacture. Cylinders must be
                                                                    least one minute, during which time                       manufactured using equipment and
                                                                    the other side of the bottom exposed to                   processes adequate to ensure that each
                                                                    pressure must be covered with water                       cylinder produced conforms to the re-
                                                                    and closely examined for indications of                   quirements of this subpart. No fissure
                                                                    leakage. Except as provided in para-                      or other defect is permitted that is
                                                                    graph (n) of this section, a cylinder                     likely to weaken the finished cylinder
                                                                    must be rejected if there is any leak-                    appreciably. A reasonably smooth and
                                                                    ing.                                                      uniform surface finish is required. If
                                                                      (1) A spun cylinder is one in which an                  not originally free from such defects,
                                                                    end closure in the finished cylinder has                  the surface may be machined or other-
                                                                    been welded by the spinning process.                      wise treated to eliminate these defects.
                                                                      (2) A plugged cylinder is one in which                  The thickness of the bottoms of cyl-
                                                                    a permanent closure in the bottom of a                    inders welded or formed by spinning is,
                                                                    finished cylinder has been effected by a                  under no condition, to be less than two
                                                                    plug.                                                     times the minimum wall thickness of
                                                                      (3) As a safety precaution, if the                      the cylindrical shell; such bottom
                                                                    manufacturer elects to make this test                     thicknesses to be measured within an
                                                                    before the hydrostatic test, the manu-                    area bounded by a line representing the
                                                                    facturer should design the test appa-                     points of contact between the cylinder
                                                                    ratus so that the pressure is applied to                  and floor when the cylinder is in a
                                                                    the smallest area practicable, around                     vertical position.
                                                                    the point of closure, and so as to use                       (e) Welding or brazing. Welding or
                                                                    the smallest possible volume of air or                    brazing for any purpose whatsoever is
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                                                                    gas.                                                      prohibited except as follows:
                                                                      (n) Rejected cylinders. Reheat treat-                      (1) Welding or brazing is authorized
                                                                    ment is authorized for rejected cyl-                      for the attachment of neckrings and

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                                                                    § 178.38                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    footrings which are non-pressure parts,                   Any internal pressure applied after
                                                                    and only to the tops and bottoms of                       heat-treatment and previous to the of-
                                                                    cylinders having a service pressure of                    ficial test may not exceed 90 percent of
                                                                    500 psig or less. Cylinders, neckrings,                   the test pressure. If, due to failure of
                                                                    and footrings must be made of weldable                    the test apparatus, the test pressure
                                                                    steel, carbon content of which may not                    cannot be maintained, the test may be
                                                                    exceed 0.25 percent except in the case                    repeated at a pressure increased by 10
                                                                    of 4130X steel which may be used with                     percent or 100 psig, whichever is the
                                                                    proper welding procedure.                                 lower.
                                                                      (2) As permitted in paragraph (d) of                      (3) Permanent volumetric expansion
                                                                    this section.                                             may not exceed 10 percent of total vol-
                                                                      (f) Wall thickness. The wall stress may                 umetric expansion at test pressure.
                                                                    not exceed 24,000 psi. The minimum                          (4) Cylinders must be tested as fol-
                                                                    wall thickness is 0.090 inch for any cyl-                 lows:
                                                                    inder with an outside diameter of 6                         (i) Each cylinder; to at least 2 times
                                                                    inches. Calculation must be made by                       service pressure; or
                                                                    the following formula:
                                                                                                                                (ii) 1 cylinder out of each lot of 200 or
                                                                    S = [P(1.3D2+0.4d2)]/(D2¥d2)                              less; to at least 3 times service pres-
                                                                    Where:                                                    sure. Others must be examined under
                                                                                                                              pressure of 2 times service pressure and
                                                                    S = wall stress in psi;
                                                                    P = at least two times service pressure or 450            show no defect.
                                                                      psig, whichever is the greater;                           (j) Flattening test. A flattening test
                                                                    D = outside diameter in inches;                           must be performed on one cylinder
                                                                    d = inside diameter in inches.                            taken at random out of each lot of 200
                                                                      (g) Heat treatment. The completed cyl-                  or less, by placing the cylinder between
                                                                    inders must be uniformly and properly                     wedge shaped knife edges having a 60°
                                                                    heat-treated prior to tests.                              included angle, rounded to 1⁄2-inch ra-
                                                                      (h) Openings in cylinders and connec-                   dius. The longitudinal axis of the cyl-
                                                                    tions (valves, fuse plugs, etc.) for those                inder must be at a 90-degree angle to
                                                                    openings. Threads, conforming to the                      knife edges during the test. For lots of
                                                                    following, are required on all openings:                  30 or less, flattening tests are author-
                                                                      (1) Threads must be clean cut, even,                    ized to be made on a ring at least 8
                                                                    without checks, and to gauge.                             inches long cut from each cylinder and
                                                                      (2) Taper threads when used, must be                    subjected to same heat treatment as
                                                                    of a length not less than as specified                    the finished cylinder.
                                                                    for American Standard taper pipe                            (k) Physical test. A physical test must
                                                                    threads.                                                  be conducted to determine yield
                                                                      (3) Straight threads having at least 4                  strength, tensile strength, elongation,
                                                                    engaged      threads   are    authorized.                 and reduction of area of material, as
                                                                    Straight threads must have a tight fit,                   follows:
                                                                    and calculated shear strength at least                      (1) The test is required on 2 speci-
                                                                    10 times the test pressure of the cyl-                    mens cut from 1 cylinder taken at ran-
                                                                    inder. Gaskets, adequate to prevent                       dom out of each lot of 200 or less. For
                                                                    leakage, are required.                                    lots of 30 or less, physical tests are au-
                                                                      (i) Hydrostatic test. Cylinders must                    thorized to be made on a ring at least
                                                                    successfully withstand a hydrostatic                      8 inches long cut from each cylinder
                                                                    test, as follows:                                         and subjected to same heat treatment
                                                                      (1) The test must be by water-jacket,                   as the finished cylinder.
                                                                    or other suitable method, operated so                       (2) Specimens must conform to the
                                                                    as to obtain accurate data. The pres-                     following:
                                                                    sure gauge must permit reading to an                        (i) Gauge length of 8 inches with a
                                                                    accuracy of 1 percent. The expansion                      width of not over 11⁄2 inches; or a gauge
                                                                    gauge must permit reading of total ex-                    length of 2 inches with a width of not
                                                                    pansion to an accuracy either of 1 per-                   over 11⁄2 inches; or a gauge length at
                                                                    cent or 0.1 cubic centimeter.                             least 24 times the thickness with a
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                                                                      (2) Pressure must be maintained for                     width not over 6 times thickness is au-
                                                                    at least 30 seconds and sufficiently                      thorized when a cylinder wall is not
                                                                    longer to insure complete expansion.                      over 3⁄16 inch thick.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.38

                                                                      (ii) The specimen, exclusive of grip                    yield strength not over 73 percent of
                                                                    ends, may not be flattened. Grip ends                     tensile strength. In this instance, the
                                                                    may be flattened to within one inch of                    flattening test is not required.
                                                                    each end of the reduced section.                             (2) An elongation of at least 20 per-
                                                                      (iii) When size of cylinder does not                    cent for a 2-inch gauge length or 10 per-
                                                                    permit securing straight specimens,                       cent in other cases and yield strength
                                                                    the specimens may be taken in any lo-                     not over 73 percent of tensile strength.
                                                                    cation or direction and may be                            Flattening is required, without crack-
                                                                    straightened or flattened cold, by pres-                  ing, to 6 times the wall thickness.
                                                                    sure only, not by blows. When speci-                         (m) Leakage test. All spun cylinders
                                                                    mens are so taken and prepared, the in-                   and plugged cylinders must be tested
                                                                    spector’s report must show in connec-                     for leakage by gas or air pressure after
                                                                    tion with record of physical tests de-                    the bottom has been cleaned and is free
                                                                    tailed information in regard to such                      from all moisture, subject to the fol-
                                                                    specimens.                                                lowing conditions and limitations:
                                                                      (iv) Heating of a specimen for any                         (1) Pressure, approximately the same
                                                                    purpose is not authorized.                                as but no less than service pressure,
                                                                      (3) The yield strength in tension                       must be applied to one side of the fin-
                                                                    must be the stress corresponding to a                     ished bottom over an area of at least
                                                                    permanent strain of 0.2 percent of the                    1⁄16 of the total area of the bottom but

                                                                    gauge length. The following conditions                    not less than 3⁄4 inch in diameter, in-
                                                                    apply:                                                    cluding the closure, for at least one
                                                                      (i) The yield strength must be deter-                   minute, during which time the other
                                                                    mined by either the ‘‘offset’’ method or                  side of the bottom exposed to pressure
                                                                    the ‘‘extension under load’’ method as                    must be covered with water and closely
                                                                    prescribed in ASTM E 8 (IBR, see § 171.7                  examined for indications of leakage.
                                                                    of this subchapter).                                      Except as provided in paragraph (n) of
                                                                      (ii) In using the ‘‘extension under                     this section, a cylinder must be re-
                                                                    load’’ method, the total strain (or ‘‘ex-                 jected if there is any leaking.
                                                                    tension under load’’) corresponding to                       (2) A spun cylinder is one in which an
                                                                    the stress at which the 0.2 percent per-                  end closure in the finished cylinder has
                                                                    manent strain occurs may be deter-                        been welded by the spinning process.
                                                                    mined with sufficient accuracy by cal-                       (3) A plugged cylinder is one in which
                                                                    culating the elastic extension of the                     a permanent closure in the bottom of a
                                                                    gauge length under appropriate load                       finished cylinder has been effected by a
                                                                    and adding thereto 0.2 percent of the                     plug.
                                                                    gauge length. Elastic extension cal-                         (4) As a safety precaution, if the
                                                                    culations must be based on an elastic                     manufacturer elects to make this test
                                                                    modulus of 30,000,000. In the event of                    before the hydrostatic test, he should
                                                                    controversy, the entire stress-strain                     design his apparatus so that the pres-
                                                                    diagram must be plotted and the yield                     sure is applied to the smallest area
                                                                    strength determined from the 0.2 per-                     practicable, around the point of clo-
                                                                    cent offset.                                              sure, and so as to use the smallest pos-
                                                                      (iii) For the purpose of strain meas-                   sible volume of air or gas.
                                                                    urement, the initial strain must be set                      (n) Rejected cylinders. Reheat treat-
                                                                    while the specimen is under a stress of                   ment of rejected cylinders is author-
                                                                    12,000 psi, and the strain indicator                      ized. Subsequent thereto, cylinders
                                                                    reading being set at the calculated cor-                  must pass all prescribed tests to be ac-
                                                                    responding strain.                                        ceptable. Repair by welding or spinning
                                                                      (iv) Cross-head speed of the testing                    is not authorized. Spun cylinders re-
                                                                    machine may not exceed 1⁄8 inch per                       jected under the provisions of para-
                                                                    minute during yield strength deter-                       graph (m) of this section may be re-
                                                                    mination.                                                 moved from the spun cylinder category
                                                                      (l) Acceptable results for physical and                 by drilling to remove defective mate-
                                                                    flattening tests. Either of the following                 rial, tapping and plugging.
                                                                    is an acceptable result:                                     (o) Marking. Markings may be
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                                                                      (1) An elongation of at least 40 per-                   stamped into the sidewalls of cylinders
                                                                    cent for a 2-inch gauge length or at                      having a service pressure of 150 psig if
                                                                    least 20 percent in other cases and                       all of the following conditions are met:

                                                                                                                         829



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                                                                    § 178.39                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                      (1) Wall stress at test pressure may                      (f) Wall thickness. The wall stress may
                                                                    not exceed 24,000 psi.                                    not exceed 15,000 psi. A minimum wall
                                                                      (2) Minimum wall thickness must be                      thickness of 0.100 inch is required for
                                                                    not less than 0.090 inch.                                 any cylinder over 5 inches in outside
                                                                      (3) Depth of stamping must be no                        diameter. Wall stress calculation must
                                                                    greater than 15 percent of the min-                       be made by using the following for-
                                                                    imum wall thickness, but may not ex-                      mula:
                                                                    ceed 0.015 inch.
                                                                      (4) Maximum outside diameter of cyl-                    S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)
                                                                    inder may not exceed 5 inches.                            Where:
                                                                      (5) Carbon content of cylinder may                      S = wall stress in psi;
                                                                    not exceed 0.25 percent. If the carbon                    P = minimum test pressure prescribed for
                                                                    content exceeds 0.25 percent, the com-                      water jacket test or 450 psig whichever is
                                                                    plete cylinder must be normalized after                     the greater;
                                                                    stamping.                                                 D = outside diameter in inches;
                                                                      (6) Stamping must be adjacent to the                    d = inside diameter in inches.
                                                                    top head.
                                                                                                                                (g) Heat treatment. The completed cyl-
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as             inders must be uniformly and properly
                                                                    amended by 66 FR 45185, 45386–45388, Aug. 28,             heat-treated prior to tests.
                                                                    2001; 67 FR 51652, Aug. 8, 2002; 68 FR 75748,               (h) Openings in cylinders and connec-
                                                                    Dec. 31, 2003]
                                                                                                                              tions (valves, fuse plugs, etc.) for those
                                                                    § 178.39 Specification 3BN seamless                       openings. Threads conforming to the
                                                                         nickel cylinders.                                    following are required on openings:
                                                                       (a) Type, size and service pressure. A                   (1) Threads must be clean cut, even,
                                                                    DOT 3BN cylinder is a seamless nickel                     without checks, and to gauge.
                                                                    cylinder with a water capacity (nomi-                       (2) Taper threads, when used, to be of
                                                                    nal) not over 125 pounds water capacity                   length not less than as specified for
                                                                    (nominal) and a service pressure at                       American Standard taper pipe threads.
                                                                    least 150 to not over 500 psig.                             (3) Straight threads having at least 6
                                                                       (b) Nickel. The percentage of nickel                   engaged      threads    are   authorized.
                                                                    plus cobalt must be at least 99.0 per-                    Straight threads must have a tight fit
                                                                    cent.                                                     and a calculated shear strength of at
                                                                       (c) Identification of material. The ma-                least 10 times the test pressure of the
                                                                    terial must be identified by any suit-                    cylinder. Gaskets, adequate to prevent
                                                                    able method except that plates and bil-                   leakage, are required.
                                                                    lets for hot-drawn cylinders must be                        (i) Hydrostatic test. Each cylinder
                                                                    marked with the heat number.                              must successfully withstand a hydro-
                                                                       (d) Manufacture. Cylinders must be                     static test, as follows:
                                                                    manufactured using equipment and                            (1) The test must be by water-jacket,
                                                                    processes adequate to ensure that each                    or other suitable method, operated so
                                                                    cylinder produced conforms to the re-                     as to obtain accurate data. The pres-
                                                                    quirements of this subpart. No defect is                  sure gauge must permit reading to an
                                                                    permitted that is likely to weaken the                    accuracy of 1 percent. The expansion
                                                                    finished cylinder appreciably. A rea-                     gauge must permit reading of total ex-
                                                                    sonably smooth and uniform surface                        pansion to an accuracy either of 1 per-
                                                                    finish is required. Cylinders closed in                   cent or 0.1 cubic centimeter.
                                                                    by spinning process are not authorized.                     (2) Pressure must be maintained for
                                                                       (e) Welding or brazing. Welding or                     at least 30 seconds and sufficiently
                                                                    brazing for any purpose whatsoever is                     longer to ensure complete expansion.
                                                                    prohibited except that welding is au-                     Any internal pressure applied after
                                                                    thorized     for    the   attachment    of                heat-treatment and previous to the of-
                                                                    neckrings and footrings which are non-                    ficial test may not exceed 90 percent of
                                                                    pressure parts, and only to the tops and                  the test pressure. If, due to failure of
                                                                    bottoms of cylinders. Neckrings and                       the test apparatus, the test pressure
                                                                    footrings must be of weldable material,                   cannot be maintained, the test may be
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                                                                    the carbon content of which may not                       repeated at a pressure increased by 10
                                                                    exceed 0.25 percent. Nickel welding rod                   percent or 100 psig, whichever is the
                                                                    must be used.                                             lower.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.39

                                                                      (3) Permanent volumetric expansion                        (3) The yield strength in tension
                                                                    may not exceed 10 percent of total vol-                   must be the stress corresponding to a
                                                                    umetric expansion at test pressure.                       permanent strain of 0.2 percent of the
                                                                      (4) Each cylinder must be tested to at                  gauge length. The following conditions
                                                                    least 2 times service pressure.                           apply:
                                                                      (j) Flattening test. A flattening test                    (i) The yield strength must be deter-
                                                                    must be performed on one cylinder                         mined by either the ‘‘offset’’ method or
                                                                    taken at random out of each lot of 200                    the ‘‘extension under load’’ method as
                                                                    or less, by placing the cylinder between                  prescribed in ASTM E 8 (IBR, see § 171.7
                                                                    wedge shaped knife edges having a 60°                     of this subchapter).
                                                                    included angle, rounded to 1⁄2-inch ra-
                                                                                                                                (ii) In using the ‘‘extension under
                                                                    dius. The longitudinal axis of the cyl-
                                                                    inder must be at a 90-degree angle to                     load’’ method, the total strain (or ‘‘ex-
                                                                    knife edges during the test. For lots of                  tension under load’’) corresponding to
                                                                    30 or less, flattening tests are author-                  the stress at which the 0.2 percent per-
                                                                    ized to be made on a ring at least 8                      manent strain occurs may be deter-
                                                                    inches long cut from each cylinder and                    mined with sufficient accuracy by cal-
                                                                    subjected to same heat treatment as                       culating the elastic extension of the
                                                                    the finished cylinder.                                    gauge length under appropriate load
                                                                      (k) Physical test. A physical test must                 and adding thereto 0.2 percent of the
                                                                    be conducted to determine yield                           gauge length. Elastic extension cal-
                                                                    strength, tensile strength, elongation,                   culations must be based on an elastic
                                                                    and reduction of area of material, as                     modulus of 30,000,000. In the event of
                                                                    follows:                                                  controversy, the entire stress-strain
                                                                      (1) The test is required on 2 speci-                    diagram must be plotted and the yield
                                                                    mens cut from 1 cylinder taken at ran-                    strength determined from the 0.2 per-
                                                                    dom out of each lot of 200 or less. For                   cent offset.
                                                                    lots of 30 or less, physical tests are au-                  (iii) For the purpose of strain meas-
                                                                    thorized to be made on a ring at least                    urement, the initial strain must be set
                                                                    8 inches long cut from each cylinder                      while the specimen is under a stress of
                                                                    and subjected to same heat treatment                      12,000 psi, and the strain indicator
                                                                    as the finished cylinder.
                                                                                                                              reading must be set at the calculated
                                                                      (2) Specimens must conform to the
                                                                                                                              corresponding strain.
                                                                    following:
                                                                      (i) A gauge length of 8 inches with a                     (iv) Cross-head speed of the testing
                                                                    width of not over 11⁄2 inches, a gauge                    machine may not exceed 1⁄8 inch per
                                                                    length of 2 inches with a width of not                    minute during yield strength deter-
                                                                    over 11⁄2 inches, or a gauge length of at                 mination.
                                                                    least 24 times the thickness with a                         (l) Acceptable results for physical and
                                                                    width not over 6 times thickness is au-                   flattening tests. Either of the following
                                                                    thorized when a cylinder wall is not                      is an acceptable result:
                                                                    over 3⁄16 inch thick.                                       (1) An elongation of at least 40 per-
                                                                      (ii) The specimen, exclusive of grip                    cent for a 2 inch gauge length or at
                                                                    ends, may not be flattened. Grip ends                     least 20 percent in other cases and
                                                                    may be flattened to within one inch of                    yield point not over 50 percent of ten-
                                                                    each end of the reduced section.                          sile strength. In this instance, the flat-
                                                                      (iii) When size of cylinder does not                    tening test is not required.
                                                                    permit securing straight specimens,                         (2) An elongation of at least 20 per-
                                                                    the specimens may be taken in any lo-                     cent for a 2 inch gauge length or 10 per-
                                                                    cation or direction and may be                            cent in other cases and a yield point
                                                                    straightened or flattened cold, by pres-                  not over 50 percent of tensile strength.
                                                                    sure only, not by blows. When speci-
                                                                                                                              Flattening is required, without crack-
                                                                    mens are so taken and prepared, the in-
                                                                                                                              ing, to 6 times the wall thickness.
                                                                    spector’s report must show in connec-
                                                                    tion with record of physical tests de-                      (m) Rejected cylinders. Reheat treat-
                                                                    tailed information in regard to such                      ment is authorized for rejected cyl-
                                                                                                                              inders. Subsequent thereto, cylinders
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                                                                    specimens.
                                                                      (iv) Heating of a specimen for any
                                                                    purpose is not authorized.

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                                                                    § 178.42                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    must pass all prescribed tests to be ac-                    (1) One cylinder out of each lot of 500
                                                                    ceptable. Repair by welding is not au-                    or less must be subjected to a hydro-
                                                                    thorized.                                                 static pressure of 6,000 psig or higher.
                                                                                                                                (2) The cylinder referred to in para-
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    amended by 66 FR 45185, 45386, 45388, Aug. 28,            graph (f)(1) of this section must burst
                                                                    2001; 67 FR 51652, Aug. 8, 2002; 68 FR 75748,             at a pressure higher than 6,000 psig
                                                                    Dec. 31, 2003]                                            without fragmenting or otherwise
                                                                                                                              showing lack of ductility, or must hold
                                                                    § 178.42 Specification 3E seamless steel                  a pressure of 12,000 psig for 30 seconds
                                                                        cylinders.                                            without bursting. In which case, it
                                                                      (a) Type, size, and service pressure. A                 must be subjected to a flattening test
                                                                    DOT 3E cylinder is a seamless steel                       without cracking to six times wall
                                                                    cylinder with an outside diameter not                     thickness between knife edges, wedge
                                                                    greater than 2 inches nominal, a length                   shaped 60 degree angle, rounded out to
                                                                    less than 2 feet and a service pressure                   a 1⁄2 inch radius. The inspector’s report
                                                                    of 1,800 psig.                                            must be suitably changed to show re-
                                                                                                                              sults of latter alternate and flattening
                                                                      (b) Steel. Open-hearth or electric steel
                                                                                                                              test.
                                                                    of uniform quality must be used. Con-
                                                                    tent percent may not exceed the fol-                        (3) Other cylinders must be examined
                                                                    lowing: Carbon, 0.55; phosphorus, 0.045;                  under pressure of at least 3,000 psig and
                                                                    sulphur, 0.050.                                           not to exceed 4,500 psig and show no de-
                                                                                                                              fect. Cylinders tested at a pressure in
                                                                      (c) Identification of steel. Materials
                                                                                                                              excess of 3,600 psig must burst at a
                                                                    must be identified by any suitable
                                                                                                                              pressure higher than 7,500 psig when
                                                                    method.
                                                                                                                              tested as specified in paragraph (f)(2) of
                                                                      (d) Manufacture. Cylinders must be                      this section. The pressure must be
                                                                    manufactured by best appliances and                       maintained for at least 30 seconds and
                                                                    methods. No defect is permitted that is                   sufficiently longer to ensure complete
                                                                    likely to weaken the finished cylinder                    examination.
                                                                    appreciably. A reasonably smooth and                        (g) Leakage test. All spun cylinders
                                                                    uniform surface finish is required. The                   and plugged cylinders must be tested
                                                                    thickness of the spun bottom is, under                    for leakage by gas or air pressure after
                                                                    no condition, to be less than two times                   the bottom has been cleaned and is free
                                                                    the minimum wall thickness of the cy-                     from all moisture subject to the fol-
                                                                    lindrical shell; such bottom thickness                    lowing conditions and limitations:
                                                                    must be measured within an area
                                                                                                                                (1) A pressure, approximately the
                                                                    bounded by a line representing the
                                                                                                                              same as but not less than the service
                                                                    points of contact between the cylinder                    pressure, must be applied to one side of
                                                                    and floor when the cylinder is in a                       the finished bottom over an area of at
                                                                    vertical position.                                        least 1⁄16 of the total area of the bottom
                                                                      (e) Openings in cylinders and connec-                   but not less than 3⁄4 inch in diameter,
                                                                    tions (valves, fuse plugs, etc.) for those                including the closure, for at least one
                                                                    openings. Threads conforming to the                       minute, during which time the other
                                                                    following are required on openings.                       side of the bottom exposed to pressure
                                                                      (1) Threads must be clean cut, even,                    must be covered with water and closely
                                                                    without checks, and to gauge.                             examined for indications of leakage.
                                                                      (2) Taper threads, when used, must be                   Accept as provided in paragraph (h) of
                                                                    of length not less than as specified for                  this section, a cylinder must be re-
                                                                    American Standard taper pipe threads.                     jected if there is any leakage.
                                                                      (3) Straight threads having at least 4                    (2) A spun cylinder is one in which an
                                                                    engaged      threads    are    authorized.                end closure in the finished cylinder has
                                                                    Straight threads must have a tight fit                    been welded by the spinning process.
                                                                    and a calculated shear strength of at                       (3) A plugged cylinder is one in which
                                                                    least 10 times the test pressure of the                   a permanent closure in the bottom of a
                                                                    cylinder. Gaskets, adequate to prevent                    finished cylinder has been effected by a
                                                                    leakage, are required.
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                                                                                                                              plug.
                                                                      (f) Hydrostatic test. Cylinders must be                   (4) As a safety precaution, if the
                                                                    tested as follows:                                        manufacturer elects to make this test

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                                                                  § 178.44

                                                                    before the hydrostatic test, the manu-                                                  TABLE 2—CHECK ANALYSIS TOLERANCES
                                                                    facturer shall design the test apparatus
                                                                                                                                                                                                                  Tolerance
                                                                    so that the pressure is applied to the                                                                                                    (percent) over the
                                                                    smallest area practicable, around the                                                                                                      maximum limit or
                                                                                                                                                                                                                  under the
                                                                    point of closure, and so as to use the                                                                     Limit or maximum                 minimum limit
                                                                                                                                                          Element
                                                                    smallest possible volume of air or gas.                                                                    specified (percent)
                                                                                                                                                                                                               Under            Over
                                                                       (h) Rejected cylinders. Reheat treat-                                                                                                    min-            max-
                                                                    ment is authorized for rejected cyl-                                                                                                       imum            imum
                                                                                                                                                                                                                limit           limit
                                                                    inders. Subsequent thereto, cylinders
                                                                    must pass all prescribed tests to be ac-                                          Carbon ...........     Over 0.15 to 0.40 incl                    .03         .04
                                                                    ceptable. Repair by welding or spinning                                           Manganese ....         To 0.60 incl ................             .03         .03
                                                                    is not authorized. Spun cylinders re-                                             Phosphorus1 ..         All ranges ..................    ..............       .01
                                                                                                                                                      Sulphur ..........     All ranges ..................    ..............       .01
                                                                    jected under the provisions of para-                                              Silicon ............   To 0.30 incl ................             .02         .03
                                                                    graph (g) of this section may be re-                                                                     Over 0.30 to 1.00 incl                    .05         .05
                                                                    moved from the spun cylinder category                                             Chromium ......        To 0.90 incl ................             .03         .03
                                                                    by drilling to remove defective mate-                                                                    Over 0.90 to 2.10 incl                    .05         .05
                                                                                                                                                      Molybdenum ..          To 0.20 incl ................             .01         .01
                                                                    rial, tapping and plugging.                                                                              Over 0.20 to 0.40 incl                    .02         .02
                                                                       (i) Marking. Markings required by
                                                                                                                                                        1 Rephosphorized steels not subject to check analysis for
                                                                    § 178.35 must be stamped plainly and                                              phosphorus.
                                                                    permanently on the shoulder, top head,
                                                                    neck or sidewall of each cylinder.                                                  (c) Identification of material. Material
                                                                                                                                                      must be identified by any suitable
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as                                     method. Steel stamping of heat identi-
                                                                    amended by 66 FR 45386, Aug. 28, 2001]                                            fications may not be made in any area
                                                                                                                                                      which will eventually become the side
                                                                    § 178.44 Specification 3HT seamless
                                                                        steel cylinders for aircraft use.                                             wall of the cylinder. Depth of stamping
                                                                                                                                                      may not encroach upon the minimum
                                                                      (a) Type, size and service pressure. A                                          prescribed wall thickness of the cyl-
                                                                    DOT 3HT cylinder is a seamless steel                                              inder.
                                                                    cylinder with a water capacity (nomi-                                               (d) Manufacture. Cylinders must be
                                                                    nal) of not over 150 pounds and a serv-                                           manufactured using equipment and
                                                                    ice pressure of at least 900 psig.                                                processes adequate to ensure that each
                                                                      (b) Authorized steel. Open hearth or                                            cylinder produced conforms to the re-
                                                                    electric furnace steel of uniform qual-                                           quirements of this subpart. No fissure
                                                                    ity must be used. A heat of steel made                                            or other defect is permitted that is
                                                                    under the specifications listed in Table                                          likely to weaken the finished container
                                                                    1 in this paragraph (b), a check chem-                                            appreciably. The general surface finish
                                                                    ical analysis that is slightly out of the                                         may not exceed a roughness of 250
                                                                    specified range is acceptable, if satis-                                          RMS. Individual irregularities such as
                                                                    factory in all other respects, provided                                           draw marks, scratches, pits, etc.,
                                                                    the tolerances shown in Table 2 in this                                           should be held to a minimum con-
                                                                    paragraph (b) are not exceeded. The                                               sistent with good high stress pressure
                                                                    maximum grain size shall be 6 or finer.                                           vessel manufacturing practices. If the
                                                                    The grain size must be determined in                                              cylinder is not originally free of such
                                                                    accordance with ASTM E 112–88 (IBR,                                               defects or does not meet the finish re-
                                                                    see § 171.7 of this subchapter). Steel of                                         quirements, the surface may be ma-
                                                                    the following chemical analysis is au-                                            chined or otherwise treated to elimi-
                                                                    thorized:                                                                         nate these defects. The point of closure
                                                                                                                                                      of cylinders closed by spinning may not
                                                                                 TABLE 1—AUTHORIZED MATERIALS                                         be less than two times the prescribed
                                                                                                                                    AISI 4130         wall thickness of the cylindrical shell.
                                                                                       Designation                                  (percent)         The cylinder end contour must be hem-
                                                                                                                                                      ispherical or ellipsoidal with a ratio of
                                                                    Carbon ...............................................     0.28/0.33
                                                                    Manganese ........................................         0.40/0.60              major-to-minor axis not exceeding two
                                                                    Phosphorus ........................................        0.040 maximum          to one and with the concave side to
                                                                    Sulfur .................................................   0.040 maximum          pressure.
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                                                                    Silicon ................................................   0.15/0.35                (e) Welding or brazing. Welding or
                                                                    Chromium ..........................................        0.80/1.10              brazing for any purpose whatsoever is
                                                                    Molybdenum ......................................          0.15/0.25
                                                                                                                                                      prohibited, except that welding by

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                                                                    § 178.44                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    spinning is permitted to close the bot-                   National Gas Tapered Thread (NGT) as
                                                                    tom of spun cylinders. Machining or                       required by American Standard Com-
                                                                    grinding to produce proper surface fin-                   pressed Gas Cylinder Valve Outlet and
                                                                    ish at point of closure is required.                      Inlet Connections.
                                                                      (f) Wall thickness. (1) Minimum wall                       (3) Straight threads having at least 6
                                                                    thickness for any cylinder must be                        engaged      threads    are    authorized.
                                                                    0.050 inch. The minimum wall thick-                       Straight threads must have a tight fit
                                                                    ness must be such that the wall stress                    and a calculated shear stress of at least
                                                                    at the minimum specified test pressure                    10 times the test pressure of the cyl-
                                                                    may not exceed 75 percent of the min-                     inder. Gaskets, adequate to prevent
                                                                    imum tensile strength of the steel as                     leakage, are required.
                                                                    determined from the physical tests re-                       (i) Hydrostatic test. Each cylinder
                                                                    quired in paragraph (m) of this section                   must withstand a hydrostatic test, as
                                                                    and may not be over 105,000 psi.                          follows:
                                                                      (2) Calculations must be made by the                       (1) The test must be by water-jacket,
                                                                    formula:                                                  or other suitable method, operated so
                                                                    S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)                        as to obtain accurate data. Pressure
                                                                                                                              gauge must permit reading to an accu-
                                                                    Where:
                                                                                                                              racy of 1 percent. The expansion gauge
                                                                    S = Wall stress in psi;
                                                                                                                              must permit reading of total expansion
                                                                    P = Minimum test pressure prescribed for
                                                                      water jacket test;                                      to an accuracy either of 1 percent of 0.1
                                                                    D = Outside diameter in inches;                           cubic centimeter.
                                                                    d = Inside diameter in inches.                               (2) Pressure must be maintained for
                                                                                                                              at least 30 seconds and sufficiently
                                                                      (3) Wall thickness of hemispherical
                                                                                                                              longer to ensure complete expansion.
                                                                    bottoms only permitted to 90 percent
                                                                                                                              Any internal pressure applied after
                                                                    of minimum wall thickness of cylinder
                                                                                                                              heat treatment and previous to the of-
                                                                    sidewall but may not be less than 0.050
                                                                                                                              ficial test may not exceed 90 percent of
                                                                    inch. In all other cases, thickness to be
                                                                                                                              the test pressure. If, due to failure of
                                                                    no less than prescribed minimum wall.
                                                                                                                              the test apparatus, the test pressure
                                                                      (g) Heat treatment. The completed cyl-
                                                                                                                              cannot be maintained, the test may be
                                                                    inders must be uniformly and properly
                                                                                                                              repeated at a pressure increased by 10
                                                                    heated prior to tests. Heat treatment
                                                                                                                              percent or 100 psig, which ever is the
                                                                    of the cylinders of the authorized anal-
                                                                                                                              lower.
                                                                    ysis must be as follows:
                                                                      (1) All cylinders must be quenched by                      (3) Permanent volumetric expansion
                                                                    oil, or other suitable medium.                            may not exceed 10 percent of total vol-
                                                                      (2) The steel temperature on quench-                    umetric expansion at test pressure.
                                                                    ing must be that recommended for the                         (4) Each cylinder must be tested to at
                                                                    steel analysis, but may not exceed                        least 5⁄3 times service pressure.
                                                                    1750 °F.                                                     (j) Cycling tests. Prior to the initial
                                                                      (3) The steel must be tempered at a                     shipment of any specific cylinder de-
                                                                    temperature most suitable for the par-                    sign, cyclic pressurization tests must
                                                                    ticular steel analysis but not less than                  have been performed on at least three
                                                                    850 °F.                                                   representative samples without failure
                                                                      (4) All cylinders must be inspected by                  as follows:
                                                                    the magnetic particle or dye penetrant                       (1) Pressurization must be performed
                                                                    method to detect the presence of                          hydrostatically between approximately
                                                                    quenching cracks. Any cylinder found                      zero psig and the service pressure at a
                                                                    to have a quenching crack must be re-                     rate not in excess of 10 cycles per
                                                                    jected and may not be requalified.                        minute. Adequate recording instrumen-
                                                                      (h) Openings in cylinders and connec-                   tation must be provided if equipment is
                                                                    tions (valves, fuse plugs, etc.) for those                to be left unattended for periods of
                                                                    openings. Threads conforming to the                       time.
                                                                    following are required on openings:                          (2) Tests prescribed in paragraph
                                                                      (1) Threads must be clean cut, even,                    (j)(1) of this section must be repeated
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                                                                    without cracks, and to gauge.                             on one random sample out of each lot
                                                                      (2) Taper threads, when used, must be                   of cylinders. The cylinder may then be
                                                                    of length not less than as specified for                  subjected to a burst test.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.44

                                                                      (3) A lot is defined as a group of cyl-                 permanent strain of 0.2 percent of the
                                                                    inders fabricated from the same heat of                   gauge length.
                                                                    steel, manufactured by the same proc-                        (i) The yield strength must be deter-
                                                                    ess and heat treated in the same equip-                   mined by either the ‘‘offset’’ method or
                                                                    ment under the same conditions of                         the ‘‘extension under load’’ method as
                                                                    time, temperature, and atmosphere,                        prescribed in ASTM E 8 (IBR, see § 171.7
                                                                    and may not exceed a quantity of 200                      of this subchapter).
                                                                    cylinders.                                                   (ii) In using the ‘‘extension under
                                                                      (4) All cylinders used in cycling tests                 load’’ method, the total strain (or ‘‘ex-
                                                                    must be destroyed.                                        tension under load’’) corresponding to
                                                                      (k) Burst test. One cylinder taken at                   the stress at which the 0.2 percent per-
                                                                    random out of each lot of cylinders                       manent strain occurs may be deter-
                                                                    must be hydrostatically tested to de-                     mined with sufficient accuracy by cal-
                                                                    struction.                                                culating the elastic extension of the
                                                                      (l) Flattening test. A flattening test                  gauge length under appropriate load
                                                                    must be performed on one cylinder                         and adding thereto 0.2 percent of the
                                                                    taken at random out of each lot of 200                    gauge length. Elastic extension cal-
                                                                    or less, by placing the cylinder between                  culations must be based on an elastic
                                                                    wedge shaped knife edges having a 60°                     modulus of 30,000,000. In the event of
                                                                    included angle, rounded to 1⁄2-inch ra-                   controversy, the entire stress-strain
                                                                    dius. The longitudinal axis of the cyl-                   diagram must be plotted and the yield
                                                                    inder must be at a 90-degree angle to                     strength determined from the 0.2 per-
                                                                    knife edges during the test. For lots of                  cent offset.
                                                                    30 or less, flattening tests are author-                     (iii) For the purpose of strain meas-
                                                                    ized to be made on a ring at least 8                      urement, the initial strain must be set
                                                                    inches long cut from each cylinder and                    while the specimen is under a stress of
                                                                    subjected to same heat treatment as                       12,000 psi, the strain indicator reading
                                                                    the finished cylinder.                                    being set at the calculated cor-
                                                                      (m) Physical tests. A physical test                     responding strain.
                                                                    must be conducted to determine yield                         (iv) Cross-head speed of the testing
                                                                    strength, tensile strength, elongation,                   machine may not exceed 1⁄8 inch per
                                                                    and reduction of area of material, as                     minute during yield strength deter-
                                                                    follows:                                                  mination.
                                                                      (1) Test is required on 2 specimens                        (n) Magnetic particle inspection. In-
                                                                    cut from 1 cylinder taken at random                       spection must be performed on the in-
                                                                    out of each lot of cylinders.                             side of each container before closing
                                                                      (2) Specimens must conform to the                       and externally on each finished con-
                                                                    following:                                                tainer after heat treatment. Evidence
                                                                      (i) A gauge length of at least 24 times                 of discontinuities, which in the opinion
                                                                    the thickness with a width not over six                   of a qualified inspector may appre-
                                                                    times the thickness. The specimen, ex-                    ciably weaken or decrease the dura-
                                                                    clusive of grip ends, may not be flat-                    bility of the cylinder, must be cause for
                                                                    tened. Grip ends may be flattened to                      rejection.
                                                                    within one inch of each end of the re-                       (o) Leakage test. All spun cylinders
                                                                    duced section. When size of cylinder                      and plugged cylinders must be tested
                                                                    does not permit securing straight                         for leakage by dry gas or dry air pres-
                                                                    specimens, the specimens may be                           sure after the bottom has been cleaned
                                                                    taken in any location or direction and                    and is free from all moisture, subject
                                                                    may be straightened or flattened cold                     to the following conditions and limita-
                                                                    by pressure only, not by blows. When                      tions:
                                                                    specimens are so taken and prepared,                         (1) Pressure, approximately the same
                                                                    the inspector’s report must show in                       as but not less than service pressure,
                                                                    connection with the record of physical                    must be applied to one side of the fin-
                                                                    tests detailed information in regard to                   ished bottom over an area of at least
                                                                    such specimens.                                           1⁄16 of the total area of the bottom but

                                                                      (ii) Heating of a specimen for any                      not less than 3⁄4 inch in diameter, in-
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                                                                    purpose is not authorized.                                cluding the closure, for at least one
                                                                      (3) The yield strength in tension                       minute, during which time the other
                                                                    must be the stress corresponding to a                     side of the bottom exposed to pressure

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                                                                    § 178.45                                                                      49 CFR Ch. I (10–1–09 Edition)

                                                                    must be covered with water and closely                    be permanent and legible. Stamping on
                                                                    examined for indications of leakage.                      side wall not authorized.
                                                                    Except as provided in paragraph (q) of                      (2) The rejection elastic expansion
                                                                    this section, a cylinder must be re-                      (REE), in cubic cm (cc), must be
                                                                    jected if there is leakage.                               marked on the cylinder near the date
                                                                      (2) A spun cylinder is one in which an                  of test. The REE for a cylinder is 1.05
                                                                    end closure in the finished cylinder has                  times its original elastic expansion.
                                                                    been welded by the spinning process.                        (3) Name plates are authorized, pro-
                                                                      (3) A plugged cylinder is one in which                  vided that they can be permanently
                                                                    a permanent closure in the bottom of a                    and securely attached to the cylinder.
                                                                    finished cylinder has been effected by a                  Attachment by either brazing or weld-
                                                                    plug.                                                     ing is not permitted. Attachment by
                                                                      (4) As a safety precaution, if the                      soldering is permitted provided steel
                                                                    manufacturer elects to make this test                     temperature does not exceed 500 °F.
                                                                                                                                (s) Inspector’s report. In addition to
                                                                    before the hydrostatic test, the manu-
                                                                                                                              the requirements of § 178.35, the inspec-
                                                                    facturer should design the test appa-
                                                                                                                              tor’s report must indicate the rejection
                                                                    ratus so that the pressure is applied to
                                                                                                                              elastic expansion (REE), in cubic cm
                                                                    the smallest area practicable, around
                                                                                                                              (cc).
                                                                    the point of closure, and so as to use
                                                                    the smallest possible volume of air or                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    gas.                                                      amended at 62 FR 51561, Oct. 1, 1997; 65 FR
                                                                                                                              58631, Sept. 29, 2000; 66 FR 45385, Aug. 28, 2001;
                                                                      (p) Acceptable results of tests. Results
                                                                                                                              67 FR 51652, Aug. 8, 2002; 68 FR 75748, 75749,
                                                                    of the flattening test, physical tests,                   Dec. 31, 2003]
                                                                    burst test, and cycling test must con-
                                                                    form to the following:                                    § 178.45 Specification 3T seamless steel
                                                                      (1) Flattening required without                              cylinder.
                                                                    cracking to ten times the wall thick-                        (a) Type, size, and service pressure. A
                                                                    ness of the cylinder.                                     DOT 3T cylinder is a seamless steel
                                                                      (2) Physical tests:                                     cylinder with a minimum water capac-
                                                                      (i) An elongation of at least 6 percent                 ity of 1,000 pounds and a minimum
                                                                    for a gauge length of 24 times the wall                   service pressure of 1,800 psig. Each cyl-
                                                                    thickness.                                                inder must have integrally formed
                                                                      (ii) The tensile strength may not ex-                   heads concave to pressure at both ends.
                                                                    ceed 165,000 p.s.i.                                       The inside head shape must be hemi-
                                                                      (3) The burst pressure must be at                       spherical, ellipsoidal in which the
                                                                    least 4⁄3 times the test pressure.                        major axis is two times the minor axis,
                                                                      (4) Cycling-at least 10,000 pressuriza-                 or a dished shape falling within these
                                                                    tions.                                                    two limits. Permanent closures formed
                                                                      (q) Rejected cylinders. Reheat treat-                   by spinning are prohibited.
                                                                    ment is authorized for rejected cyl-                         (b) Material, steel. Only open hearth,
                                                                                                                              basic oxygen, or electric furnace proc-
                                                                    inders. Subsequent thereto, cylinders
                                                                                                                              ess steel of uniform quality is author-
                                                                    must pass all prescribed tests to be ac-
                                                                                                                              ized. The steel analysis must conform
                                                                    ceptable. Repair by welding or spinning
                                                                                                                              to the following:
                                                                    is not authorized. For each cylinder
                                                                    subjected to reheat treatment during                                             ANALYSIS TOLERANCES
                                                                    original manufacture, sidewall meas-
                                                                    urements must be made to verify that                                                                                     Check Analysis
                                                                                                                                        Element                    Ladle analysis
                                                                    the minimum sidewall thickness meets                                                                                     Under          Over
                                                                    specification requirements after the
                                                                                                                              Carbon ........................     0.35 to 0.50 ......             0.03       0.04
                                                                    final heat treatment.                                     Manganese .................         0.75 to 1.05 ......             0.04       0.04
                                                                      (r) Marking. (1) Cylinders must be                      Phosphorus (max) ......             0.035 .................    ............    0.01
                                                                    marked by low stress type steel stamp-                    Sulphur (max) .............         0.04 ...................   ............    0.01
                                                                                                                              Silicon .........................   0.15 to 0.35 ......             0.02       0.03
                                                                    ing in an area and to a depth which                       Chromium ...................        0.80 to 1.15 ......             0.05       0.05
                                                                    will insure that the wall thickness                       Molybdenum ...............          0.15 to 0.25 ......             0.02       0.02
                                                                    measured from the root of the stamp-
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                                                                    ing to the interior surface is equal to                     (1) A heat of steel made under the
                                                                    or greater than the minimum pre-                          specifications in the table in this para-
                                                                    scribed wall thickness. Stamping must                     graph (b), the ladle analysis of which is

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.45

                                                                    slightly out of the specified range, is                   thickness must be increased when nec-
                                                                    acceptable if satisfactory in all other                   essary to meet this additional require-
                                                                    aspects. However, the check analysis                      ment:
                                                                    tolerances shown in the table in this                       (i) The sum of two times the max-
                                                                    paragraph (b) may not be exceeded ex-                     imum tensile stress in the bottom fi-
                                                                    cept as approved by the Department.                       bers due to bending (see paragraph
                                                                      (2) Material with seams, cracks, lam-                   (d)(2)(ii) of this section), plus the max-
                                                                    inations, or other injurious defects is                   imum tensile stress in the same fibers
                                                                    not permitted.                                            due to hydrostatic testing (see para-
                                                                      (3) Material used must be identified                    graph (d)(2)(iii) of this section) may
                                                                    by any suitable method.                                   not exceed 80 percent of the minimum
                                                                      (c) Manufacture. General manufac-                       yield strength of the steel at this max-
                                                                    turing requirements are as follows:                       imum stress.
                                                                      (1) Surface finish must be uniform                        (ii) The following formula must be
                                                                    and reasonably smooth.                                    used to calculate the maximum tensile
                                                                      (2) Inside surfaces must be clean, dry,                 stress due to bending:
                                                                    and free of loose particles.                              S = Mc / I
                                                                      (3) No defect of any kind is permitted
                                                                    if it is likely to weaken a finished cyl-                 Where:
                                                                    inder.                                                    S = Tensile stress in psi;
                                                                      (4) If the cylinder surface is not origi-               M = Bending moment in inch-pounds (wl2/8);
                                                                                                                              I = Moment of inertia—0.04909 (D4¥d4) in
                                                                    nally free from the defects, the surface
                                                                                                                                inches fourth;
                                                                    may be machined or otherwise treated                      c = Radius (D/2) of cylinder in inches;
                                                                    to eliminate these defects provided the                   w = Weight per inch of cylinder filled with
                                                                    minimum wall thickness is main-                             water;
                                                                    tained.                                                   l = Length of cylinder in inches;
                                                                      (5) Welding or brazing on a cylinder                    D = Outside diameter in inches;
                                                                    is not permitted.                                         d = Inside diameter in inches.
                                                                      (d) Wall thickness. The minimum wall                      (iii) The following formula must be
                                                                    thickness must be such that the wall                      used to calculate the maximum longi-
                                                                    stress at the minimum specified test                      tudinal tensile stress due to hydro-
                                                                    pressure does not exceed 67 percent of                    static test pressure:
                                                                    the minimum tensile strength of the
                                                                                                                              S = A1 P / A2
                                                                    steel as determined by the physical
                                                                    tests required in paragraphs (j) and (k)                  Where:
                                                                    of this section. A wall stress of more                    S = Tensile stress in psi;
                                                                    than 90,500 p.s.i. is not permitted. The                  A1 = Internal area in cross section of cyl-
                                                                    minimum wall thickness for any cyl-                         inder in square inches;
                                                                    inder may not be less than 0.225 inch.                    P = Hydrostatic test pressure-psig;
                                                                      (1) Calculation of the stress for cyl-                  A2 = Area of metal in cross section of cyl-
                                                                    inders must be made by the following                        inder in square inches.
                                                                    formula:                                                    (e) Heat treatment. Each completed
                                                                    S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)                        cylinder must be uniformly and prop-
                                                                                                                              erly heat treated prior to testing, as
                                                                    Where:                                                    follows:
                                                                    S = Wall stress in psi;                                     (1) Each cylinder must be heated and
                                                                    P = Minimum test pressure, at least 5⁄3 serv-             held at the proper temperature for at
                                                                      ice pressure;                                           least one hour per inch of thickness
                                                                    D = Outside diameter in inches;                           based on the maximum thickness of
                                                                    d = Inside diameter in inches.
                                                                                                                              the cylinder and then quenched in a
                                                                      (2) Each cylinder must meet the fol-                    suitable liquid medium having a cool-
                                                                    lowing additional requirement which                       ing rate not in excess of 80 percent of
                                                                    assumes a cylinder horizontally sup-                      water. The steel temperature on
                                                                    ported at its two ends and uniformly                      quenching must be that recommended
                                                                    loaded over its entire length. This load                  for the steel analysis, but it must
                                                                    consists of the weight per inch of                        never exceed 1750 °F.
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                                                                    length of the straight cylindrical por-                     (2) After quenching, each cylinder
                                                                    tion filled with water compressed to                      must be reheated to a temperature
                                                                    the specified test pressure. The wall                     below the transformation range but

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                                                                    § 178.45                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    not less than 1050 °F., and must be held                  pansion of the cylinder. In no case may
                                                                    at this temperature for at least one                      the pressure be held less than 30 sec-
                                                                    hour per inch of thickness based on the                   onds.
                                                                    maximum thickness of the cylinder.                          (4) If, due to failure of the test appa-
                                                                    Each cylinder must then be cooled                         ratus, the required test pressure can-
                                                                    under conditions recommended for the                      not be maintained, the test must be re-
                                                                    steel.                                                    peated at a pressure increased by 10
                                                                      (f) Openings. Openings in cylinders                     percent or 100 psig, whichever is lower
                                                                    must comply with the following:                           or, the cylinder must be reheat treated.
                                                                      (1) Openings are permitted on heads                       (5) Permanent volumetric expansion
                                                                    only.                                                     of the cylinder may not exceed 10 per-
                                                                      (2) The size of any centered opening                    cent of its total volumetric expansion
                                                                    in a head may not exceed one half the                     at the required test pressure.
                                                                    outside diameter of the cylinder.                           (6) Each cylinder must be tested to at
                                                                      (3) Openings in a head must have lig-                   least 5⁄3 times its service pressure.
                                                                    aments between openings of at least                         (h) Ultrasonic examination. After the
                                                                    three times the average of their hole                     hydrostatic test, the cylindrical sec-
                                                                    diameter. No off-center opening may                       tion of each vessel must be examined in
                                                                    exceed 2.625 inches in diameter.                          accordance with ASTM E 213 for shear
                                                                      (4) All openings must be circular.                      wave and E 114 for straight beam (IBR,
                                                                      (5) All openings must be threaded.                      Standard see § 171.7 of this subchapter).
                                                                    Threads must be in compliance with                        The equipment used must be calibrated
                                                                    the following:                                            to detect a notch equal to five percent
                                                                      (i) Each thread must be clean cut,                      of the design minimum wall thickness.
                                                                    even, without any checks, and to                          Any discontinuity indication greater
                                                                    gauge.                                                    than that produced by the five percent
                                                                      (ii) Taper threads, when used, must                     notch must be cause for rejection of
                                                                    be the American Standard Pipe thread                      the cylinder, unless the discontinuity
                                                                    (NPT) type and must be in compliance                      is repaired within the requirements of
                                                                    with the requirements of NBS Hand-                        this specification.
                                                                    book H–28 (IBR, see § 171.7 of this sub-                    (i) Basic requirements for tension and
                                                                    chapter).                                                 Charpy impact tests. Cylinders must be
                                                                      (iii) Taper threads conforming to Na-                   subjected to a tension and Charpy im-
                                                                    tional Gas Taper thread (NGT) stand-                      pact as follows:
                                                                    ards must be in compliance with the                         (1) When the cylinders are heat treat-
                                                                    requirements of NBS Handbook H–28.                        ed in a batch furnace, two tension
                                                                      (iv) Straight threads conforming                        specimens and three Charpy impact
                                                                    with National Gas Straight thread                         specimens must be tested from one of
                                                                    (NGS) standards are authorized. These                     the cylinders or a test ring from each
                                                                    threads must be in compliance with the                    batch. The lot size represented by these
                                                                    requirements of NBS Handbook H–28.                        tests may not exceed 200 cylinders.
                                                                      (g) Hydrostatic test. Each cylinder                       (2) When the cylinders are heat treat-
                                                                    must be tested at an internal pressure                    ed in a continuous furnace, two tension
                                                                    by the water jacket method or other                       specimens and three Charpy impact
                                                                    suitable method, conforming to the fol-                   specimens must be tested from one of
                                                                    lowing requirements:                                      the cylinders or a test ring from each
                                                                      (1) The testing apparatus must be op-                   four hours or less of production. How-
                                                                    erated in a manner that will obtain ac-                   ever, in no case may a test lot based on
                                                                    curate data. Any pressure gauge used                      this production period exceed 200 cyl-
                                                                    must permit reading to an accuracy of                     inders.
                                                                    one percent. Any expansion gauge used                       (3) Each specimen for the tension and
                                                                    must permit reading of the total ex-                      Charpy impact tests must be taken
                                                                    pansion to an accuracy of one percent.                    from the side wall of a cylinder or from
                                                                      (2) Any internal pressure applied to                    a ring which has been heat treated
                                                                    the cylinder after heat treatment and                     with the finished cylinders of which
                                                                    before the official test may not exceed                   the specimens must be representative.
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                                                                    90 percent of the test pressure.                          The axis of the specimens must be par-
                                                                      (3) The pressure must be maintained                     allel to the axis of the cylinder. Each
                                                                    sufficiently long to assure complete ex-                  cylinder or ring specimen for test must

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                                      § 178.45

                                                                    be of the same diameter, thickness, and                   accuracy of this method is question-
                                                                    metal as the finished cylinders they                      able the entire stress-strain diagram
                                                                    represent. A test ring must be at least                   must be plotted and the yield strength
                                                                    24 inches long with ends covered during                   determined from the 0.2 percent offset.
                                                                    the heat treatment process so as to                         (iii) For the purpose of strain meas-
                                                                    simulate the heat treatment process of                    urement, the initial strain must be set
                                                                    the finished cylinders it represents.                     with the specimen under a stress of
                                                                       (4) A test cylinder or test ring need                  12,000 p.s.i. and the strain indicator
                                                                    represent only one of the heats in a                      reading set at the calculated cor-
                                                                    furnace batch provided the other heats                    responding strain.
                                                                    in the batch have previously been test-                     (iv) The cross-head speed of the test-
                                                                    ed and have passed the tests and that                     ing machine may not exceed 1⁄8 inch per
                                                                    such tests do not represent more than
                                                                                                                              minute during the determination of
                                                                    200 cylinders from any one heat.
                                                                                                                              yield strength.
                                                                       (5) The test results must conform to
                                                                    the requirements specified in para-                         (4) Each impact specimen must be
                                                                    graphs (j) and (k) of this section.                       Charpy V-notch type size 10 mm × 10
                                                                       (6) When the test results do not con-                  mm taken in accordance with para-
                                                                    form to the requirements specified, the                   graph 11 of ASTM A 333 (IBR, see § 171.7
                                                                    cylinders represented by the tests may                    of this subchapter). When a reduced
                                                                    be reheat treated and the tests re-                       size specimen is used, it must be the
                                                                    peated. Paragraph (i)(5) of this section                  largest size obtainable.
                                                                    applies to any retesting.                                   (k) Acceptable physical test results. Re-
                                                                       (j) Basic conditions for acceptable phys-              sults of physical tests must conform to
                                                                    ical testing. The following criteria must                 the following:
                                                                    be followed to obtain acceptable phys-                      (1) The tensile strength may not ex-
                                                                    ical test results:                                        ceed 155,000 p.s.i.
                                                                       (1) Each tension specimen must have                      (2) The elongation must be at least 16
                                                                    a gauge length of two inches with a                       percent for a two-inch gage length.
                                                                    width not exceeding one and one-half                        (3) The Charpy V-notch impact prop-
                                                                    inches. Except for the grip ends, the                     erties for the three impact specimens
                                                                    specimen may not be flattened. The                        which must be tested at 0 °F may not
                                                                    grip ends may be flattened to within                      be less than the values shown as fol-
                                                                    one inch of each end of the reduced sec-                  lows:
                                                                    tion.
                                                                       (2) A specimen may not be heated                        Size of specimen             Average value              Minimum value
                                                                                                                                                            for acceptance            (1 specimen only
                                                                    after heat treatment specified in para-                          (mm)                    (3 specimens)                of the 3)
                                                                    graph (d) of this section.
                                                                       (3) The yield strength in tension                      10.0×10.0 ..............    25.0 ft. lbs. ...........   20.0 ft. lbs.
                                                                                                                              10.0×7.5 ................   21.0 ft. lbs. ...........   17.0 ft. lbs.
                                                                    must be the stress corresponding to a
                                                                                                                              10.0×5.0 ................   17.0 ft. lbs. ...........   14.0 ft. lbs.
                                                                    permanent strain of 0.2 percent of the
                                                                    gage length.
                                                                                                                                (4) After the final heat treatment,
                                                                       (i) This yield strength must be deter-
                                                                    mined by the ‘‘offset’’ method or the                     each vessel must be hardness tested on
                                                                    ‘‘extension under load’’ method de-                       the cylindrical section. The tensile
                                                                    scribed in ASTM E 8 (IBR, see § 171.7 of                  strength equivalent of the hardness
                                                                    this subchapter).                                         number obtained may not be more than
                                                                       (ii) For the ‘‘extension under load’’                  165,000 p.s.i. (Rc 36). When the result of
                                                                    method, the total strain (or extension                    a hardness test exceeds the maximum
                                                                    under load) corresponding to the stress                   permitted, two or more retests may be
                                                                    at which the 0.2 percent permanent                        made; however, the hardness number
                                                                    strain occurs may be determined with                      obtained in each retest may not exceed
                                                                    sufficient accuracy by calculating the                    the maximum permitted.
                                                                    elastic extension of the gage length                        (l) Rejected cylinders. Reheat treat-
                                                                    under appropriate load and adding                         ment is authorized for rejected cyl-
                                                                    thereto 0.2 percent of the gage length.                   inders. However, each reheat treated
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                                                                    Elastic extension calculations must be                    cylinder must subsequently pass all the
                                                                    based on an elastic modulus of                            prescribed tests. Repair by welding is
                                                                    30,000,000. However, when the degree of                   not authorized.

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                                                                    § 178.46                                                                                                       49 CFR Ch. I (10–1–09 Edition)

                                                                      (m) Markings. Marking must be done                                                           ity of 1000 pounds and minimum service
                                                                    by stamping into the metal of the cyl-                                                         pressure of 150 psig.
                                                                    inder. All markings must be legible and                                                          (b) Authorized material and identifica-
                                                                    located on a shoulder.                                                                         tion of material. The material of con-
                                                                      (n) Inspector’s report. In addition to                                                       struction must meet the following con-
                                                                    the requirements of § 178.35, the inspec-                                                      ditions:
                                                                    tor’s report for the physical test re-                                                           (1) Starting stock must be cast stock
                                                                    port, must indicate the average value                                                          or traceable to cast stock.
                                                                    for three specimens and the minimum                                                              (2) Material with seams, cracks, lam-
                                                                    value for one specimen for each lot                                                            inations, or other defects likely to
                                                                    number.                                                                                        weaken the finished cylinder may not
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as                                                  be used.
                                                                    amended at 66 FR 45385, 43588, Aug. 28, 2001;                                                    (3) Material must be identified by a
                                                                    67 FR 51652, Aug. 8, 2002; 68 FR 48571, Aug. 14,                                               suitable method that will identify the
                                                                    2003; 68 FR 75748, 75749, Dec. 31, 2003]                                                       alloy, the aluminum producer’s cast
                                                                                                                                                                   number, the solution heat treat batch
                                                                    § 178.46 Specification 3AL seamless                                                            number and the lot number.
                                                                         aluminum cylinders.                                                                         (4) The material must be of uniform
                                                                       (a) Size and service pressure. A DOT                                                        quality. Only the following heat treat-
                                                                    3AL cylinder is a seamless aluminum                                                            able aluminum alloys in table 1 and 2
                                                                    cylinder with a maximum water capac-                                                           are permitted as follows:
                                                                     TABLE 1—HEAT OR CAST ANALYSIS FOR ALUMINUM; SIMILAR TO ‘‘ALUMINUM ASSOCIATION’’1 ALLOY
                                                                                                           6061
                                                                                                                              [CHEMICAL ANALYSIS IN WEIGHT PERCENT2]

                                                                                                                                                                                                              Other
                                                                       Si                                                          Mg
                                                                                     Fe            Cu               Mn                             Cr             Zn        Ti          Pb       Bi
                                                                      min/                                                         min/                                                                                        A1
                                                                                     max         min/max            max                         min/max           max      max          max     max      each         total
                                                                      max                                                          max                                                                   max          max

                                                                     0.4/0.8             0.7      0.15/0.4            0.15       0.8/1.2        0.04/0.35          0.25     0.15        0.005   0.005       0.05       0.15   Bal.
                                                                       1 The‘‘Aluminum Association’’ refers to ‘‘Aluminum Standards and Data 1993’’, published by the Aluminum Association Inc.
                                                                      2 Except for ‘‘Pb’’ and ‘‘Bi’’, the chemical composition corresponds with that of Table 1 of ASTM B 221 (IBR, see § 171.7 of this
                                                                    subchapter) for Aluminum Association alloy 6061.

                                                                                                                            TABLE 2—MECHANICAL PROPERTY LIMITS
                                                                                                                                                                          Tensile strength—PSI               Elongation—percent
                                                                                                    Alloy and temper                                                                                          minimum for 2″ or
                                                                                                                                                                 Ultimate—minimum        Yield—minimum       4D 1 size specimen

                                                                    6061–T6 ..................................................................................              38,000                 35,000                       214

                                                                       1 ‘‘D’’
                                                                            represents specimen diameters. When the cylinder wall is greater than ⁄ inch thick, a retest without reheat treatment
                                                                                                                                                                                 3 16

                                                                    using the 4D size specimen is authorized if the test using the 2 inch size specimen fails to meet elongation requirements.
                                                                      2 When cylinder wall is not over 3⁄16-inch thick, 10 percent elongation is authorized when using a 24t×6t size test specimen.




                                                                      (5) All starting stock must be 100 per-                                                      through (b)(6) of this section must be
                                                                    cent ultrasonically inspected, along                                                           rejected.
                                                                    the length at right angles to the cen-                                                           (c) Manufacture. Cylinders must be
                                                                    tral axis from two positions at 90° to                                                         manufactured in accordance with the
                                                                    one another. The equipment and con-                                                            following requirements:
                                                                    tinuous scanning procedure must be ca-                                                           (1) Cylinder shells must be manufac-
                                                                    pable of detecting and rejecting inter-                                                        tured by the backward extrusion meth-
                                                                    nal defects such as cracks which have                                                          od and have a cleanliness level ade-
                                                                    an ultrasonic response greater than                                                            quate to ensure proper inspection. No
                                                                    that of a calibration block with a 5⁄64-
                                                                                                                                                                   fissure or other defect is acceptable
                                                                    inch diameter flat bottomed hole.
                                                                                                                                                                   that is likely to weaken the finished
                                                                      (6) Cast stock must have uniform
                                                                                                                                                                   cylinder below the design strength re-
                                                                    equiaxed grain structure not to exceed
                                                                                                                                                                   quirements. A reasonably smooth and
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                                                                    500 microns maximum.
                                                                      (7) Any starting stock not complying                                                         uniform surface finish is required. If
                                                                    with the provisions of paragraphs (b)(1)                                                       not originally free from such defects,

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.46

                                                                    the surface may be machined or other-                     ice pressure, or diameter; a 30 percent
                                                                    wise conditioned to eliminate these de-                   or greater change in water capacity or
                                                                    fects.                                                    base thickness; any change in material;
                                                                      (2) Thickness of the cylinder base                      over 100 percent increase in size of
                                                                    may not be less than the prescribed                       openings; or any change in the number
                                                                    minimum wall thickness of the cylin-                      of openings.
                                                                    drical shell. The cylinder base must                        (d) Wall thickness. The minimum wall
                                                                    have a basic torispherical, hemi-                         thickness must be such that the wall
                                                                    spherical, or ellipsoidal interior base                   stress at the minimum specified test
                                                                    configuration where the dish radius is                    pressure will not exceed 80 percent of
                                                                    no greater than 1.2 times the inside di-                  the minimum yield strength nor exceed
                                                                    ameter of the shell. The knuckle radius                   67 percent of the minimum ultimate
                                                                    may not be less than 12 percent of the                    tensile strength as verified by physical
                                                                    inside diameter of the shell. The inte-                   tests in paragraph (i) of this section.
                                                                    rior base contour may deviate from the                    The minimum wall thickness for any
                                                                    true torispherical, hemispherical or el-                  cylinder with an outside diameter
                                                                    lipsoidal configuration provided that—                    greater than 5 inches must be 0.125
                                                                      (i) Any areas of deviation are accom-                   inch. Calculations must be made by the
                                                                    panied by an increase in base thick-                      following formula:
                                                                    ness;
                                                                                                                              S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)
                                                                      (ii) All radii of merging surfaces are
                                                                    equal to or greater than the knuckle                      Where:
                                                                    radius;                                                   S = Wall stress in psi;
                                                                      (iii) Each design has been qualified                    P = Prescribed minimum test pressure in
                                                                    by successfully passing the cycling                         psig (see paragraph (g) of this section);
                                                                    tests in this paragraph (c); and                          D = Outside diameter in inches; and
                                                                      (iv) Detailed specifications of the                     d = Inside diameter in inches.
                                                                    base design are available to the inspec-                     (e) Openings. Openings must comply
                                                                    tor.                                                      with the following requirements:
                                                                      (3) For free standing cylinders, the
                                                                                                                                 (1) Openings are permitted in heads
                                                                    base thickness must be at least two
                                                                                                                              only.
                                                                    times the minimum wall thickness
                                                                                                                                 (2) The size of any centered opening
                                                                    along the line of contact between the
                                                                                                                              in a head may not exceed one-half the
                                                                    cylinder base and the floor when the
                                                                                                                              outside diameter of the cylinder.
                                                                    cylinders are in the vertical position.
                                                                      (4) Welding or brazing is prohibited.                      (3) Other openings are permitted in
                                                                      (5) Each new design and any signifi-                    the head of a cylinder if:
                                                                    cant change to any acceptable design                         (i) Each opening does not exceed 2.625
                                                                    must be qualified for production by                       inches in diameter, or one-half the out-
                                                                    testing prototype samples as follows:                     side diameter of the cylinder; which-
                                                                      (i) Three samples must be subjected                     ever is less;
                                                                    to 100,000 pressure reversal cycles be-                      (ii) Each opening is separated from
                                                                    tween zero and service pressure or                        each other by a ligament; and
                                                                    10,000 pressure reversal cycles between                      (iii) Each ligament which separates
                                                                    zero and test pressure, at a rate not in                  two openings must be at least three
                                                                    excess of 10 cycles per minute without                    times the average of the diameters of
                                                                    failure.                                                  the two openings.
                                                                      (ii) Three samples must be pressur-                        (4) All openings must be circular.
                                                                    ized to destruction and failure may not                      (5) All openings must be threaded.
                                                                    occur at less than 2.5 times the marked                   Threads must comply with the fol-
                                                                    cylinder service pressure. Each cyl-                      lowing:
                                                                    inder must remain in one piece. Fail-                        (i) Each thread must be clean cut,
                                                                    ure must initiate in the cylinder side-                   even, without checks, and to gauge.
                                                                    wall in a longitudinal direction. Rate                       (ii) Taper threads, when used, must
                                                                    of pressurization may not exceed 200                      conform to one of the following:
                                                                    psig per second.                                             (A) American Standard Pipe Thread
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                                                                      (6) In this specification ‘‘significant                 (NPT) type, conforming to the require-
                                                                    change’’ means a 10 percent or greater                    ments of NBS Handbook H–28 (IBR, see
                                                                    change in cylinder wall thickness, serv-                  § 171.7 of this subchapter);

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                                                                    § 178.46                                                                      49 CFR Ch. I (10–1–09 Edition)

                                                                      (B) National Gas Taper Thread (NGT)                     whichever is lower. If the test appa-
                                                                    type, conforming to the requirements                      ratus again fails to maintain the test
                                                                    of NBS Handbook H–28; or                                  pressure, the cylinder being tested
                                                                      (C) Other taper threads conforming                      must be rejected. Any internal pressure
                                                                    to other standards may be used pro-                       applied to the cylinder before any offi-
                                                                    vided the length is not less than that                    cial test may not exceed 90 percent of
                                                                    specified for NPT threads.                                the test pressure.
                                                                      (iii) Straight threads, when used,                        (3) The minimum test pressure is the
                                                                    must conform to one of the following:                     greatest of the following:
                                                                      (A) National Gas Straight Thread                          (i) 450 psig regardless of service pres-
                                                                    (NGS) type, conforming to the require-                    sure;
                                                                    ments of NBS Handbook H–28;                                 (ii) Two times the service pressure
                                                                      (B) Unified Thread (UN) type, con-                      for cylinders having service pressure
                                                                    forming to the requirements of NBS                        less than 500 psig; or
                                                                    Handbook H–28;                                              (iii) Five-thirds times the service
                                                                      (C) Controlled Radius Root Thread                       pressure for cylinders having a service
                                                                    (UN) type, conforming to the require-                     pressure of at least 500 psig.
                                                                    ments of NBS Handbook H–28; or                              (4) Permanent volumetric expansion
                                                                      (D) Other straight threads con-                         may not exceed 10 percent of total vol-
                                                                    forming to other recognized standards                     umetric expansion at test pressure.
                                                                    may be used provided that the require-                      (h) Flattening test. One cylinder taken
                                                                    ments in paragraph (e)(5)(iv) of this                     at random out of each lot must be sub-
                                                                    section are met.                                          jected to a flattening test as follows:
                                                                      (iv) All straight threads must have at                    (1) The test must be between knife
                                                                    least 6 engaged threads, a tight fit, and                 edges, wedge shaped, having a 60° in-
                                                                    a factor of safety in shear of at least 10                cluded angle, and rounded in accord-
                                                                    at the test pressure of the cylinder.                     ance with the following table. The lon-
                                                                    Shear stress must be calculated by                        gitudinal axis of the cylinder must be
                                                                    using the appropriate thread shear area                   at an angle 90° to the knife edges dur-
                                                                    in accordance with NBS Handbook H–                        ing the test. The flattening test table
                                                                    28.                                                       is as follows:
                                                                      (f) Heat treatment. Prior to any test,                              TABLE 3—FLATTENING TEST TABLE
                                                                    all cylinders must be subjected to a so-
                                                                    lution heat treatment and aging treat-                                                                                                 Radius
                                                                                                                                           Cylinder wall thickness in inches                                  in
                                                                    ment appropriate for the aluminum                                                                                                      inches
                                                                    alloy used.
                                                                      (g) Hydrostatic test. Each cylinder                     Under .150 ...............................................................      .500
                                                                                                                              .150 to .249 .............................................................      .875
                                                                    must be subjected to an internal test                     .250 to .349 .............................................................     1.500
                                                                    pressure using the water jacket equip-                    .350 to .449 .............................................................     2.125
                                                                    ment and method or other suitable                         .450 to .549 .............................................................     2.750
                                                                                                                              .550 to .649 .............................................................     3.500
                                                                    equipment and method and comply                           .650 to .749 .............................................................     4.125
                                                                    with the following requirements:
                                                                      (1) The testing apparatus must be op-                     (2) An alternate bend test in accord-
                                                                    erated in a manner so as to obtain ac-                    ance with ASTM E 290 using a mandrel
                                                                    curate data. The pressure gauge used                      diameter not more than 6 times the
                                                                    must permit reading to an accuracy of                     wall thickness is authorized to qualify
                                                                    one percent. The expansion gauge must                     lots that fail the flattening test of this
                                                                    permit reading the total expansion to                     section without reheat treatment. If
                                                                    an accuracy of either one percent or 0.1                  used, this test must be performed on
                                                                    cubic centimeter.                                         two samples from one cylinder taken
                                                                      (2) The test pressure must be main-                     at random out of each lot of 200 cyl-
                                                                    tained for a sufficient period of time to                 inders or less.
                                                                    assure complete expansion of the cyl-                       (3) Each test cylinder must withstand
                                                                    inder. In no case may the pressure be                     flattening to nine times the wall thick-
                                                                    held less than 30 seconds. If, due to fail-               ness without cracking. When the alter-
                                                                    ure of the test apparatus, the required                   nate bend test is used, the test speci-
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                                                                    test pressure cannot be maintained,                       mens must remain uncracked when
                                                                    the test may be repeated at a pressure                    bent inward around a mandrel in the
                                                                    increased by 10 percent or 100 psig,                      direction of curvature of the cylinder

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.46

                                                                    wall until the interior edges are at a                    strength determined from the 0.2 per-
                                                                    distance apart not greater than the di-                   cent offset.
                                                                    ameter of the mandrel.                                      (iii) For the purpose of strain meas-
                                                                       (i) Mechanical properties test. Two test               urement, the initial strain must be set
                                                                    specimens cut from one cylinder rep-                      while the specimen is under a stress of
                                                                    resenting each lot of 200 cylinders or                    6,000 psi, the strain indicator reading
                                                                    less must be subjected to the mechan-                     being set at the calculated cor-
                                                                    ical properties test, as follows:                         responding strain.
                                                                       (1) The results of the test must con-                    (iv) Cross-head speed of the testing
                                                                    form to at least the minimum accept-                      machine may not exceed 1⁄8 inch per
                                                                    able mechanical property limits for                       minute during yield strength deter-
                                                                    aluminum alloys as specified in para-                     mination.
                                                                    graph (b) of this section.                                  (j) Rejected cylinder. Reheat treat-
                                                                       (2) Specimens must be 4D bar or                        ment of rejected cylinders is author-
                                                                    gauge length 2 inches with width not                      ized one time. Subsequent thereto, cyl-
                                                                    over 11⁄2 inch taken in the direction of                  inders must pass all prescribed tests to
                                                                    extrusion approximately 180° from each                    be acceptable.
                                                                    other; provided that gauge length at                        (k) Duties of inspector. In addition to
                                                                    least 24 times thickness with width not                   the requirements of § 178.35, the inspec-
                                                                                                                              tor shall:
                                                                    over 6 times thickness is authorized,
                                                                                                                                (1) Verify compliance with the provi-
                                                                    when cylinder wall is not over 3⁄16 inch
                                                                                                                              sions of paragraph (b) of this section
                                                                    thick. The specimen, exclusive of grip
                                                                                                                              by:
                                                                    ends, may not be flattened. Grip ends
                                                                                                                                (i) Performing or witnessing the per-
                                                                    may be flattened to within one inch of
                                                                                                                              formance of the chemical analyses on
                                                                    each end of the reduced section. When
                                                                                                                              each melt or cast lot or other unit of
                                                                    the size of the cylinder does not permit
                                                                                                                              starting material; or
                                                                    securing straight specimens, the speci-
                                                                                                                                (ii) Obtaining a certified chemical
                                                                    mens may be taken in any location or
                                                                                                                              analysis from the material or cylinder
                                                                    direction and may be straightened or
                                                                                                                              manufacturer for each melt, or cast of
                                                                    flattened cold by pressure only, not by
                                                                                                                              material; or
                                                                    blows. When such specimens are used,                        (iii) Obtaining a certified check anal-
                                                                    the inspector’s report must show that                     ysis on one cylinder out of each lot of
                                                                    the specimens were so taken and pre-                      200 cylinders or less, if a certificate
                                                                    pared. Heating of specimens for any                       containing data to indicate compliance
                                                                    purpose is forbidden.                                     with the material specification is ob-
                                                                       (3) The yield strength in tension                      tained.
                                                                    must be the stress corresponding to a                       (2) The inspector shall verify ultra-
                                                                    permanent strain of 0.2 percent of the                    sonic inspection of all material by in-
                                                                    gauge length.                                             spection or by obtaining the material
                                                                       (i) The yield strength must be deter-                  producer’s certificate of ultrasonic in-
                                                                    mined by either the ‘‘offset’’ method or                  spection. Ultrasonic inspection must be
                                                                    the ‘‘extension under load’’ method as                    performed or verified as having been
                                                                    prescribed in ASTM B 557 (IBR, see                        performed in accordance with para-
                                                                    § 171.7 of this subchapter).                              graph (c) of this section.
                                                                       (ii) In using the ‘‘extension under                      (3) The inspector must also deter-
                                                                    load’’ method, the total strain (or ‘‘ex-                 mine that each cylinder complies with
                                                                    tension under load’’) corresponding to                    this specification by:
                                                                    the stress at which the 0.2 percent per-                    (i) Selecting the samples for check
                                                                    manent strain occurs may be deter-                        analyses performed by other than the
                                                                    mined with sufficient accuracy by cal-                    material producer;
                                                                    culating the elastic extension of the                       (ii) Verifying that the prescribed
                                                                    gauge length under appropriate load                       minimum thickness was met by meas-
                                                                    and adding thereto 0.2 percent of the                     uring or witnessing the measurement
                                                                    gauge length. Elastic extension cal-                      of the wall thickness; and
                                                                    culations must be based on an elastic                       (iii) Verifying that the identification
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                                                                    modulus of 10,000,000 psi. In the event                   of material is proper.
                                                                    of controversy, the entire stress-strain                    (4) Prior to initial production of any
                                                                    diagram must be plotted and the yield                     design or design change, verify that the

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                                                                    § 178.47                                                                                                                 49 CFR Ch. I (10–1–09 Edition)

                                                                    design qualification tests prescribed in                                                           cable element used in the construction
                                                                    paragraph (c)(6) of this section have                                                              of the cylinder.
                                                                    been performed with acceptable re-                                                                 [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    sults.                                                                                             amended at 66 FR 45386–45388, Aug. 28, 2001; 67
                                                                      (l) Definitions. (1) In this specifica-                                                          FR 51652, Aug. 8, 2002; 68 FR 75749, Dec. 31,
                                                                    tion, a ‘‘lot’’ means a group of cyl-                                                              2003]
                                                                    inders successively produced having
                                                                                                                                                                       § 178.47 Specification       4DS    welded
                                                                    the same:                                                                                               stainless steel cylinders for aircraft
                                                                      (i) Size and configuration;                                                                           use.
                                                                      (ii) Specified material of construc-
                                                                                                                                                                          (a) Type, size, and service pressure. A
                                                                    tion;                                                                                              DOT 4DS cylinder is either a welded
                                                                      (iii) Process of manufacture and heat                                                            stainless steel sphere (two seamless
                                                                    treatment;                                                                                         hemispheres)       or    circumferentially
                                                                      (iv) Equipment of manufacture and                                                                welded cylinder both with a water ca-
                                                                    heat treatment; and                                                                                pacity of not over 100 pounds and a
                                                                      (v) Conditions of time, temperature                                                              service pressure of at least 500 but not
                                                                    and atmosphere during heat treatment.                                                              over 900 psig.
                                                                      (2) In no case may the lot size exceed                                                              (b) Steel. Types 304, 321 and 347 stain-
                                                                    200 cylinders, but any cylinder proc-                                                              less steel are authorized with proper
                                                                    essed for use in the required destruc-                                                             welding procedure. A heat of steel
                                                                    tive physical testing need not be count-                                                           made under the specifications in table
                                                                    ed as being one of the 200.                                                                        1 in this paragraph (b), check chemical
                                                                      (m) Inspector’s report. In addition to                                                           analysis of which is slightly out of the
                                                                    the information required by § 178.35, the                                                          specified range, is acceptable, if satis-
                                                                    record of chemical analyses must also                                                              factory in all other respects, provided
                                                                                                                                                                       the tolerances shown in table 2 in this
                                                                    include the alloy designation, and ap-
                                                                                                                                                                       paragraph (b) are not exceeded, except
                                                                    plicable information on iron, titanium,
                                                                                                                                                                       as approved by Associate Adminis-
                                                                    zinc, magnesium and any other appli-                                                               trator. The following chemical anal-
                                                                                                                                                                       yses are authorized:
                                                                                                                                     TABLE 1—AUTHORIZED MATERIALS
                                                                                                                                                                                             Stainless steels

                                                                                                                                                            304 (percent)                                 321 (percent)                           347 (percent)

                                                                    Carbon (max) .......................................................         0.08                                          0.08                                           0.08
                                                                    Manganese (max) ................................................             2.00                                          2.00                                           2.00
                                                                    Phosphorus (max) ...............................................             .030                                          .030                                           .030
                                                                    Sulphur (max) ......................................................         .030                                          .030                                           .030
                                                                    Silicon (max) ........................................................       .75                                           .75                                            .75
                                                                    Nickel ...................................................................   8.0/11.0                                      9.0/13.0                                       9.0/13.0
                                                                    Chromium ............................................................        18.0/20.0                                     17.0/20.0                                      17.0/20.0
                                                                    Molybdenum
                                                                    Titanium ...............................................................                                                   (1)
                                                                    Columbium ...........................................................                                                                                                     (2)
                                                                       1 Titanium may not be more than 5C and not more than 0.60%.
                                                                       2 Columbium may not be less than 10C and not more than 1.0%.



                                                                                                                             TABLE 2—CHECK ANALYSIS TOLERANCES
                                                                                                                                                                                                                            Tolerance (percent) over
                                                                                                                                                                                                                             the maximum limit or
                                                                                                                                                                                                                            under the minimum limit
                                                                                            Element                                                Limit or maximum specified (percent)
                                                                                                                                                                                                                           Under min-               Over max-
                                                                                                                                                                                                                           imum limit               imum limit

                                                                    Carbon .....................................................     To 0.15 incl ......................................................................                0.01               0.01
                                                                    Manganese ..............................................         Over 1.15 to 2.50 incl .....................................................                       0.05               0.05
                                                                    Phosphorus1 ............................................         All ranges ........................................................................   ....................             .01
                                                                    Sulphur ....................................................     All ranges ........................................................................   ....................             .01
                                                                    Silicon ......................................................   Over 0.30 to 1.00 incl .....................................................                         .05               .05
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                                                                    Nickel .......................................................   Over 5.30 to 10.00 incl ....................................................                         .10               .10
                                                                                                                                     Over 10.00 to 14.00 incl ..................................................                          .15               .15
                                                                    Chromium ................................................        Over 15.00 to 20.00 incl ..................................................                          .20               .20


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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                                                                                § 178.47

                                                                                                               TABLE 2—CHECK ANALYSIS TOLERANCES—Continued
                                                                                                                                                                                                                         Tolerance (percent) over
                                                                                                                                                                                                                          the maximum limit or
                                                                                                                                                                                                                         under the minimum limit
                                                                                           Element                                               Limit or maximum specified (percent)
                                                                                                                                                                                                                         Under min-    Over max-
                                                                                                                                                                                                                         imum limit    imum limit

                                                                    Titanium ...................................................   All ranges ........................................................................           .05           .05
                                                                    Columbium ..............................................       All ranges ........................................................................           .05           .05
                                                                       1Rephosphorized           steels not subject to check analysis for phosphorus.



                                                                      (c) Identification of material. Materials                                                        extend a distance of 6 times wall thickness
                                                                    must be identified by any suitable                                                                 from center of weld);
                                                                    method.                                                                                          E = 1.0 (for all other areas).
                                                                      (d) Manufacture. Cylinders must be                                                              (2) Calculation for a cylinder must be
                                                                    manufactured using equipment and                                                                 made by the formula:
                                                                    processes adequate to ensure that each
                                                                    cylinder produced conforms to the re-                                                            S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)
                                                                    quirements of this subpart. No defect is                                                         Where:
                                                                    permitted that is likely to weaken the                                                           S = Wall stress in psi;
                                                                    finished cylinder appreciably, a reason-                                                         P = Test pressure prescribed for water jacket
                                                                    ably smooth and uniform surface finish                                                             test, i.e., at least two times service pres-
                                                                    is required. No abrupt change in wall                                                              sure, in psig;
                                                                    thickness is permitted. Welding proce-                                                           D = Outside diameter in inches;
                                                                                                                                                                     d = Inside diameter in inches.
                                                                    dures and operators must be qualified
                                                                    in accordance with CGA Pamphlet C–3                                                                (g) Heat treatment. The seamless
                                                                    (IBR, see § 171.7 of this subchapter). All                                                       hemispheres and cylinders may be
                                                                    seams of the sphere or cylinder must be                                                          stress relieved or annealed for forming.
                                                                    fusion welded. Seams must be of the                                                              Welded container must be stress re-
                                                                    butt type and means must be provided                                                             lieved at a temperature of 775 °F ±25°
                                                                    for accomplishing complete penetra-                                                              after process treatment and before hy-
                                                                    tion of the joint.                                                                               drostatic test.
                                                                      (e) Attachments. Attachments to the                                                              (h) Openings in container. Openings
                                                                    container are authorized by fusion                                                               must comply with the following:
                                                                    welding provided that such attach-                                                                 (1) Each opening in the container
                                                                    ments are made of weldable stainless                                                             must be provided with a fitting, boss or
                                                                    steel in accordance with paragraph (b)                                                           pad of weldable stainless steel securely
                                                                    of this section.                                                                                 attached to the container by fusion
                                                                      (f) Wall thickness. The minimum wall                                                           welding.
                                                                    thickness must be such that the wall                                                               (2) Attachments to a fitting, boss, or
                                                                    stress at the minimum specified test                                                             pad must be adequate to prevent leak-
                                                                    pressure may not be over 60,000 psig. A                                                          age. Threads must comply with the fol-
                                                                    minimum wall thickness of 0.040 inch is                                                          lowing:
                                                                    required for any diameter container.                                                               (i) Threads must be clean cut, even,
                                                                    Calculations must be made by the fol-                                                            without checks, and tapped to gauge.
                                                                    lowing formulas:                                                                                   (ii) Taper threads to be of length not
                                                                      (1) Calculation for sphere must be                                                             less than as specified for American
                                                                    made by the formula:                                                                             Standard taper pipe threads.
                                                                                                                                                                       (iii) Straight threads having at least
                                                                    S = PD / 4tE                                                                                     4 engaged threads, to have tight fit and
                                                                    Where:                                                                                           calculated shear strength at least 10
                                                                    S = Wall stress in psi;                                                                          times the test pressure of the con-
                                                                    P = Test pressure prescribed for water jacket                                                    tainer; gaskets required, adequate to
                                                                      test, i.e., at least two times service pres-                                                   prevent leakage.
                                                                      sure, in psig;                                                                                   (i) Process treatment. Each container
                                                                    D = Outside diameter in inches;
                                                                    t = Minimum wall thickness in inches;                                                            must be hydraulically pressurized in a
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                                                                    E = 0.85 (provides 85 percent weld efficiency                                                    water jacket to at least 100 percent,
                                                                      factor which must be applied in the girth                                                      but not more than 110 percent, of the
                                                                      weld area and heat zones which zone must                                                       test pressure and maintained at this

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                                                                    § 178.50                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    pressure for a minimum of 3 minutes.                      taken at random out of each lot of 200
                                                                    Total and permanent expansion must                        or less after the hydrostatic test. Any
                                                                    be recorded and included in the inspec-                   projecting appurtenances may be cut
                                                                    tor’s report.                                             off (by mechanical means only) prior to
                                                                      (j) Hydrostatic test. Each cylinder                     crushing.
                                                                    must successfully withstand a hydro-                        (2) For cylinders the test must be be-
                                                                    static test as follows:                                   tween knife edges, wedge shaped, 60°
                                                                      (1) The test must be by water-jacket,                   angle, rounded to 1⁄2-inch radius. Test
                                                                    operated so as to obtain accurate data.                   one cylinder taken at random out of
                                                                    The pressure gauge must permit read-                      each lot of 200 or less, after the hydro-
                                                                    ing to an accuracy of 1 percent. The ex-                  static test.
                                                                    pansion gauge must permit reading of                        (n) Acceptable results for flattening and
                                                                    total expansion to an accuracy either                     burst tests. Acceptable results for flat-
                                                                    of 1 percent or 0.1 cubic centimeter.                     tening and burst tests are as follows:
                                                                      (2) Pressure must be maintained for                       (1) Flattening required to 50 percent
                                                                    at least 30 seconds and sufficiently                      of the original outside diameter with-
                                                                    longer to ensure complete expansion.                      out cracking.
                                                                    If, due to failure of the test apparatus,                   (2) Burst pressure must be at least 3
                                                                    the test pressure cannot be main-                         times the service pressure.
                                                                    tained, the test may be repeated at a                       (o) Rejected containers. Repair of weld-
                                                                    pressure increased by 10 percent or 100                   ed seams by welding prior to process
                                                                    psig, whichever is the lower.                             treatment is authorized. Subsequent
                                                                      (3) Permanent volumetric expansion                      thereto, containers must be heat treat-
                                                                    may not exceed 10 percent of total vol-                   ed and pass all prescribed tests.
                                                                    umetric expansion at test pressure.                         (p) Duties of inspector. In addition to
                                                                      (4) Each container must be tested to                    the requirements of § 178.35, the inspec-
                                                                    at least 2 times service pressure.                        tor must verify that all tests are con-
                                                                      (5) Container must then be inspected.                   ducted at temperatures between 60 °F
                                                                    Any wall thickness lower than that re-                    and 90 °F.
                                                                    quired by paragraph (f) of this section                     (q) Marking. Markings must be
                                                                    must be cause for rejection. Bulges and                   stamped plainly and permanently on a
                                                                    cracks must be cause for rejection.                       permanent attachment or on a metal
                                                                    Welded joint defects exceeding require-                   nameplate permanently secured to the
                                                                    ments of paragraph (k) of this section                    container by means other than soft sol-
                                                                    must be cause for rejection.                              der.
                                                                      (k) Radiographic inspection. Radio-                     [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    graphic inspection is required on all                     amended at 66 FR 45386, 45388, Aug. 28, 2001;
                                                                    welded joints which are subjected to in-                  67 FR 51653, Aug. 8, 2002; 68 FR 75748, Dec. 31,
                                                                    ternal pressure, except that at the dis-                  2003]
                                                                    cretion of the disinterested inspector,
                                                                    openings less than 25 percent of the                      § 178.50 Specification 4B welded or
                                                                    container diameter need not be sub-                            brazed steel cylinders.
                                                                    jected to radiographic inspection. Evi-                      (a) Type, size, and service pressure. A
                                                                    dence of any defects likely to seriously                  DOT 4B is a welded or brazed steel cyl-
                                                                    weaken the container is cause for re-                     inder with longitudinal seams that are
                                                                    jection. Radiographic inspection must                     forged lap-welded or brazed and with
                                                                    be performed subsequent to the hydro-                     water capacity (nominal) not over 1,000
                                                                    static test.                                              pounds and a service pressure of at
                                                                      (l) Burst test. One container taken at                  least 150 but not over 500 psig. Cyl-
                                                                    random out of 200 or less must be                         inders closed in by spinning process are
                                                                    hydrostatically tested to destruction.                    not authorized.
                                                                    Rupture pressure must be included as                         (b) Steel. Open-hearth, electric or
                                                                    part of the inspector’s report.                           basic oxygen process steel of uniform
                                                                      (m) Flattening test. A flattening test                  quality must be used. Content percent
                                                                    must be performed as follows:                             may not exceed the following: Carbon,
                                                                      (1) For spheres the test must be at                     0.25; phosphorus, 0.045; sulphur, 0.050.
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                                                                    the weld between parallel steel plates                       (c) Identification of material. Material
                                                                    on a press with welded seam at right                      must be identified by any suitable
                                                                    angles to the plates. Test one sphere                     method except that plates and billets

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.50

                                                                    for hotdrawn cylinders must be marked                     of 4130X steel which may be used with
                                                                    with the heat number.                                     proper welding procedure.
                                                                      (d) Manufacture. Cylinders must be                        (f) Wall thickness. The wall thickness
                                                                    manufactured using equipment and                          of the cylinder must comply with the
                                                                    processes adequate to ensure that each                    following requirements:
                                                                    cylinder produced conforms to the re-                       (1) For cylinders with outside diame-
                                                                    quirements of this subpart. No defect is                  ters over 6 inches the minimum wall
                                                                    permitted that is likely to weaken the                    thickness must be 0.090 inch. In any
                                                                    finished cylinder appreciably. A rea-                     case, the minimum wall thickness
                                                                    sonably smooth and uniform surface                        must be such that calculated wall
                                                                    finish is required. Exposed bottom                        stress at minimum test pressure (para-
                                                                    welds on cylinders over 18 inches long                    graph (i)(4) of this section) may not ex-
                                                                    must be protected by footrings. Weld-                     ceed the following values:
                                                                    ing procedures and operators must be                        (i) 24,000 psi for cylinders without
                                                                    qualified in accordance with CGA Pam-                     longitudinal seam.
                                                                    phlet C–3 (IBR, see § 171.7 of this sub-                    (ii) 22,800 psig for cylinders having
                                                                    chapter). Seams must be made as fol-                      copper brazed or silver alloy brazed
                                                                    lows:                                                     longitudinal seam.
                                                                      (1) Welded or brazed circumferential                      (iii) 18,000 psi for cylinders having
                                                                    seams. Heads attached by brazing must                     forged lapped welded longitudinal
                                                                    have a driving fit with the shell, unless                 seam.
                                                                    the shell is crimped, swedged, or curled                    (2) Calculation must be made by the
                                                                    over the skirt or flange of the head,                     formula:
                                                                    and be thoroughly brazed until com-
                                                                                                                              S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)
                                                                    plete penetration by the brazing mate-
                                                                    rial of the brazed joint is secured.                      Where:
                                                                    Depth of brazing from end of shell must                   S = wall stress in psi;
                                                                    be at least four times the thickness of                   P = minimum test pressure prescribed for
                                                                    shell metal.                                                water jacket test or 450 psig whichever is
                                                                      (2) Longitudinal seams in shells. Longi-                  the greater;
                                                                    tudinal seams must be forged lap weld-                    D = outside diameter in inches;
                                                                                                                              d = inside diameter in inches.
                                                                    ed, by copper brazing, by copper alloy
                                                                    brazing, or by silver alloy brazing. Cop-                   (g) Heat treatment. Cylinder body and
                                                                    per alloy composition must be: Copper,                    heads, formed by drawing or pressing,
                                                                    95 percent minimum; Silicon, 1.5 per-                     must be uniformly and properly heat
                                                                    cent to 3.85 percent; Manganese, 0.25                     treated prior to tests.
                                                                    percent to 1.10 percent. The melting                        (h) Opening in cylinders. Openings in
                                                                    point of the silver alloy brazing mate-                   cylinders must conform to the fol-
                                                                    rial must be in excess of 1000 °F. When                   lowing:
                                                                    brazed, the plate edge must be lapped                       (1) Each opening in cylinders, except
                                                                    at least eight times the thickness of                     those for safety devices, must be pro-
                                                                    plate, laps being held in position, sub-                  vided with a fitting, boss, or pad, se-
                                                                    stantially metal to metal, by riveting                    curely attached to cylinder by brazing
                                                                    or electric spot-welding; brazing must                    or by welding or by threads. Fitting,
                                                                    be done by using a suitable flux and by                   boss, or pad must be of steel suitable
                                                                    placing brazing material on one side of                   for the method of attachment em-
                                                                    seam and applying heat until this ma-                     ployed, and which need not be identi-
                                                                    terial shows uniformly along the seam                     fied or verified as to analysis except
                                                                    of the other side.                                        that if attachment is by welding, car-
                                                                      (e) Welding or brazing. Only the at-                    bon content may not exceed 0.25 per-
                                                                    tachment of neckrings, footrings, han-                    cent. If threads are used, they must
                                                                    dles, bosses, pads, and valve protection                  comply with the following:
                                                                    rings to the tops and bottoms of cyl-                       (i) Threads must be clean cut, even
                                                                    inders by welding or brazing is author-                   without checks, and tapped to gauge.
                                                                    ized. Such attachments and the portion                      (ii) Taper threads to be of length not
                                                                    of the container to which they are at-                    less than as specified for American
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                                                                    tached must be made of weldable steel,                    Standard taper pipe threads.
                                                                    the carbon content of which may not                         (iii) Straight threads, having at least
                                                                    exceed 0.25 percent except in the case                    4 engaged threads, to have tight fit and

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                                                                    § 178.50                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    calculated shear strength at least 10                     less, flattening tests are authorized to
                                                                    times the test pressure of the cylinder;                  be made on a ring at least 8 inches long
                                                                    gaskets required, adequate to prevent                     cut from each cylinder and subjected to
                                                                    leakage.                                                  same heat treatment as the finished
                                                                      (iv) A brass fitting may be brazed to                   cylinder.
                                                                    the steel boss or flange on cylinders                       (k) Physical test. A physical test must
                                                                    used as component parts of hand fire                      be conducted to determine yield
                                                                    extinguishers.                                            strength, tensile strength, elongation,
                                                                      (2) The closure of a fitting, boss, or                  and reduction of area of material as
                                                                    pad must be adequate to prevent leak-                     follows:
                                                                    age.                                                        (1) The test is required on 2 speci-
                                                                      (i) Hydrostatic test. Cylinders must                    mens cut from 1 cylinder, or part
                                                                    withstand a hydrostatic test as follows:                  thereof heat-treated as required, taken
                                                                      (1) The test must be by water-jacket,                   at random out of each lot of 200 or less.
                                                                    or other suitable method, operated so                     For lots of 30 or less, physical tests are
                                                                    as to obtain accurate data. The pres-                     authorized to be made on a ring at
                                                                    sure gauge must permit reading to an                      least 8 inches long cut from each cyl-
                                                                    accuracy of 1 percent. The expansion                      inder and subjected to same heat treat-
                                                                    gauge must permit reading of total ex-                    ment as the finished cylinder.
                                                                    pansion to an accuracy either of 1 per-                     (2) Specimens must conform to the
                                                                    cent or 0.1 cubic centimeter.                             following:
                                                                      (2) Pressure must be maintained for                       (i) A gauge length of 8 inches with a
                                                                    at least 30 seconds and sufficiently                      width of not over 11⁄2 inches, a gauge
                                                                    longer to ensure complete expansion.                      length of 2 inches with a width of not
                                                                    Any internal pressure applied after                       over 11⁄2 inches, or a gauge length at
                                                                    heat-treatment and previous to the of-                    least 24 times the thickness with a
                                                                    ficial test may not exceed 90 percent of                  width not over 6 times the thickness is
                                                                    the test pressure. If, due to failure of                  authorized when a cylinder wall is not
                                                                    the test apparatus, the test pressure                     over 3⁄16 inch thick.
                                                                    cannot be maintained, the test may be                       (ii) The specimen, exclusive of grip
                                                                    repeated at a pressure increased by 10                    ends, may not be flattened. Grip ends
                                                                    percent or 100 psig, whichever is the                     may be flattened to within one inch of
                                                                    lower.                                                    each end of the reduced section.
                                                                      (3) Permanent volumetric expansion                        (iii) When size of cylinder does not
                                                                    may not exceed 10 percent of total vol-                   permit securing straight specimens,
                                                                    umetric expansion at test pressure.                       the specimens may be taken in any lo-
                                                                      (4) Cylinders must be tested as fol-                    cation or direction and may be
                                                                    lows:                                                     straightened or flattened cold, by pres-
                                                                      (i) At least one cylinder selected at                   sure only, not by blows. When speci-
                                                                    random out of each lot of 200 or less                     mens are so taken and prepared, the in-
                                                                    must be tested as outlined in para-                       spector’s report must show in connec-
                                                                    graphs (i)(1), (i)(2), and (i)(3) of this sec-            tion with record of physical tests de-
                                                                    tion to at least two times service pres-                  tailed information in regard to such
                                                                    sure.                                                     specimens.
                                                                      (ii) All cylinders not tested as out-                     (iv) Heating of a specimen for any
                                                                    lined in paragraph (i)(4)(i) of this sec-                 purpose is not authorized.
                                                                    tion must be examined under pressure                        (3) The yield strength in tension
                                                                    of at least two times service pressure                    must be the stress corresponding to a
                                                                    and show no defect.                                       permanent strain of 0.2 percent of the
                                                                      (j) Flattening test. After the hydro-                   gauge length. The following conditions
                                                                    static test, a flattening test must be                    apply:
                                                                    performed on one cylinder taken at                          (i) The yield strength must be deter-
                                                                    random out or each lot of 200 or less, by                 mined by either the ‘‘offset’’ method or
                                                                    placing the cylinder between wedge                        the ‘‘extension under load’’ method as
                                                                    shaped knife edges having a 60° in-                       prescribed in ASTM E 8 (IBR, see § 171.7
                                                                    cluded angle, rounded to 1⁄2-inch radius.                 of this subchapter).
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                                                                    The longitudinal axis of the cylinder                       (ii) In using the ‘‘extension under
                                                                    must be at a 90-degree angle to knife                     load’’ method, the total strain (or ‘‘ex-
                                                                    edges during the test. For lots of 30 or                  tension under load’’) corresponding to

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.51

                                                                    the stress at which the 0.2 percent per-                  cessed bottom of the cylinder, consti-
                                                                    manent strain occurs may be deter-                        tuting an integral and non-pressure
                                                                    mined with sufficient accuracy by cal-                    part of the cylinder.
                                                                    culating the elastic extension of the                       (4) On a metal plate attached to the
                                                                    gauge length under appropriate load                       top of the cylinder or permanent part
                                                                    and adding thereto 0.2 percent of the                     thereof; sufficient space must be left on
                                                                    gauge length. Elastic extension cal-                      the plate to provide for stamping at
                                                                    culations must be based on an elastic                     least six retest dates; the plate must be
                                                                    modulus of 30,000,000. In the event of                    at least 1⁄16-inch thick and must be at-
                                                                    controversy, the entire stress-strain                     tached by welding, or by brazing. The
                                                                    diagram must be plotted and the yield                     brazing rod must melt at a tempera-
                                                                    strength determined from the 0.2 per-                     ture of 1100 °F. Welding or brazing
                                                                    cent offset.                                              must be along all the edges of the
                                                                      (iii) For the purpose of strain meas-                   plate.
                                                                    urement, the initial strain must be set                     (5) On the neck, neckring, valve boss,
                                                                    while the specimen is under a stress of                   valve protection sleeve, or similar part
                                                                    12,000 psi, and strain indicator reading                  permanently attached to the top of the
                                                                    must be set at the calculated cor-                        cylinder.
                                                                    responding strain.                                          (6) On the footring permanently at-
                                                                      (iv) Cross-head speed of the testing                    tached to the cylinder, provided the
                                                                    machine may not exceed 1⁄8 inch per                       water capacity of the cylinder does not
                                                                    minute during yield strength deter-                       exceed 25 pounds.
                                                                    mination.                                                 [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                      (l) Acceptable results for physical and                 amended at 62 FR 51561, Oct. 1, 1997; 66 FR
                                                                    flattening tests. Either of the following                 45385, 45388, Aug. 28, 2001; 67 FR 51653, Aug. 8,
                                                                    is an acceptable result:                                  2002; 68 FR 75748, Dec. 31, 2003]
                                                                      (1) An elongation of at least 40 per-
                                                                    cent for a 2-inch gauge length or at                      § 178.51 Specification 4BA welded or
                                                                    least 20 percent in other cases and                            brazed steel cylinders.
                                                                    yield strength not over 73 percent of                        (a) Type, size, and service pressure. A
                                                                    tensile strength. In this instance, a                     DOT 4BA cylinder is a cylinder, either
                                                                    flattening test is not required.                          spherical or cylindrical in shape, with
                                                                      (2) When cylinders are constructed of                   a water capacity of 1,000 pounds or less
                                                                    lap welded pipe, flattening test is re-                   and a service pressure of at least 225
                                                                    quired, without cracking, to 6 times                      and not over 500 psig. Closures made by
                                                                    the wall thickness. In such case, the                     the spinning process are not author-
                                                                    rings (crop ends) cut from each end of                    ized.
                                                                    pipe, must be tested with the weld 45°                       (1) Spherical type cylinders must be
                                                                    or less from the point of greatest                        made from two seamless hemispheres
                                                                    stress. If a ring fails, another from the                 joined by the welding of one circum-
                                                                    same end of pipe may be tested.                           ferential seam.
                                                                      (m) Rejected cylinders. Reheat treat-                      (2) Cylindrical type cylinders must be
                                                                    ment is authorized for rejected cyl-                      of circumferentially welded or brazed
                                                                    inder. Subsequent thereto, cylinders                      construction.
                                                                    must pass all prescribed tests to be ac-                     (b) Steel. The steel used in the con-
                                                                    ceptable. Repair of brazed seams by                       struction of the cylinder must be as
                                                                    brazing and welded seams by welding is                    specified in table 1 of appendix A to
                                                                    authorized.                                               this part.
                                                                      (n) Markings. Markings must be                             (c) Identification of material. Material
                                                                    stamped plainly and permanently in                        must be identified by any suitable
                                                                    any of the following locations on the                     method except that plates and billets
                                                                    cylinder:                                                 for hotdrawn cylinders must be marked
                                                                      (1) On shoulders and top heads when                     with the heat number.
                                                                    they are not less than 0.087-inch thick.                     (d) Manufacture. Cylinders must be
                                                                      (2) On side wall adjacent to top head                   manufactured using equipment and
                                                                    for side walls which are not less than                    processes adequate to ensure that each
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                                                                    0.090 inch thick.                                         cylinder produced conforms to the re-
                                                                      (3) On a cylindrical portion of the                     quirements of this subpart. No defect is
                                                                    shell which extends beyond the re-                        permitted that is likely to weaken the

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                                                                    § 178.51                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    finished cylinder appreciably. A rea-                     case of 4130× steel which may be used
                                                                    sonably smooth and uniform surface                        with proper welding procedure.
                                                                    finish is required. Exposed bottom                          (f) Wall thickness. The minimum wall
                                                                    welds on cylinders over 18 inches long                    thickness of the cylinder must meet
                                                                    must be protected by footrings.                           the following conditions:
                                                                      (1) Seams must be made as follows:                        (1) For any cylinder with an outside
                                                                      (i) Minimum thickness of heads and                      diameter of greater than 6 inches, the
                                                                    bottoms must be not less than 90 per-                     minimum wall thickness is 0.078 inch.
                                                                    cent of the required thickness of the                     In any case the minimum wall thick-
                                                                    side wall.                                                ness must be such that the calculated
                                                                      (ii) Circumferential seams must be                      wall stress at the minimum test pres-
                                                                    made by welding or by brazing. Heads                      sure may not exceed the lesser value of
                                                                    must be attached by brazing and must                      any of the following:
                                                                    have a driving fit with the shell, unless                   (i) The value shown in table 1 of ap-
                                                                    the shell is crimped, swedged or curled                   pendix A to this part, for the particular
                                                                    over the skirt or flange of the head and                  material under consideration;
                                                                    must be thoroughly brazed until com-                        (ii) One-half of the minimum tensile
                                                                    plete penetration by the brazing mate-                    strength of the material determined as
                                                                    rial of the brazed joint is secured.                      required in paragraph (j) of this sec-
                                                                    Depth of brazing from end of the shell                    tion;
                                                                    must be at least four times the thick-                      (iii) 35,000 psi; or
                                                                    ness of shell metal.                                        (iv) Further provided that wall stress
                                                                      (iii) Longitudinal seams in shells                      for cylinders having copper brazed lon-
                                                                    must be made by copper brazing, cop-                      gitudinal seams may not exceed 95 per-
                                                                    per alloy brazing, or by silver alloy                     cent of any of the above values. Meas-
                                                                    brazing. Copper alloy composition                         ured wall thickness may not include
                                                                    must be: Copper 95 percent minimum,                       galvanizing or other protective coat-
                                                                    Silicon 1.5 percent to 3.85 percent, Man-                 ing.
                                                                    ganese 0.25 percent to 1.10 percent. The                    (2) Cylinders that are cylindrical in
                                                                    melting point of the silver alloy braz-                   shape must have the wall stress cal-
                                                                    ing material must be in excess of 1,000                   culated by the formula:
                                                                    °F. The plate edge must be lapped at                      S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)
                                                                    least eight times the thickness of
                                                                    plate, laps being held in position, sub-                  Where:
                                                                    stantially metal to metal, by riveting                    S = wall stress in psi;
                                                                    or by electric spot-welding. Brazing                      P = minimum test pressure prescribed for
                                                                                                                                water jacket test;
                                                                    must be done by using a suitable flux
                                                                                                                              D = outside diameter in inches;
                                                                    and by placing brazing material on one                    d = inside diameter in inches.
                                                                    side of seam and applying heat until
                                                                    this material shows uniformly along                         (3) Cylinders that are spherical in
                                                                    the seam of the other side. Strength of                   shape must have the wall stress cal-
                                                                    longitudinal seam: Copper brazed lon-                     culated by the formula:
                                                                    gitudinal seam must have strength at                      S = PD / 4tE
                                                                    least 3⁄2 times the strength of the steel
                                                                    wall.                                                     Where:
                                                                      (2) Welding procedures and operators                    S = wall stress in psi;
                                                                    must be qualified in accordance with                      P = minimum test pressure prescribed for
                                                                                                                                water jacket test;
                                                                    CGA Pamphlet C–3 (IBR, see § 171.7 of                     D = outside diameter in inches;
                                                                    this subchapter).                                         t = minimum wall thickness in inches;
                                                                      (e) Welding and brazing. Only the                       E = 0.85 (provides 85 percent weld efficiency
                                                                    welding or brazing of neckrings,                            factor which must be applied in the girth
                                                                    footrings, handles, bosses, pads, and                       weld area and heat affected zones which
                                                                    valve protection rings to the tops and                      zone must extend a distance of 6 times wall
                                                                    bottoms of cylinders is authorized.                         thickness from center line of weld);
                                                                                                                              E = 1.0 (for all other areas).
                                                                    Provided that such attachments and
                                                                    the portion of the container to which                       (4) For a cylinder with a wall thick-
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                                                                    they are attached are made of weldable                    ness less than 0.100 inch, the ratio of
                                                                    steel, the carbon content of which may                    tangential length to outside diameter
                                                                    not exceed 0.25 percent except in the                     may not exceed 4.1.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.51

                                                                      (g) Heat treatment. Cylinders must be                   must permit reading of total expansion
                                                                    heat treated in accordance with the                       to an accuracy of either 1 percent or 0.1
                                                                    following requirements:                                   cubic centimeter.
                                                                      (1) Each cylinder must be uniformly                       (2) Pressure must be maintained for
                                                                    and properly heat treated prior to test                   at least 30 seconds and sufficiently
                                                                    by the applicable method shown in                         longer to ensure complete expansion.
                                                                    table 1 of appendix A to this part. Heat                  Any internal pressure applied after
                                                                    treatment must be accomplished after                      heat treatment and previous to the of-
                                                                    all forming and welding operations, ex-                   ficial test may not exceed 90 percent of
                                                                    cept that when brazed joints are used,                    the test pressure.
                                                                    heat treatment must follow any form-                        (3) Permanent volumetric expansion
                                                                    ing and welding operations, but may be                    may not exceed 10 percent of the total
                                                                    done before, during or after the brazing                  volumetric expansion at test pressure.
                                                                    operations.                                                 (4) Cylinders must be tested as fol-
                                                                      (2) Heat treatment is not required                      lows:
                                                                    after the welding or brazing of weldable
                                                                                                                                (i) At least one cylinder selected at
                                                                    low carbon parts to attachments of
                                                                                                                              random out of each lot of 200 or less
                                                                    similar material which have been pre-
                                                                                                                              must be tested as outlined in para-
                                                                    viously welded or brazed to the top or
                                                                                                                              graphs (i)(1), (i)(2), and (i)(3) of this sec-
                                                                    bottom of cylinders and properly heat
                                                                                                                              tion to at least two times service pres-
                                                                    treated, provided such subsequent
                                                                                                                              sure.
                                                                    welding or brazing does not produce a
                                                                                                                                (ii) All cylinders not tested as out-
                                                                    temperature in excess of 400 °F in any
                                                                                                                              lined in paragraph (i)(4)(i) of this sec-
                                                                    part of the top or bottom material.
                                                                                                                              tion must be examined under pressure
                                                                      (h) Openings in cylinders. Openings in
                                                                                                                              of at least two times service pressure
                                                                    cylinders must comply with the fol-
                                                                                                                              and show no defect.
                                                                    lowing requirements:
                                                                      (1) Any opening must be placed on                         (j) Physical test. A physical test must
                                                                    other than a cylindrical surface.                         be conducted to determine yield
                                                                      (2) Each opening in a spherical type                    strength, tensile strength, elongation,
                                                                    cylinder must be provided with a fit-                     and reduction of area of material, as
                                                                    ting, boss, or pad of weldable steel se-                  follows:
                                                                    curely attached to the container by fu-                     (1) The test is required on 2 speci-
                                                                    sion welding.                                             mens cut from one cylinder or part
                                                                      (3) Each opening in a cylindrical type                  thereof having passed the hydrostatic
                                                                    cylinder must be provided with a fit-                     test and heat-treated as required,
                                                                    ting, boss, or pad, securely attached to                  taken at random out of each lot of 200
                                                                    container by brazing or by welding.                       or less. Physical tests for spheres are
                                                                      (4) If threads are used, they must                      required on 2 specimens cut from flat
                                                                    comply with the following:                                representative sample plates of the
                                                                      (i) Threads must be clean-cut, even,                    same heat taken at random from the
                                                                    without checks and tapped to gauge.                       steel used to produce the spheres. This
                                                                      (ii) Taper threads must be of a length                  flat steel from which 2 specimens are
                                                                    not less than that specified for Amer-                    to be cut must receive the same heat
                                                                    ican Standard taper pipe threads.                         treatment as the spheres themselves.
                                                                      (iii) Straight threads, having at least                 Sample plates must be taken from each
                                                                    4 engaged threads, must have a tight                      lot of 200 or less spheres.
                                                                    fit and a calculated shear strength of                      (2) Specimens must conform to the
                                                                    at least 10 times the test pressure of                    following:
                                                                    the cylinder. Gaskets, adequate to pre-                     (i) A gauge length of 8 inches with a
                                                                    vent leakage, are required.                               width not over 11⁄2 inches, or a gauge
                                                                      (i) Hydrostatic test. Each cylinder                     length of 2 inches with a width not
                                                                    must successfully withstand a hydro-                      over 11⁄2 inches, or a gauge length at
                                                                    static test, as follows:                                  least 24 times the thickness with a
                                                                      (1) The test must be by water jacket,                   width not over 6 times the thickness is
                                                                    or other suitable method, operated so                     authorized when a cylinder wall is not
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                                                                    as to obtain accurate data. A pressure                    over 3⁄16 inch thick.
                                                                    gauge must permit reading to an accu-                       (ii) The specimen, exclusive of grip
                                                                    racy of 1 percent. An expansion gauge                     ends, may not be flattened. Grip ends

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                                                                    § 178.51                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    may be flattened to within one inch of                    strength above 50,000 psi to a maximum
                                                                    each end of the reduced section.                          of four such increments.
                                                                      (iii) When size of the cylinder does                      (l) Tests of welds. Except for brazed
                                                                    not permit securing straight speci-                       seams, welds must be tested as follows:
                                                                    mens, the specimens may be taken in                         (1) Tensile test. A specimen must be
                                                                    any location or direction and may be                      cut from one cylinder of each lot of 200
                                                                    straightened or flattened cold, by pres-                  or less, or welded test plate. The weld-
                                                                    sure only, not by blows. When speci-                      ed test plate must be of one of the
                                                                    mens are so taken and prepared, the in-                   heats in the lot of 200 or less which it
                                                                    spector’s report must show in connec-                     represents, in the same condition and
                                                                    tion with record of physical tests de-                    approximately the same thickness as
                                                                    tailed information in regard to such                      the cylinder wall except that in no case
                                                                    specimens.                                                must it be of a lesser thickness than
                                                                      (iv) Heating of a specimen for any                      that required for a quarter size Charpy
                                                                    purpose is not authorized.                                impact specimen. The weld must be
                                                                      (3) The yield strength in tension                       made by the same procedures and sub-
                                                                    must be the stress corresponding to a                     jected to the same heat treatment as
                                                                    permanent strain of 0.2 percent of the                    the major weld on the cylinder. The
                                                                    gauge length. The following conditions                    specimen must be taken from across
                                                                    apply:                                                    the major seam and must be prepared
                                                                      (i) The yield strength must be deter-                   and tested in accordance with and
                                                                    mined by either the ‘‘offset’’ method or                  must meet the requirements of CGA
                                                                    the ‘‘extension under load’’ method as                    Pamphlet C–3 (IBR, see § 171.7 of this
                                                                    prescribed in ASTM E 8 (IBR, see § 171.7                  subchapter). Should this specimen fail
                                                                    of this subchapter).                                      to meet the requirements, specimens
                                                                      (ii) In using the ‘‘extension under                     may be taken from two additional cyl-
                                                                    load’’ method, the total strain (or ‘‘ex-                 inders or welded test plates from the
                                                                    tension under load’’), corresponding to                   same lot and tested. If either of the lat-
                                                                    the stress at which the 0.2 percent per-                  ter specimens fail to meet the require-
                                                                    manent strain occurs may be deter-                        ments, the entire lot represented must
                                                                    mined with sufficient accuracy by cal-                    be rejected.
                                                                    culating the elastic extension of the                       (2) Guided bend test. A root bend test
                                                                    gauge length under appropriate load                       specimen must be cut from the cyl-
                                                                    and adding thereto 0.2 percent of the                     inder or welded test plate, used for the
                                                                    gauge length. Elastic extension cal-                      tensile test specified in paragraph (l)(1)
                                                                    culations must be based on an elastic                     of this section. Specimens must be
                                                                    modulus of 30,000,000. In the event of                    taken from across the major seam and
                                                                    controversy, the entire stress-strain                     must be prepared and tested in accord-
                                                                    diagram must be plotted and the yield                     ance with and must meet the require-
                                                                    strength determined from the 0.2 per-                     ments of CGA Pamphlet C–3.
                                                                    cent offset.                                                (3) Alternate guided-bend test. This
                                                                      (iii) For the purpose of strain meas-                   test may be used and must be as re-
                                                                    urement, the initial strain reference                     quired by CGA Pamphlet C–3. The spec-
                                                                    must be set while the specimen is                         imen must be bent until the elongation
                                                                    under a stress of 12,000 psi, and the                     at the outer surface, adjacent to the
                                                                    strain indicator reading must be set at                   root of the weld, between the lightly
                                                                    the calculated corresponding strain.                      scribed gage lines a to b, must be at
                                                                      (iv) Cross-head speed of the testing                    least 20 percent, except that this per-
                                                                    machine may not exceed 1⁄8 inch per                       centage may be reduced for steels hav-
                                                                    minute during yield strength deter-                       ing a tensile strength in excess of 50,000
                                                                    mination.                                                 psig, as provided in paragraph (k) of
                                                                      (k) Elongation. Physical test speci-                    this section.
                                                                    mens must show at least a 40 percent                        (m) Rejected cylinders. Reheat treat-
                                                                    elongation for a 2-inch gauge length or                   ment is authorized for rejected cyl-
                                                                    at least 20 percent in other cases. Ex-                   inders. Subsequent thereto, cylinders
                                                                    cept that these elongation percentages                    must pass all prescribed tests to be ac-
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                                                                    may be reduced numerically by 2 for 2-                    ceptable. Repair of brazed seams by
                                                                    inch specimens, and by 1 in other cases,                  brazing and welded seams by welding is
                                                                    for each 7,500 psi increment of tensile                   authorized.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                                                                                                § 178.53

                                                                      (n) Markings. Markings must be                                                                      sphere (two seamless hemispheres) or
                                                                    stamped plainly and permanently in                                                                    circumferentially welded cylinder (two
                                                                    one of the following locations on the                                                                 seamless drawn shells) with a water ca-
                                                                    cylinder:                                                                                             pacity not over 100 pounds and a serv-
                                                                      (1) On shoulders and top heads not                                                                  ice pressure of at least 300 but not over
                                                                    less than 0.087 inch thick.                                                                           500 psig. Cylinders closed in by spin-
                                                                      (2) On side wall adjacent to top head                                                               ning process are not authorized.
                                                                    for side walls not less than 0.090 inch
                                                                                                                                                                            (b) Steel. Open-hearth or electric steel
                                                                    thick.
                                                                                                                                                                          of uniform and weldable quality must
                                                                      (3) On a cylindrical portion of the
                                                                    shell which extends beyond the re-                                                                    be used. Content may not exceed the
                                                                    cessed bottom of the cylinder consti-                                                                 following: Carbon, 0.25; phosphorus,
                                                                    tuting an integral and non-pressure                                                                   0.045; sulphur, 0.050, except that the fol-
                                                                    part of the cylinder.                                                                                 lowing steels commercially known as
                                                                      (4) On a plate attached to the top of                                                               4130X and Type 304, 316, 321, and 347
                                                                    the cylinder or permanent part thereof;                                                               stainless steels may be used with prop-
                                                                    sufficient space must be left on the                                                                  er welding procedure. A heat of steel
                                                                    plate to provide for stamping at least                                                                made under table 1 in this paragraph
                                                                    six retest dates; the plate must be at                                                                (b), check chemical analysis of which is
                                                                    least 1⁄16 inch thick and must be at-                                                                 slightly out of the specified range, is
                                                                    tached by welding, or by brazing at a                                                                 acceptable, if satisfactory in all other
                                                                    temperature of at least 1100 °F.,                                                                     respects, provided the tolerances shown
                                                                    throughout all edges of the plate.                                                                    in table 2 in this paragraph (b) are not
                                                                      (5) On the neck, neckring, valve boss,                                                              exceeded, except as approved by the As-
                                                                    valve protection sleeve, or similar part                                                              sociate Administrator. The following
                                                                    permanently attached to the top of the                                                                chemical analyses are authorized:
                                                                    cylinder.
                                                                      (6) On the footring permanently at-                                                                                         TABLE 1—4130X STEEL
                                                                    tached to the cylinder, provided the
                                                                    water capacity of the cylinder does not                                                                                             4130X                                            Percent
                                                                    exceed 25 pounds.
                                                                                                                                                                          Carbon ...........................................................        0.25/0.35.
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as                                                         Manganese ....................................................            0.40/0.60.
                                                                    amended at 66 FR 4535, Aug. 28, 2001; 67 FR                                                           Phosphorus ....................................................           0.04 max.
                                                                    16015, Sept. 27, 2002; 67 FR 51653, Aug. 8, 2002;                                                     Sulphur ..........................................................        0.05 max
                                                                    68 FR 75748, Dec. 31, 2003]                                                                           Silicon ............................................................      0.15/0.35.
                                                                                                                                                                          Chromium ......................................................           0.80/1.10.
                                                                    § 178.53 Specification 4D welded steel                                                                Molybdenum ..................................................             0.15/0.25.
                                                                         cylinders for aircraft use.                                                                      Zirconium .......................................................         None.
                                                                                                                                                                          Nickel .............................................................      None.
                                                                       (a) Type, size, and service pressure. A
                                                                    DOT 4D cylinder is a welded steel
                                                                                                                             TABLE 2—AUTHORIZED STAINLESS STEELS
                                                                                                                                                                                                          Stainless steels

                                                                                                                                                                         304                        316                        321                        347
                                                                                                                                                                       (percent)                  (percent)                  (percent)                  (percent)

                                                                    Carbon (max) ........................................................................                           0.08                       0.08                       0.08                       0.08
                                                                    Manganese (max) .................................................................                               2.00                       2.00                       2.00                       2.00
                                                                    Phosphorus (max) .................................................................                              .030                       .045                       .030                       .030
                                                                    Sulphur (max) ........................................................................                          .030                       .030                       .030                       .030
                                                                    Silicon (max) .........................................................................                           .75                      1.00                         .75                        .75
                                                                    Nickel .....................................................................................              8.0/11.0                 10.0/14.0                    9.0/13.0                   9.0/13.0
                                                                    Chromium ..............................................................................                 18.0/20.0                  16.0/18.0                  17.0/20.0                  17.0/20.0
                                                                    Molybdenum ..........................................................................          ........................                2.0/3.0       ........................   ........................
                                                                    Titanium .................................................................................     ........................   ........................                       (1)    ........................
                                                                    Columbium ............................................................................         ........................   ........................   ........................                       (2)
                                                                       1 Titanium      may not be less than 5C and not more than 0.60%.
                                                                       2 Columbium       may not be less than 10C and not more than 1.0%.
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                                                                    § 178.53                                                                                                                 49 CFR Ch. I (10–1–09 Edition)

                                                                                                                             TABLE 3—CHECK ANALYSIS TOLERANCES
                                                                                                                                                                                                                            Tolerance (percent) over
                                                                                                                                                                                                                             the maximum limit or
                                                                                                                                                          Limit or maximum specified                                        under the minimum limit
                                                                                            Element                                                                 (percent)
                                                                                                                                                                                                                           Under min-             Over max-
                                                                                                                                                                                                                           imum limit             imum limit

                                                                    Carbon .....................................................     To 0.15 incl ......................................................................                0.01            0.01
                                                                                                                                     Over 0.15 to 0.40 incl ......................................................                        .03            .04
                                                                    Manganese ..............................................         To 0.60 incl ......................................................................                  .03            .03
                                                                                                                                     Over 1.15 to 2.50 incl ......................................................                        .05            .05
                                                                    Phosphorus 1 ...........................................         All ranges ........................................................................   ....................          .01
                                                                    Sulphur ....................................................     All ranges ........................................................................   ....................          .01
                                                                    Silicon ......................................................   To 0.30 incl ......................................................................                  .02            .03
                                                                                                                                     Over 0.30 to 1.00 incl ......................................................                        .05            .05
                                                                    Nickel .......................................................   Over 5.30 to 10.00 incl ....................................................                         .10            .10
                                                                                                                                     Over 10.00 to 14.00 incl ..................................................                          .15            .15
                                                                    Chromium ................................................        To 0.90 incl ......................................................................                  .03            .03
                                                                                                                                     Over 0.90 to 2.10 incl ......................................................                        .05            .05
                                                                                                                                     Over 15.00 to 20.00 incl ..................................................                          .20            .20
                                                                    Molybdenum ............................................          To 0.20 incl ......................................................................                  .01            .01
                                                                                                                                     Over 0.20 to 0.40 incl ......................................................                        .02            .02
                                                                                                                                     Over 1.75 to 3.0 incl ........................................................                       .10            .10
                                                                    Titanium ...................................................     All ranges ........................................................................                  .05            .05
                                                                    Columbium ..............................................         All ranges ........................................................................                  .05            .05
                                                                       1 Rephosphorized           steels not subject to check analysis for phosphorus.



                                                                      (c) Identification of material. Material                                                         Where:
                                                                    must be identified by any suitable                                                                 S = wall stress in psi;
                                                                    method except that plates and billets                                                              P = test pressure prescribed for water jacket
                                                                    for hotdrawn cylinders must be marked                                                                test, i.e., at least two times service pres-
                                                                    with the heat number.                                                                                sure, in psig;
                                                                      (d) Manufacture. Cylinders must be                                                               D = outside diameter in inches;
                                                                                                                                                                       t = minimum wall thickness in inches;
                                                                    manufactured using equipment and
                                                                                                                                                                       E = 0.85 (provides 85 percent weld efficiency
                                                                    processes adequate to ensure that each                                                               factor which must be applied in the girth
                                                                    cylinder produced conforms to the re-                                                                weld area and heat affected zones which
                                                                    quirements of this subpart. No defect is                                                             zone must extend a distance of 6 times wall
                                                                    permitted that is likely to weaken the                                                               thickness from center line of weld);
                                                                    finished container appreciably. A rea-                                                             E = 1.0 (for all other areas).
                                                                    sonably smooth and uniform surface
                                                                                                                                                                        (2) Calculation for a cylinder must be
                                                                    finish is required. Welding procedures
                                                                                                                                                                       made by the formula:
                                                                    and operators must be qualified in ac-
                                                                    cordance with CGA Pamphlet C–3 (IBR,                                                               S = [P(1.3D2 + 0.4d2)] / (D2 ¥ dT12)
                                                                    see § 171.7 of this subchapter).
                                                                                                                                                                       Where:
                                                                      (e) Wall thickness. The wall stress at
                                                                    the minimum test pressure may not ex-                                                              S = wall stress in psi;
                                                                                                                                                                       P = test pressure prescribed for water jacket
                                                                    ceed 24,000 psi, except where steels
                                                                                                                                                                         test, i.e., at least two times service pres-
                                                                    commercially known as 4130X, types                                                                   sure, in psig;
                                                                    304, 316, 321, and 347 stainless steels are                                                        D = outside diameter in inches;
                                                                    used, stress at the test pressures may                                                             d = inside diameter in inches.
                                                                    not exceed 37,000 psi. The minimum
                                                                                                                                                                         (f) Heat treatment. The completed cyl-
                                                                    wall thickness for any container hav-
                                                                                                                                                                       inders must be uniformly and properly
                                                                    ing a capacity of 1,100 cubic inches or
                                                                                                                                                                       heat-treated prior to tests.
                                                                    less is 0.04 inch. The minimum wall
                                                                    thickness for any container having a                                                                 (g) Openings in container. Openings in
                                                                    capacity in excess of 1,100 cubic inches                                                           cylinders must comply with the fol-
                                                                    is 0.095 inch. Calculations must be done                                                           lowing:
                                                                    by the following:                                                                                    (1) Each opening in the container, ex-
                                                                                                                                                                       cept those for safety devices, must be
                                                                      (1) Calculation for a ‘‘sphere’’ must
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                                                                                                                                                                       provided with a fitting, boss, or pad, se-
                                                                    be made by the formula:
                                                                                                                                                                       curely attached to the container by
                                                                    S = PD / 4tE                                                                                       brazing or by welding or by threads. If

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.53

                                                                    threads are used, they must comply                          (ii) The test must be between parallel
                                                                    with the following:                                       steel plates on a press with a welded
                                                                      (i) Threads must be clean cut, even,                    seam at right angles to the plates. Any
                                                                    without checks, and tapped to gauge.                      projecting appurtenances may be cut
                                                                      (ii) Taper threads must be of a length                  off (by mechanical means only) prior to
                                                                    not less than that specified for Amer-                    crushing.
                                                                    ican Standard taper pipe threads.                           (2) One cylinder taken at random out
                                                                      (iii) Straight threads, having at least                 of each lot of 200 or less must be sub-
                                                                    4 engaged threads, must have a tight                      jected to a flattening test, as follows:
                                                                    fit and calculated shear strength of at                     (i) The test must be performed after
                                                                    least 10 times the test pressure of the                   the hydrostatic test.
                                                                    container. Gaskets, adequate to pre-                        (ii) The test must be between knife
                                                                    vent leakage, are required.                               edges, wedge shaped, 60° angle, rounded
                                                                      (2) Closure of a fitting, boss, or pad                  to 1⁄2 inch radius. For lots of 30 or less,
                                                                    must be adequate to prevent leakage.                      physical tests are authorized to be
                                                                      (h) Hydrostatic test. Each cylinder                     made on a ring at least 8 inches long
                                                                    must successfully withstand a hydro-                      cut from each cylinder and subjected to
                                                                    static test, as follows:                                  the same heat treatment as the fin-
                                                                      (1) The test must be by water-jacket,                   ished cylinder.
                                                                    or other suitable method, operated so                       (j) Physical test and specimens for
                                                                    as to obtain accurate data. A pressure                    spheres and cylinders. Spheres and cyl-
                                                                    gauge must permit a reading to an ac-                     inders must be subjected to a physical
                                                                    curacy of 1 percent. An expansion                         test as follows:
                                                                    gauge must permit reading of total ex-                      (1) Physical test for spheres are re-
                                                                    pansion to an accuracy of either 1 per-                   quired on 2 specimens cut from a flat
                                                                    cent or 0.1 cubic centimeter.                             representative sample plate of the
                                                                      (2) Pressure must be maintained for                     same heat taken at random from the
                                                                    at least 30 seconds and sufficiently                      steel used to produce the sphere. This
                                                                    longer to ensure complete expansion.                      flat steel from which the 2 specimens
                                                                    Any internal pressure applied after                       are to be cut must receive the same
                                                                    heat-treatment and previous to the of-                    heat-treatment as the spheres them-
                                                                    ficial test may not exceed 90 percent of                  selves. Sample plates must be taken for
                                                                    the test pressure. If, due to failure of                  each lot of 200 or less spheres.
                                                                    the test apparatus, the test pressure                       (2) Specimens for spheres must have
                                                                    cannot be maintained, the test may be                     a gauge length 2 inches with a width
                                                                    repeated at a pressure increased by 10                    not over 11⁄2 inches, or a gauge length
                                                                    percent or 100 psig, whichever is the                     at least 24 times the thickness with a
                                                                    lower.                                                    width not over 6 times the thickness is
                                                                      (3) Permanent volumetric expansion                      authorized when a wall is not over 3⁄16
                                                                    may not exceed 10 percent of the total                    inch thick.
                                                                    volumetric expansion at test pressure.                      (3) Physical test for cylinders is re-
                                                                      (4) Containers must be tested as fol-                   quired on 2 specimens cut from 1 cyl-
                                                                    lows:                                                     inder taken at random out of each lot
                                                                      (i) Each container to at least 2 times                  of 200 or less. For lots of 30 or less,
                                                                    service pressure; or                                      physical tests are authorized to be
                                                                      (ii) One container out of each lot of                   made on a ring at least 8 inches long
                                                                    200 or less to at least 3 times service                   cut from each cylinder and subjected to
                                                                    pressure. Others must be examined                         the same heat treatment as the fin-
                                                                    under pressure of 2 times service pres-                   ished cylinder.
                                                                    sure and show no defects.                                   (4) Specimens for cylinders must con-
                                                                      (i) Flattening test for spheres and cyl-                form to the following:
                                                                    inders. Spheres and cylinders must be                       (i) A gauge length of 8 inches with a
                                                                    subjected to a flattening test as fol-                    width not over 11⁄2 inches, or a gauge
                                                                    lows:                                                     length of 2 inches with a width not
                                                                      (1) One sphere taken at random out                      over 11⁄2 inches, or a gauge length at
                                                                    of each lot of 200 or less must be sub-                   least 24 times the thickness with a
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                                                                    jected to a flattening test as follows:                   width not over 6 times the thickness is
                                                                      (i) The test must be performed after                    authorized when a cylinder wall is not
                                                                    the hydrostatic test.                                     over 3⁄16 inch thick.

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                                                                    § 178.55                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                      (ii) The specimen, exclusive of grip                    must pass all prescribed tests to be ac-
                                                                    ends, may not be flattened. Grip ends                     ceptable. Repair of welded seams by
                                                                    may be flattened to within 1 inch of                      welding prior to reheat-treatment is
                                                                    each end of the reduced section. Heat-                    authorized.
                                                                    ing of the specimen for any purpose is                      (m) Marking. Marking on each con-
                                                                    not authorized.                                           tainer by stamping plainly and perma-
                                                                      (5) The yield strength in tension                       nently are only authorized where the
                                                                    must be the stress corresponding to a                     metal is at least 0.09 inch thick, or on
                                                                    permanent strain of 0.2 percent of the                    a metal nameplate permanently se-
                                                                    gauge length. The following conditions                    cured to the container by means other
                                                                    apply:                                                    than soft solder, or by means that
                                                                      (i) The yield strength must be deter-                   would not reduce the wall thickness.
                                                                    mined by either the ‘‘offset’’ method or                  [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    the ‘‘extension under load’’ method as                    amended at 66 FR 45386, 45388, Aug. 28, 2001;
                                                                    prescribed in ASTM E 8 (IBR, see § 171.7                  67 FR 51653, Aug. 8, 2002; 68 FR 75748, Dec. 31,
                                                                    of this subchapter).                                      2003]
                                                                      (ii) In using the ‘‘extension under
                                                                    load’’ method, the total strain (or ‘‘ex-                 § 178.55 Specification 4B240ET welded
                                                                    tension under load’’) corresponding to                         or brazed cylinders.
                                                                    the stress at which the 0.2 percent per-                     (a) Type, spinning process, size and
                                                                    manent strain occurs may be deter-                        service pressure. A DOT 4B240ET cyl-
                                                                    mined with sufficient accuracy by cal-                    inder is a brazed type cylinder made
                                                                    culating the elastic extension of the                     from electric resistance welded tubing.
                                                                    gauge length under appropriate load                       The maximum water capacity of this
                                                                    and adding thereto 0.2 percent of the                     cylinder is 12 pounds or 333 cubic
                                                                    gauge length. Elastic extension cal-                      inches and the service must be 240 psig.
                                                                    culations must be based on an elastic                     The maximum outside diameter of the
                                                                    modulus of 30,000,000. In the event of                    shell must be five inches and maximum
                                                                    controversy, the entire stress-strain                     length of the shell is 21 inches. Cyl-
                                                                    diagram must be plotted and the yield                     inders closed in by a spinning process
                                                                    strength determined from the 0.2 per-                     are authorized.
                                                                    cent offset.                                                 (b) Steel. Open-hearth, basic oxygen,
                                                                      (iii) For the purpose of strain meas-                   or electric steel of uniform quality
                                                                    urement, the initial strain must be set                   must be used. Plain carbon steel con-
                                                                    while the specimen is under a stress of                   tent may not exceed the following: Car-
                                                                    12,000 psi and the strain indicator read-                 bon, 0.25; phosphorus, 0.045; sulfur,
                                                                    ing being set at the calculated cor-                      0.050. The addition of other elements
                                                                    responding strain.                                        for alloying effect is prohibited.
                                                                      (iv) Cross-head speed of the testing                       (c) Identification of material. Material
                                                                    machine may not exceed 1⁄8 inch per                       must be identified by any suitable
                                                                    minute during yield strength deter-                       method.
                                                                    mination.                                                    (d) Manufacture. Cylinders must be
                                                                      (k) Acceptable results for physical and                 manufactured using equipment and
                                                                    flattening tests. Either of the following                 processes adequate to ensure that each
                                                                    is an acceptable result:                                  cylinder produced conforms to the re-
                                                                      (1) An elongation of at least 40 per-                   quirements of this subpart. No defect is
                                                                    cent for a 2 inch gauge length or at                      permitted that is likely to weaken the
                                                                    least 20 percent in other cases and                       finished cylinder appreciably. A rea-
                                                                    yield strength not over 73 percent of                     sonably smooth and uniform surface
                                                                    tensile strength. In this instance, the                   finish is required. Heads may be at-
                                                                    flattening test is not required.                          tached to shells by lap brazing or may
                                                                      (2) An elongation of at least 20 per-                   be formed integrally. The thickness of
                                                                    cent for a 2 inch gauge length or 10 per-                 the bottom of cylinders welded or
                                                                    cent in other cases. Flattening is re-                    formed by spinning is, under no condi-
                                                                    quired to 50 percent of the original out-                 tion, to be less than two times the min-
                                                                    side diameter without cracking.                           imum wall thickness of the cylindrical
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                                                                      (l) Rejected cylinders. Reheat-treat-                   shell. Such bottom thicknesses must be
                                                                    ment is authorized for rejected cyl-                      measured within an area bounded by a
                                                                    inders. Subsequent thereto, containers                    line representing the points of contact

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.55

                                                                    between the cylinder and the floor                          (h) Openings in cylinders. Openings in
                                                                    when the cylinder is in a vertical posi-                  cylinders must comply with the fol-
                                                                    tion. Seams must conform to the fol-                      lowing:
                                                                    lowing:                                                     (1) Each opening in cylinders, except
                                                                      (1) Circumferential seams must be by                    those for safety devices, must be pro-
                                                                    brazing only. Heads must be attached                      vided with a fitting, boss, or pad, se-
                                                                    to shells by the lap brazing method and                   curely attached to the cylinder by
                                                                    must overlap not less than four times                     brazing or by welding or by threads. A
                                                                    the wall thickness. Brazing material                      fitting, boss, or pad must be of steel
                                                                    must have a melting point of not less                     suitable for the method of attachment
                                                                    than 1000 °F. Heads must have a driving                   employed, and which need not be iden-
                                                                    fit with the shell unless the shell is                    tified or verified as to analysis, except
                                                                    crimped, swedged, or curled over the                      that if attachment is by welding, car-
                                                                    skirt or flange of the head and be thor-                  bon content may not exceed 0.25 per-
                                                                    oughly brazed until complete penetra-                     cent. If threads are used, they must
                                                                    tion of the joint by the brazing mate-                    comply with the following:
                                                                    rial is secured. Brazed joints may be re-                   (i) Threads must be clean cut, even
                                                                    paired by brazing.                                        without checks, and tapped to gauge.
                                                                      (2) Longitudinal seams in shell must                      (ii) Taper threads to be of length not
                                                                    be by electric resistance welded joints                   less than as specified for American
                                                                    only. No repairs to longitudinal joints                   Standard taper pipe threads.
                                                                    is permitted.                                               (iii) Straight threads, having at least
                                                                      (3) Welding procedures and operators                    4 engaged threads, to have tight fit and
                                                                    must be qualified in accordance with                      calculated shear strength at least 10
                                                                    CGA C–3 (IBR, see § 171.7 of this sub-                    times the test pressure of the cylinder;
                                                                    chapter).                                                 gaskets required, adequate to prevent
                                                                      (e) Welding or brazing. Only the at-                    leakage.
                                                                    tachment, by welding or brazing, to the                     (2) Closure of a fitting, boss, or pad
                                                                    tops and bottoms of cylinders of                          must be adequate to prevent leakage.
                                                                    neckrings, footrings, handles, bosses,                      (i) Hydrostatic test. Each cylinder
                                                                    pads, and valve protection rings is au-                   must successfully withstand a hydro-
                                                                    thorized. Provided that such attach-                      static test as follows:
                                                                    ments and the portion of the container                      (1) The test must be by water-jacket,
                                                                    to which they are attached are made of                    or other suitable method, operated so
                                                                    weldable steel, the carbon content of                     as to obtain accurate data. The pres-
                                                                    which may not exceed 0.25 percent.                        sure gauge must permit reading to an
                                                                      (f) Wall thickness. The wall stress                     accuracy of 1 percent. The expansion
                                                                    must be at least two times the service                    gauge must permit reading of total ex-
                                                                    pressure and may not exceed 18,000 psi.                   pansion to an accuracy of either 1 per-
                                                                    The minimum wall thickness is 0.044                       cent or 0.1 cubic centimeter.
                                                                    inch. Calculation must be made by the                       (2) Pressure must be maintained for
                                                                    following formula:                                        at least 30 seconds and sufficiently
                                                                                                                              longer to ensure complete expansion.
                                                                    S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)
                                                                                                                              Any internal pressure applied after
                                                                    Where:                                                    heat-treatment and previous to the of-
                                                                    S = wall stress in psig;                                  ficial test may not exceed 90 percent of
                                                                    P = 2 times service pressure;                             the test pressure. If, due to failure of
                                                                    D = outside diameter in inches;                           the test apparatus, the test pressure
                                                                    d = inside diameter in inches.                            cannot be maintained, the test may be
                                                                      (g) Heat treatment. Heads formed by                     repeated at a pressure increased by 10
                                                                    drawing or pressing must be uniformly                     percent or 100 psig, whichever is the
                                                                    and properly heat treated prior to                        lower.
                                                                    tests. Cylinders with integral formed                       (3) Permanent volumetric expansion
                                                                    heads or bases must be subjected to a                     may not exceed 10 percent of total vol-
                                                                    normalizing operation. Normalizing                        umetric expansion at test pressure.
                                                                    and brazing operations may be com-                          (4) Cylinders must be tested as fol-
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                                                                    bined, provided the operation is carried                  lows:
                                                                    out at a temperature in excess of the                       (i) At least one cylinder selected at
                                                                    upper critical temperature of the steel.                  random out of each lot of 200 or less

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                                                                    § 178.55                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    must be tested as outlined in para-                         (iii) When size of cylinder does not
                                                                    graphs (i)(1), (i)(2), and (i)(3) of this sec-            permit securing straight specimens,
                                                                    tion to at least two times service pres-                  the specimens may be taken in any lo-
                                                                    sure.                                                     cation or direction and may be
                                                                      (ii) All cylinders not tested as out-                   straightened or flattened cold by pres-
                                                                    lined in paragraph (i)(4)(i) of this sec-                 sure only, not by blows. When speci-
                                                                    tion must be examined under pressure                      mens are so taken and prepared, the in-
                                                                    of at least two times service pressure                    spector’s report must show in connec-
                                                                    and show no defect.                                       tion with record of physical tests de-
                                                                      (5) Each 1000 cylinders or less succes-                 tailed information in regard to such
                                                                    sively produced each day must con-                        specimens.
                                                                    stitute a lot. One cylinder must be se-                     (iv) Heating of a specimen for any
                                                                    lected      from       each       lot     and             purpose is not authorized.
                                                                    hydrostatically tested to destruction.                      (3) The yield strength in tension
                                                                    If this cylinder bursts below five times                  must be the stress corresponding to a
                                                                    the service pressure, then two addi-                      permanent strain of 0.2 percent of the
                                                                    tional cylinders must be selected and                     gauge length. The following conditions
                                                                    subjected to this test. If either of these                apply:
                                                                    cylinders fails by bursting below five                      (i) The yield strength must be deter-
                                                                    times the service pressure then the en-                   mined by either the ‘‘offset’’ method or
                                                                    tire lot must be rejected. All cylinders                  the ‘‘extension under load’’ method as
                                                                    constituting a lot must be of identical                   prescribed in ASTM E 8 (IBR, see § 171.7
                                                                    size, construction heat-treatment, fin-                   of this subchapter).
                                                                    ish, and quality.                                           (ii) In using the ‘‘extension under
                                                                      (j) Flattening test. Following the hy-                  load’’ method, the total strain (or ‘‘ex-
                                                                    drostatic test, one cylinder taken at                     tension under load’’) corresponding to
                                                                    random out of each lot of 200 or less,                    the stress at which the 0.2 percent per-
                                                                    must be subjected to a flattening test                    manent strain occurs may be deter-
                                                                    that is between knife edges, wedge                        mined with sufficient accuracy by cal-
                                                                    shaped, 60° angle, rounded to 1⁄2 inch ra-                culating the elastic extension of the
                                                                    dius.                                                     gauge length under appropriate load
                                                                      (k) Physical test. A physical test must                 and adding thereto 0.2 percent of the
                                                                    be conducted to determine yield                           gauge length. Elastic extension cal-
                                                                    strength, tensile strength, elongation,                   culations must be based on an elastic
                                                                    and reduction of area of material, as                     modulus of 30,000,000. In the event of
                                                                    follows:                                                  controversy, the entire stress-strain
                                                                      (1) The test is required on 2 speci-                    diagram must be plotted and the yield
                                                                    mens cut from 1 cylinder, or part                         strength determined from the 0.2 per-
                                                                    thereof heat-treated as required, taken                   cent offset.
                                                                    at random out of each lot of 200 or less                    (iii) For the purpose of strain meas-
                                                                    in the case of cylinders of capacity                      urement, the initial strain must be set
                                                                    greater than 86 cubic inches and out of                   while the specimen is under a stress of
                                                                    each lot of 500 or less for cylinders hav-                12,000 psi and the strain indicator read-
                                                                    ing a capacity of 86 cubic inches or                      ing being set at the calculated cor-
                                                                    less.                                                     responding strain.
                                                                      (2) Specimens must conform to the                         (iv) Cross-head speed of the testing
                                                                    following:                                                machine may not exceed 1⁄8 inch per
                                                                      (i) A gauge length of 8 inches with a                   minute during yield strength deter-
                                                                    width not over 11⁄2 inches, a gauge                       mination.
                                                                    length of 2 inches with a width not                         (l) Acceptable results for physical and
                                                                    over 11⁄2 inches, or a gauge length at                    flattening tests. Acceptable results for
                                                                    least 24 times the thickness with a                       the physical and flattening tests are an
                                                                    width not over 6 times the thickness is                   elongation of at least 40 percent for a 2
                                                                    authorized when a cylinder wall is not                    inch gauge length or at least 20 percent
                                                                    over 3⁄16 inch thick.                                     in other cases and a yield strength not
                                                                      (ii) The specimen, exclusive of grip                    over 73 percent of tensile strength. In
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                                                                    ends, may not be flattened. Grip ends                     this instance the flattening test is re-
                                                                    may be flattened to within one inch of                    quired, without cracking, to six times
                                                                    each end of the reduced section.                          the wall thickness with a weld 90° from

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.56

                                                                    the direction of the applied load. Two                      (o) Marking. Markings on each cyl-
                                                                    rings cut from the ends of length of                      inder must be by stamping plainly and
                                                                    pipe used in production of a lot may be                   permanently on shoulder, top head,
                                                                    used for the flattening test provided                     neck or valve protection collar which
                                                                    the rings accompany the lot which                         is permanently attached to the cyl-
                                                                    they represent in all thermal proc-                       inders and forming an integral part
                                                                    essing operations. At least one of the                    thereof, provided that cylinders not
                                                                    rings must pass the flattening test.                      less than 0.090 inch thick may be
                                                                       (m) Leakage test. All spun cylinders                   stamped on the side wall adjacent to
                                                                    and plugged cylinders must be tested                      top head.
                                                                    for leakage by gas or air pressure after                  [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    the bottom has been cleaned and is free                   amended at 66 FR 45386, Aug. 28, 2001; 67 FR
                                                                    from all moisture, subject to the fol-                    51653, Aug. 8, 2002; 68 FR 75748, 75749, Dec. 31,
                                                                    lowing conditions:                                        2003]
                                                                       (1) Pressure, approximately the same
                                                                                                                              § 178.56 Specification 4AA480 welded
                                                                    as but no less than service pressure,                          steel cylinders.
                                                                    must be applied to one side of the fin-
                                                                    ished bottom over an area of at least                        (a) Type, size, and service pressure. A
                                                                    1⁄16 of the total area of the bottom but                  DOT 4AA480 cylinder is a welded steel
                                                                    not less than 3⁄4 inch in diameter, in-                   cylinder having a water capacity
                                                                    cluding the closure, for at least 1                       (nominal) not over 1,000 pounds water
                                                                    minute, during which time the other                       capacity and a service pressure of 480
                                                                    side of the bottom exposed to pressure                    psig. Closures welded by spinning proc-
                                                                    must be covered with water and closely                    ess not permitted.
                                                                    examined for indications of leakage.                         (b) Steel. The limiting chemical com-
                                                                    Except as provided in paragraph (n) of                    position of steel authorized by this
                                                                    this section, cylinders which are leak-                   specification must be as shown in table
                                                                    ing must be rejected.                                     I of appendix A to this part.
                                                                       (2) A spun cylinder is one in which an                    (c) Identification of material. Material
                                                                    end closure in the finished cylinder has                  must be identified by any suitable
                                                                    been welded by the spinning process.                      method except that plates and billets
                                                                                                                              for hotdrawn cylinders must be marked
                                                                       (3) A plugged cylinder is one in which
                                                                                                                              with the heat number.
                                                                    a permanent closure in the bottom of a
                                                                                                                                 (d) Manufacture. Cylinders must be
                                                                    finished cylinder has been effected by a
                                                                                                                              manufactured using equipment and
                                                                    plug.
                                                                                                                              processes adequate to ensure that each
                                                                       (4) As a safety precaution, if the                     cylinder produced conforms to the re-
                                                                    manufacturer elects to make this test                     quirements of this subpart. No defect is
                                                                    before the hydrostatic test, he should                    permitted that is likely to weaken the
                                                                    design his apparatus so that the pres-                    finished cylinder appreciably. A rea-
                                                                    sure is applied to the smallest area                      sonably smooth and uniform surface
                                                                    practicable, around the point of clo-                     finish is required. Exposed bottom
                                                                    sure, and so as to use the smallest pos-                  welds on cylinders over 18 inches long
                                                                    sible volume of air or gas.                               must be protected by footrings. Min-
                                                                       (n) Rejected cylinders. Repairs of re-                 imum thickness of heads and bottoms
                                                                    jected cylinders is authorized. Cyl-                      may not be less than 90 percent of the
                                                                    inders that are leaking must be re-                       required thickness of the side wall.
                                                                    jected, except that:                                      Seams must be made as follows:
                                                                       (1) Spun cylinders rejected under the                     (1) Circumferential seams must be
                                                                    provisions of paragraph (m) of this sec-                  welded. Brazing is not authorized.
                                                                    tion may be removed from the spun                            (2) Longitudinal seams are not per-
                                                                    cylinder category by drilling to remove                   mitted.
                                                                    defective material, tapping, and plug-                       (3) Welding procedures and operators
                                                                    ging.                                                     must be qualified in accordance with
                                                                       (2) Brazed joints may be rebrazed.                     CGA C–3 (IBR, see § 171.7 of this sub-
                                                                       (3) Subsequent to the operations                       chapter).
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                                                                    noted in paragraphs (n)(1) and (n)(2) of                     (e) Welding. Only the welding of
                                                                    this section, acceptable cylinders must                   neckrings, footrings, bosses, pads, and
                                                                    pass all prescribed tests.                                valve protection rings to the tops and

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                                                                    § 178.56                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    bottoms of cylinders is authorized.                         (2) Each opening in the cylinder, ex-
                                                                    Provided that such attachments are                        cept those for safety devices, must be
                                                                    made of weldable steel, the carbon con-                   provided with a fitting boss, or pad, se-
                                                                    tent of which does not exceed 0.25 per-                   curely attached to the cylinder by
                                                                    cent.                                                     welding or by threads. If threads are
                                                                      (f) Wall thickness. The wall thickness                  used they must comply with the fol-
                                                                    of the cylinder must conform to the                       lowing:
                                                                    following:                                                  (i) Threads must be clean-cut, even
                                                                      (1) For cylinders with an outside di-                   without checks and cut to gauge.
                                                                    ameter over 5 inches, the minimum                           (ii) Taper threads to be of length not
                                                                    wall thickness is 0.078 inch. In any                      less than as specified for American
                                                                    case, the minimum wall thickness                          Standard taper pipe threads.
                                                                    must be such that the calculated wall                       (iii) Straight threads having at least
                                                                    stress at the minimum test pressure (in                   6 engaged threads, must have a tight
                                                                    paragraph (i) of this section) may not                    fit and a calculated shear strength at
                                                                    exceed the lesser value of either of the                  least 10 times the test pressure of the
                                                                    following:                                                cylinder. Gaskets, adequate to prevent
                                                                      (i) One-half of the minimum tensile                     leakage, are required.
                                                                    strength of the material determined as                      (3) Closure of a fitting, boss or pad
                                                                    required in paragraph (j) of this sec-                    must be adequate to prevent leakage.
                                                                    tion; or                                                    (i) Hydrostatic test. Each cylinder
                                                                      (ii) 35,000 psi.                                        must successfully withstand a hydro-
                                                                      (2) Calculation must be made by the                     static test as follows:
                                                                    formula:                                                    (1) The test must be by water jacket,
                                                                                                                              or other suitable method, operated so
                                                                    S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)                        as to obtain accurate data. The pres-
                                                                    Where:                                                    sure gauge must permit reading to an
                                                                                                                              accuracy of 1 percent. The expansion
                                                                    S = wall stress in psi;
                                                                                                                              gauge must permit reading of total ex-
                                                                    P = minimum test pressure prescribed for
                                                                      water jacket test;                                      pansion to an accuracy of either 1 per-
                                                                    D = outside diameter in inches;                           cent or 0.1 cubic centimeter.
                                                                    d = inside diameter in inches.                              (2) Pressure must be maintained for
                                                                                                                              at least 30 seconds or sufficiently
                                                                      (3) The ratio of tangential length to                   longer to assure complete expansion.
                                                                    outside diameter may not exceed 4.0 for                   Any internal pressure applied after
                                                                    cylinders with a wall thickness less                      heat-treatment and before the official
                                                                    than 0.100 inch.                                          test may not exceed 90 percent of the
                                                                      (g) Heat treatment. Each cylinder                       test pressure. If, due to failure of test
                                                                    must be uniformly and properly heat                       apparatus, the test pressure cannot be
                                                                    treated prior to tests. Any suitable                      maintained, the test may be repeated
                                                                    heat treatment in excess of 1100 °F is                    at a pressure increased by 10 percent or
                                                                    authorized except that liquid quench-                     100 psig, whichever is lower.
                                                                    ing is not permitted. Heat treatment                        (3) Permanent volumetric expansion
                                                                    must be accomplished after all forming                    may not exceed 10 percent of the total
                                                                    and welding operations. Heat treat-                       volumetric expansion at test pressure.
                                                                    ment is not required after welding                          (4) Cylinders must be tested as fol-
                                                                    weldable low carbon parts to attach-                      lows:
                                                                    ments of similar material which have                        (i) At least one cylinder selected at
                                                                    been previously welded to the top or                      random out of each lot of 200 or less
                                                                    bottom of cylinders and properly heat                     must be tested as described in para-
                                                                    treated, provided such subsequent                         graphs (i)(1), (i)(2), and (i)(3) of this sec-
                                                                    welding does not produce a tempera-                       tion, to at least two times service pres-
                                                                    ture in excess of 400 °F., in any part of                 sure. If a selected cylinder fails, then
                                                                    the top or bottom material.                               two additional specimens must be se-
                                                                      (h) Openings in cylinders. Openings in                  lected at random from the same lot and
                                                                    cylinders must conform to the fol-                        subjected to the prescribed test. If ei-
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                                                                    lowing:                                                   ther of these fails the test, then each
                                                                      (1) All openings must be in the heads                   cylinder in that lot must be so tested;
                                                                    or bases.                                                 and

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.56

                                                                      (ii) Each cylinder not tested as pre-                   manent strain occurs may be deter-
                                                                    scribed in paragraph (i)(4)(i) of this sec-               mined with sufficient accuracy by cal-
                                                                    tion must be examined under pressure                      culating the elastic extension of the
                                                                    of at least two times service pressure                    gauge length under appropriate load
                                                                    and must show no defect. A cylinder                       and adding thereto 0.2 percent of the
                                                                    showing a defect must be rejected un-                     gauge length. Elastic extension cal-
                                                                    less it may be requalified under para-                    culations must be based on an elastic
                                                                    graph (m) of this section.                                modulus of 30,000,000. In the event of
                                                                      (j) Physical test. A physical test must                 controversy, the entire stress-strain
                                                                    be conducted to determine yield                           diagram must be plotted and the yield
                                                                    strength, tensile strength, elongation,                   strength determined from the 0.2 per-
                                                                    and reduction of area of material, as                     cent offset.
                                                                    follows:                                                    (iii) For the purpose of strain meas-
                                                                      (1) The test is required on 2 speci-                    urement, the initial strain reference
                                                                    mens cut from one cylinder having                         must be set while the specimen is
                                                                    passed the hydrostatic test, or part                      under a stress of 12,000 psi and the
                                                                    thereof heat-treated as required, taken                   strain indicator reading being set at
                                                                    at random out of each lot of 200 or less.                 the calculated corresponding strain.
                                                                      (2) Specimens must conform to the                         (iv) Cross-head speed of the testing
                                                                    following:                                                machine may not exceed 1⁄8 inch per
                                                                      (i) A gauge length of 8 inches with a                   minute during yield strength deter-
                                                                    width not over 11⁄2 inches, a gauge                       mination.
                                                                    length of 2 inches with a width not
                                                                                                                                (k) Elongation. Physical test speci-
                                                                    over 11⁄2 inches, or a gauge length at
                                                                                                                              mens must show at least a 40 percent
                                                                    least 24 times the thickness with a
                                                                                                                              elongation for 2-inch gauge lengths or
                                                                    width not over 6 times thickness is au-
                                                                                                                              at least a 20 percent elongation in
                                                                    thorized when the cylinder wall is not
                                                                                                                              other cases. Except that these elon-
                                                                    over 3⁄16 inch thick.
                                                                                                                              gation percentages may be reduced nu-
                                                                      (ii) The specimen, exclusive of grip
                                                                                                                              merically by 2 for 2-inch specimens and
                                                                    ends, may not be flattened. Grip ends
                                                                                                                              by 1 in other cases for each 7,500 psi in-
                                                                    may be flattened to within one inch of
                                                                    each end of the reduced section.                          crement of tensile strength above 50,000
                                                                      (iii) When size of cylinder does not                    psi to a maximum of four such incre-
                                                                    permit securing straight specimens,                       ments.
                                                                    the specimens may be taken in any lo-                       (l) Tests of welds. Welds must be test-
                                                                    cation or direction and may be                            ed as follows:
                                                                    straightened or flattened cold, by pres-                    (1) Tensile test. A specimen must be
                                                                    sure only, not by blows. When speci-                      cut from one cylinder of each lot of 200
                                                                    mens are so taken and prepared, the in-                   or less, or a welded test plate. The
                                                                    spector’s report must show in connec-                     welded test plate must be of one of the
                                                                    tion with record of physical tests de-                    heats in the lot of 200 or less which it
                                                                    tailed information in regard to such                      represents, in the same condition and
                                                                    specimens.                                                approximately the same thickness as
                                                                      (iv) Heating of a specimen for any                      the cylinder wall except that it may
                                                                    purpose is not authorized.                                not be of a lesser thickness than that
                                                                      (3) The yield strength in tension                       required for a quarter size Charpy im-
                                                                    must be the stress corresponding to a                     pact specimen. The weld must be made
                                                                    permanent strain of 0.2 percent of the                    by the same procedures and subjected
                                                                    gauge length. The following conditions                    to the same heat treatment as the
                                                                    apply:                                                    major weld on the cylinder. The speci-
                                                                      (i) The yield strength must be deter-                   mens must be taken across the major
                                                                    mined by either the ‘‘offset’’ method or                  seam and must be prepared and tested
                                                                    the ‘‘extension under load’’ method as                    in accordance with and must meet the
                                                                    prescribed in ASTM E 8 (IBR, see § 171.7                  requirements of CGA Pamphlet C–3.
                                                                    of this subchapter).                                      Should this specimen fail to meet the
                                                                      (ii) In using the ‘‘extension under                     requirements, specimens may be taken
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                                                                    load’’ method, the total strain (or ‘‘ex-                 from two additional cylinders or weld-
                                                                    tension under load’’), corresponding to                   ed test plates from the same lot and
                                                                    the stress at which the 0.2 percent per-                  tested. If either of the latter specimens

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                                                                    § 178.57                                                                     49 CFR Ch. I (10–1–09 Edition)

                                                                    fail to meet the requirements, the en-                    inder is a fusion welded insulated cyl-
                                                                    tire lot represented must be rejected.                    inder with a water capacity (nominal)
                                                                       (2) Guided bend test. A root bend test                 not over 1,000 pounds water capacity
                                                                    specimen must be cut from the cyl-                        and a service pressure of at least 40 but
                                                                    inder or a welded test plate, used for                    not greater than 500 psig conforming to
                                                                    the tensile test specified in paragraph                   the following requirements:
                                                                    (l)(1) of this section. Specimens must                      (1) For liquefied hydrogen service,
                                                                    be taken from across the major seam                       the cylinders must be designed to stand
                                                                    and must be prepared and tested in ac-                    on end, with the axis of the cylindrical
                                                                    cordance with and must meet the re-                       portion vertical.
                                                                    quirements of CGA Pamphlet C–3.                             (2) The design service temperature is
                                                                       (3) Alternate guided-bend test. This                   the coldest temperature for which a
                                                                    test may be used and must be as re-                       cylinder is suitable. The required de-
                                                                    quired by CGA Pamphlet C–3. The spec-                     sign service temperatures for each
                                                                    imen must be bent until the elongation                    cryogenic liquid is as follows:
                                                                    at the outer surface, adjacent to the
                                                                    root of the weld, between the lightly                       Cryogenic liquid                     Design service temperature
                                                                    scribed gage lines-a to b, is at least 20                 Argon ......................   Minus   320 °F or colder.
                                                                    percent, except that this percentage                      Helium ....................    Minus   452 °F or colder.
                                                                    may be reduced for steels having a ten-                   Hydrogen ................      Minus   42 3 °F or colder.
                                                                    sile strength in excess of 50,000 psi, as                 Neon .......................   Minus   411 °F or colder.
                                                                    provided in paragraph (k) of this sec-                    Nitrogen ..................    Minus   320 °F or colder.
                                                                                                                              Oxygen ...................     Minus   320 °F or colder.
                                                                    tion.
                                                                       (m) Rejected cylinders. Reheat treat-
                                                                    ment of rejected cylinders is author-                       (b) Material. Material use in the con-
                                                                    ized. Subsequent thereto, cylinders                       struction of this specification must
                                                                    must pass all prescribed tests to be ac-                  conform to the following:
                                                                    ceptable. Repair of welded seams by                         (1) Inner containment vessel (cylinder).
                                                                    welding is authorized.                                    Designations and limiting chemical
                                                                       (n) Markings. Markings must be                         compositions of steel authorized by
                                                                    stamped plainly and permanently in                        this specification must be as shown in
                                                                    one of the following locations on the                     table 1 in paragraph (o) of this section.
                                                                    cylinder:                                                   (2) Outer jacket. Steel or aluminum
                                                                       (1) On shoulders and top heads not                     may be used subject to the require-
                                                                    less than 0.087 inch thick.                               ments of paragraph (o)(2) of this sec-
                                                                       (2) On neck, valve boss, valve protec-                 tion.
                                                                    tion sleeve, or similar part perma-                         (c) Identification of material. Material
                                                                    nently attached to top end of cylinder.                   must be identified by any suitable
                                                                       (3) On a plate attached to the top of                  method.
                                                                    the cylinder or permanent part thereof:                     (d) Manufacture. Cylinders must be
                                                                    sufficient space must be left on the                      manufactured using equipment and
                                                                    plate to provide for stamping at least                    processes adequate to ensure that each
                                                                    six retest dates: the plate must be at                    cylinder produced conforms to the re-
                                                                    least 1⁄16 inch thick and must be at-                     quirements of this subpart and to the
                                                                    tached by welding or by brazing at a                      following requirements:
                                                                    temperature of at least 1100 °F,                            (1) No defect is permitted that is
                                                                    throughout all edges of the plate.                        likely to weaken the finished cylinder
                                                                       (4) Variations in location of mark-                    appreciably. A reasonably smooth and
                                                                    ings authorized only when necessitated                    uniform surface finish is required. The
                                                                    by lack of space.                                         shell portion must be a reasonably true
                                                                                                                              cylinder.
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    amended at 66 FR 45386, Aug. 28, 2001; 67 FR                (2) The heads must be seamless, con-
                                                                    51653, Aug. 8, 2002; 68 FR 75748, 75749, Dec. 31,         cave side to the pressure, hemi-
                                                                    2003]                                                     spherical or ellipsoidal in shape with
                                                                                                                              the major diameter not more than
                                                                    § 178.57 Specification 4L welded insu-                    twice the minor diameter. Minimum
                                                                         lated cylinders.
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                                                                                                                              thickness of heads may not be less
                                                                       (a) Type, size, service pressure, and de-              than 90 percent of the required thick-
                                                                    sign service temperature. A DOT 4L cyl-                   ness of the sidewall. The heads must be

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.57

                                                                    reasonably true to shape, have no ab-                       (3) For welding the cylinder, each
                                                                    rupt shape changes, and the skirts                        procedure and operator must be quali-
                                                                    must be reasonably true to round.                         fied in accordance with the sections of
                                                                       (3) The surface of the cylinder must                   CGA Pamphlet C–3 that apply. In addi-
                                                                    be insulated. The insulating material                     tion, impact tests of the weld must be
                                                                    must be fire resistant. The insulation                    performed in accordance with para-
                                                                    on non-evacuated jackets must be cov-                     graph (l) of this section as part of the
                                                                    ered with a steel jacket not less than                    qualification of each welding procedure
                                                                    0.060-inch thick or an aluminum jacket                    and operator.
                                                                    not less than 0.070 inch thick, so con-                     (4) Brazing, soldering and threading
                                                                    structed that moisture cannot come in                     are permitted only for joints not made
                                                                    contact with the insulating material. If                  directly to the cylinder body. Threads
                                                                    a vacuum is maintained in the insula-                     must comply with the requirements of
                                                                    tion space, the evacuated jacket must                     paragraph (h) of this section.
                                                                    be designed for a minimum collapsing                        (f) Wall thickness. The minimum wall
                                                                    pressure of 30 psig differential whether                  thickness of the cylinder must be such
                                                                    made of steel or aluminum. The con-                       that the calculated wall stress at the
                                                                    struction must be such that the total                     minimum required test pressure may
                                                                    heat transfer, from the atmosphere at                     not exceed the least value of the fol-
                                                                    ambient temperature to the contents                       lowing:
                                                                    of the cylinder, will not exceed 0.0005                     (1) 45,000 psi.
                                                                    Btu per hour, per Fahrenheit degree                         (2) One-half of the minimum tensile
                                                                    differential in temperature, per pound                    strength across the welded seam deter-
                                                                    of water capacity of the cylinder. For                    mined in paragraph (l) of this section.
                                                                    hydrogen, cryogenic liquid service, the                     (3) One-half of the minimum tensile
                                                                    total heat transfer, with a temperature                   strength of the base metal determined
                                                                    differential of 520 Fahrenheit degrees,                   as required in paragraph (j) of this sec-
                                                                    may not exceed that required to vent                      tion.
                                                                    30 SCF of hydrogen gas per hour.                            (4) The yield strength of the base
                                                                       (4) For a cylinder having a design                     metal determined as required in para-
                                                                    service temperature colder than minus                     graph (l) of this section.
                                                                    320 °F, a calculation of the maximum                        (5) Further provided that wall stress
                                                                    weight of contents must be made and                       for    cylinders    having  longitudinal
                                                                    that weight must be marked on the                         seams may not exceed 85 percent of the
                                                                                                                              above value, whichever applies.
                                                                    cylinder as prescribed in § 178.35.
                                                                                                                                (6) Calculation must be made by the
                                                                       (5) Welding procedures and oper-
                                                                                                                              following formula:
                                                                    ations must be qualified in accordance
                                                                    with CGA Pamphlet C–3 (IBR, see                           S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)
                                                                    § 171.7 of this subchapter). In addition,                 where:
                                                                    an impact test of the weld must be per-                   S = wall stress in pounds psi;
                                                                    formed in accordance with paragraph                       P = minimum test pressure prescribed for
                                                                    (l) of this section as part of the quali-                   pressure test in psig;
                                                                    fication of each welding procedure and                    D = outside diameter in inches;
                                                                    operator.                                                 d = inside diameter in inches.
                                                                       (e) Welding. Welding of the cylinder                     (g) Heat treatment. Heat treatment is
                                                                    must be as follows:                                       not permitted.
                                                                       (1) All seams of the cylinder must be                    (h) Openings in cylinder. Openings in
                                                                    fusion welded. A means must be pro-                       cylinders must conform to the fol-
                                                                    vided for accomplishing complete pene-                    lowing:
                                                                    tration of the joint. Only butt or joggle                   (1) Openings are permitted in heads
                                                                    butt joints for the cylinder seams are                    only. They must be circular and may
                                                                    authorized. All joints in the cylinder                    not exceed 3 inches in diameter or one
                                                                    must have reasonably true alignment.                      third of the cylinder diameter, which-
                                                                       (2) All attachments to the sidewalls                   ever is less. Each opening in the cyl-
                                                                    and heads of the cylinder must be by                      inder must be provided with a fitting,
                                                                    fusion welding and must be of a                           boss or pad, either integral with, or se-
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                                                                    weldable material complying with the                      curely attached to, the cylinder body
                                                                    impact requirements of paragraph (l) of                   by fusion welding. Attachments to a
                                                                    this section.                                             fitting, boss or pad may be made by

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                                                                    § 178.57                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    welding, brazing, mechanical attach-                      permanent strain of 0.2 percent of the
                                                                    ment, or threading.                                       gauge length. The following conditions
                                                                       (2) Threads must comply with the fol-                  apply:
                                                                    lowing:                                                     (i) The yield strength must be deter-
                                                                       (i) Threads must be clean-cut, even,                   mined by either the ‘‘offset’’ method or
                                                                    without checks and cut to gauge.                          the ‘‘extension under load’’ method as
                                                                       (ii) Taper threads to be of a length                   prescribed in ASTM E 8 (IBR, see § 171.7
                                                                    not less than that specified for NPT.                     of this subchapter).
                                                                       (iii) Straight threads must have at                      (ii) In using the ‘‘extension under
                                                                    least 4 engaged threads, tight fit and                    load’’ method, the total strain (or ‘‘ex-
                                                                    calculated shear strength at least 10                     tension under load’’), corresponding to
                                                                    times the test pressure of the cylinder.                  the stress at which the 0.2 percent per-
                                                                    Gaskets, which prevent leakage and                        manent strain occurs may be deter-
                                                                    are inert to the hazardous material,                      mined with sufficient accuracy by cal-
                                                                    are required.                                             culating the elastic expansion of the
                                                                       (i) Pressure test. Each cylinder, before               gauge length under appropriate load
                                                                    insulating and jacketing, must be ex-                     and adding thereto 0.2 percent of the
                                                                    amined under a pressure of at least 2                     gauge length. Elastic extension cal-
                                                                    times the service pressure maintained                     culations must be based on the elastic
                                                                    for at least 30 seconds without evidence                  modulus of the material used. In the
                                                                    of leakage, visible distortion or other                   event of controversy, the entire stress-
                                                                    defect. The pressure gauge must permit                    strain diagram must be plotted and the
                                                                    reading to an accuracy of 1 percent.                      yield strength determined from the 0.2
                                                                       (j) Physical test. A physical test must                percent offset.
                                                                    be conducted to determine yield                             (iii) For the purpose of strain meas-
                                                                    strength, tensile strength, and elon-                     urement, the initial strain reference
                                                                    gation as follows:                                        must be set while the specimen is
                                                                       (1) The test is required on 2 speci-                   under a stress of 12,000 psi and the
                                                                    mens selected from material of each                       strain indicator reading being set at
                                                                    heat and in the same condition as that                    the calculated corresponding strain.
                                                                    in the completed cylinder.                                  (iv) Cross-head speed of the testing
                                                                       (2) Specimens must conform to the                      machine may not exceed 1⁄8 inch per
                                                                    following:                                                minute during yield strength deter-
                                                                       (i) A gauge length of 8 inches with a                  mination.
                                                                    width not over 11⁄2 inches, a gauge                         (k) Acceptable results for physical tests.
                                                                    length of 2 inches with width not over                    Physical properties must meet the lim-
                                                                    11⁄2 inches, or a gauge length at least 24                its specified in paragraph (o)(1), table 1,
                                                                    times thickness with a width not over                     of this section, for the particular steel
                                                                    6 times thickness (authorized when cyl-                   in the annealed condition. The speci-
                                                                    inder wall is not over 1⁄16 inch thick).                  mens must show at least a 20 percent
                                                                       (ii) The specimen, exclusive of grip                   elongation for a 2-inch gage length. Ex-
                                                                    ends, may not be flattened. Grip ends                     cept that the percentage may be re-
                                                                    may be flattened to within one inch of                    duced numerically by 2 for each 7,500
                                                                    each end of the reduced section.                          psi increment of tensile strength above
                                                                       (iii) When size of the cylinder does                   100,000 psi to a maximum of 5 such in-
                                                                    not permit securing straight speci-                       crements. Yield strength and tensile
                                                                    mens, the specimens may be taken in                       strength must meet the requirements
                                                                    any location or direction and may be                      of paragraph (o)(1), table 1, of this sec-
                                                                    straightened or flattened cold by pres-                   tion.
                                                                    sure only, not by blows. When speci-                        (l) Tests of welds. Welds must be test-
                                                                    mens are so taken and prepared, the in-                   ed as follows:
                                                                    spector’s report must show in connec-                       (1) Tensile test. A specimen must be
                                                                    tion with record of physical tests de-                    cut from one cylinder of each lot of 200
                                                                    tailed information in regard to such                      or less, or welded test plate. The weld-
                                                                    specimens.                                                ed test plate must be of one of the
                                                                       (iv) Heating of a specimen for any                     heats in the lot of 200 or less which it
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                                                                    purpose is not authorized.                                represents, in the same condition and
                                                                       (3) The yield strength in tension                      approximately the same thickness as
                                                                    must be the stress corresponding to a                     the cylinder wall except that it may

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                               § 178.57

                                                                    not be of a lesser thickness than that                    spects to ASTM E 23 (IBR, see § 171.7 of
                                                                    required for a quarter size Charpy im-                    this subchapter). Each set of impact
                                                                    pact specimen. The weld must be made                      specimens must be taken across the
                                                                    by the same procedures and subjected                      weld and have the notch located in the
                                                                    to the same heat treatment as the                         weld metal. When the cylinder mate-
                                                                    major weld on the cylinder. The speci-                    rial thickness is 2.5 mm or thicker, im-
                                                                    men must be taken across the major                        pact specimens must be cut from a cyl-
                                                                    seam and must be prepared in accord-                      inder or welded test plate used for the
                                                                    ance with and must meet the require-                      tensile or bend test specimens. The di-
                                                                    ments of CGA Pamphlet C–3. Should                         mension along the axis of the notch
                                                                    this specimen fail to meet the require-                   must be reduced to the largest possible
                                                                    ments, specimens may be taken from                        of 10 mm, 7.5 mm, 5 mm or 2.5 mm, de-
                                                                    two additional cylinders or welded test                   pending upon cylinder thickness. When
                                                                    plates from the same lot and tested. If                   the material in the cylinder or welded
                                                                    either of the latter specimens fails to                   test plate is not of sufficient thickness
                                                                    meet the requirements, the entire lot                     to prepare 2.5 mm impact test speci-
                                                                    represented must be rejected.                             mens, 2.5 mm specimens must be pre-
                                                                       (2) Guided bend test. A ‘‘root’’ bend                  pared from a welded test plate made
                                                                    test specimen must be cut from the                        from 1⁄8 inch thick material meeting
                                                                    cylinder or welded test plate, used for                   the requirements specified in para-
                                                                    the tensile test specified in paragraph                   graph (o)(1), table 1, of this section and
                                                                    (l)(1) of this section and from any other                 having a carbon analysis of .05 min-
                                                                    seam or equivalent welded test plate if                   imum, but not necessarily from one of
                                                                    the seam is welded by a procedure dif-                    the heats used in the lot of cylinders.
                                                                    ferent from that used for the major                       The test piece must be welded by the
                                                                    seam. Specimens must be taken across                      same welding procedure as used on the
                                                                    the particular seam being tested and                      particular cylinder seam being quali-
                                                                    must be prepared and tested in accord-                    fied and must be subjected to the same
                                                                    ance with and must meet the require-                      heat treatment.
                                                                    ments of CGA Pamphlet C–3.                                  (vi) Impact test specimens must be
                                                                       (3) Alternate guided-bend test. This                   cooled to the design service tempera-
                                                                    test may be used and must be as speci-                    ture. The apparatus for testing the
                                                                    fied in CGA Pamphlet C–3. The speci-                      specimens must conform to require-
                                                                    men must be bent until the elongation                     ments of ASTM Standard E 23. The test
                                                                    at the outer surface, adjacent to the                     piece, as well as the handling tongs,
                                                                    root of the weld, between the lightly                     must be cooled for a length of time suf-
                                                                    scribed gage lines a to b, is at least 20                 ficient to reach the service tempera-
                                                                    percent, except that this percentage                      ture. The temperature of the cooling
                                                                    may be reduced for steels having a ten-                   device must be maintained within a
                                                                    sile strength in excess of 100,000 psig, as               range of plus or minus 3 °F. The speci-
                                                                    provided in paragraph (c) of this sec-                    men must be quickly transferred from
                                                                    tion.                                                     the cooling device to the anvil of the
                                                                       (4) Impact tests. One set of three im-                 testing machine and broken within a
                                                                    pact test specimens (for each test)                       time lapse of not more than six sec-
                                                                    must be prepared and tested for deter-                    onds.
                                                                    mining the impact properties of the de-                     (vii) The impact properties of each
                                                                    posited weld metal—                                       set of impact specimens may not be
                                                                       (i) As part of the qualification of the                less than the values in the following
                                                                    welding procedure.                                        table:
                                                                       (ii) As part of the qualification of the
                                                                                                                                                                         Minimum
                                                                    operators.                                                                                        impact value      Minimum
                                                                                                                                                                                      impact value
                                                                       (iii) For each ‘‘heat’’ of welding rodor                                                        required for   permitted on
                                                                                                                                      Size of specimen                avg. of each
                                                                    wire used.                                                                                         set of three   one only of a
                                                                                                                                                                                       set of three
                                                                       (iv) For each 1,000 feet of weld made                                                            specimens        (ft.-lb.)
                                                                                                                                                                          (ft.-lb.)
                                                                    with the same heat of welding rod or
                                                                    wire.                                                     10   mm×10 mm ......................             15              10
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                                                                       (v) All impact test specimens must be                  10   mm×7.5 mm .....................             12.5             8.5
                                                                    of the charpy type, keyhole or milled                     10   mm×5 mm ........................            10               7.0
                                                                                                                              10   mm×2.5 mm .....................              5               3.5
                                                                    U-notch, and must conform in all re-

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                                                                    § 178.57                                                                       49 CFR Ch. I (10–1–09 Edition)

                                                                      (viii) When the average value of the                    ceeded. The following chemical anal-
                                                                    three specimens equals or exceeds the                     yses and physical properties are au-
                                                                    minimum value permitted for a single                      thorized:
                                                                    specimen and the value for more than
                                                                    one specimen is below the required av-                                 TABLE 1—AUTHORIZED MATERIALS
                                                                    erage value, or when the value for one                                                                                Chemical analysis,
                                                                                                                                                 Designation
                                                                    specimen is below the minimum value                                                                                    limits in percent
                                                                    permitted for a single specimen, a                        Carbon 1 .............................................     0.08 max.
                                                                    retest of three additional specimens                      Manganese ........................................         2.00 max.
                                                                    must be made. The value of each of                        Phosphorus ........................................        0.045 max.
                                                                    these retest specimens must equal or                      Sulphur ..............................................     0.030 max.
                                                                                                                              Silicon ................................................   1.00 max.
                                                                    exceed the required average value.                        Nickel .................................................   8.00–10.50.
                                                                    When an erratic result is caused by a                     Chromium ..........................................        18.00–20.00.
                                                                    defective specimen, or there is uncer-                    Molybdenum ......................................          None.
                                                                                                                              Titanium .............................................     None.
                                                                    tainty in test procedure, a retest is au-                 Columbium .........................................        None.
                                                                    thorized.                                                   1 The carbon analysis must be reported to the nearest hun-
                                                                      (m) Radiographic examination. Cyl-                      dredth of one percent.
                                                                    inders must be subject to a radio-
                                                                    graphic examination as follows:                                         TABLE 2—PHYSICAL PROPERTIES
                                                                      (1) The techniques and acceptability
                                                                                                                                                                                                     Physical
                                                                    of radiographic inspection must con-                                                                                            properties
                                                                    form to the standards set forth in CGA                                                                                          (annealed)
                                                                    Pamphlet C–3.                                             Tensile strength, p.s.i. (minimum) .......................                75,000
                                                                      (2) One finished longitudinal seam                      Yield strength, p.s.i. (minimum) ...........................              30,000
                                                                    must be selected at random from each                      Elongation in 2 inches (minimum) percent ..........                           30.0
                                                                                                                              Elongation other permissible gauge lengths
                                                                    lot of 100 or less successively produced                    (minimum) percent ...........................................               15.0
                                                                    and be radiographed throughout its en-
                                                                    tire length. Should the radiographic
                                                                    examination fail to meet the require-                            TABLE 3—CHECK ANALYSIS TOLERANCES
                                                                    ments of paragraph (m)(1) of this sec-                                                                                          Tolerance
                                                                    tion, two additional seams of the same                                                                                           over the
                                                                                                                                                             Limit or specified range               maximum
                                                                    lot must be examined, and if either of                          Elements                         (percent)                    limit or under
                                                                    these fail to meet the requirements of                                                                                        the minimum
                                                                                                                                                                                                        limit
                                                                    (m)(1) of this section, only those pass-
                                                                    ing are acceptable.                                       Carbon ...............       To 0.030, incl ...................             0.005
                                                                      (n) Rejected cylinders. Reheat treat-                                                Over 0.30 to 0.20, incl .....                  0.01
                                                                                                                              Manganese ........           To 1.00 incl ......................             .03
                                                                    ment of rejected cylinders is author-                                                  Over 1.00 to 3.00, incl .....                  0.04
                                                                    ized. Subsequent thereto, cylinders                       Phosphorus 1 .....           To 0.040, incl ...................             0.005
                                                                    must pass all prescribed tests to be ac-                                               Over 0.040 to 0.020 incl ..                    0.010
                                                                                                                              Sulphur ..............       To .40 incl ........................           0.005
                                                                    ceptable. Welds may be repaired by                        Silicon ................     To 1.00, incl .....................            0.05
                                                                    suitable methods of fusion welding.                       Nickel .................     Over 5.00 to 10.00, incl ...                   0.10
                                                                      (o) Authorized materials of construc-                                                Over 10.00 to 20.00, incl                      0.15
                                                                                                                              Chromium ..........          Over 15.00 to 20.00, incl                      0.20
                                                                    tion. Authorized materials of construc-
                                                                                                                                1 Rephosphorized steels not subject to check analysis for
                                                                    tion are as follows:
                                                                                                                              phosphorus.
                                                                      (1) Inner containment vessel (cylinder).
                                                                    Electric furnace steel of uniform qual-                     (2) Outer jacket. (i) Nonflammable
                                                                    ity must be used. Chemical analysis                       cryogenic liquids. Cylinders intended
                                                                    must conform to ASTM A 240/A 240M                         for use in the transportation of non-
                                                                    (IBR, see § 171.7 of this subchapter),                    flammable cryogenic liquid must have
                                                                    Type 304 stainless steel. Chemical anal-                  an outer jacket made of steel or alu-
                                                                    ysis must conform to ASTM A240, Type                      minum.
                                                                    304 Stainless Steel. A heat of steel                        (ii) Flammable cryogenic liquids.
                                                                    made under table 1 and table 2 in this                    Cylinders intended for use in the trans-
                                                                    paragraph (o)(1) is acceptable, even                      portation of flammable cryogenic liq-
                                                                    though its check chemical analysis is                     uid must have an outer jacket made of
                                                                    slightly out of the specified range, if it                steel.
                                                                                                                                (p) Markings. (1) Markings must be
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                                                                    is satisfactory in all other respects,
                                                                    provided the tolerances shown in table                    stamped plainly and permanently on
                                                                    3 in this paragraph (o)(1) are not ex-                    shoulder or top head of jacket or on a

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                                                    § 178.58

                                                                    permanently attached plate or head                        paragraph (b), check chemical analysis
                                                                    protective ring.                                          of which is slightly out of the specified
                                                                       (2) The letters ‘‘ST’’, followed by the                range, is acceptable, if satisfactory in
                                                                    design service temperature (for exam-                     all other respects, provided the toler-
                                                                    ple, ST–423F), must be marked on cyl-                     ances shown in table 2 in this para-
                                                                    inders having a design service tempera-                   graph (b) are not exceeded except as ap-
                                                                    ture of colder than minus 320 °F only.                    proved by the Associate Administrator.
                                                                    Location to be just below the DOT                         The following chemical analyses are
                                                                    mark.                                                     authorized:
                                                                       (3) The maximum weight of contents,
                                                                    in pounds (for example, ‘‘Max. Content                                 TABLE 1—AUTHORIZED MATERIALS
                                                                    51 #’’), must be marked on cylinders                                                  4130                                              Percent
                                                                    having a design service temperature
                                                                    colder than minus 320 °F only. Loca-                      Carbon ........................................................       0.28/0.33.
                                                                                                                              Manganese .................................................           0.40/0.60.
                                                                    tion to be near symbol.                                   Phosphorus ................................................           0.040 max.
                                                                       (4) Special orientation instructions                   Sulfur ..........................................................     0.040 max.
                                                                    must be marked on the cylinder (for                       Silicon .........................................................     0.15/0.35.
                                                                    example, THIS END UP), if the cyl-                        Chromium ...................................................          0.80/1.10.
                                                                                                                              Molybdenum ...............................................            0.15/0.25.
                                                                    inder is used in an orientation other
                                                                    than vertical with openings at the top
                                                                    of the cylinder.                                                 TABLE 2—CHECK ANALYSIS TOLERANCES
                                                                       (5) If the jacket of the cylinder is                                                                                       Tolerance (per-
                                                                    constructed of aluminum, the letters                                                                                           cent) over the
                                                                                                                                                                                                  maximum limit or
                                                                    ‘‘AL’’ must be marked after the service                                                                                        under the min-
                                                                    pressure marking. Example: DOT-4L150                           Element                  Limit or maximum                         imum limit
                                                                                                                                                            specified (percent)
                                                                    AL.                                                                                                                             Under            Over
                                                                       (6) Except for serial number and jack-                                                                                        min-            max-
                                                                                                                                                                                                    imum            imum
                                                                    et material designation, each marking                                                                                            limit           limit
                                                                    prescribed in this paragraph (p) must
                                                                    be duplicated on each cylinder by any                     Carbon ............        Over 0.15 to 0.40 incl                   .03 .......      .04
                                                                                                                              Manganese .....            To 0.60 incl .................           .03 .......      .03
                                                                    suitable means.                                           Phosphorus1 ...            All ranges ....................          ..............   .01
                                                                       (q) Inspector’s report. In addition to                 Sulphur ...........        All ranges ....................          ..............   .01
                                                                    the information required by § 178.35, the                 Silicon .............      To 0.30 incl .................           .02 .......      .03
                                                                                                                                                         Over 0.30 to 1.00 incl                   .05 .......      .05
                                                                    inspector’s reports must contain infor-                   Chromium .......           To 0.90 incl .................           .03 .......      .03
                                                                    mation on:                                                                           Over 0.90 to 2.10 incl                   .05 .......      .05
                                                                       (1) The jacket material and insula-                    Molybdenum ...             To 0.20 incl .................           .01 .......      .01
                                                                    tion type;                                                                           Over 0.20 to 0.40, incl                  .02 .......      .02
                                                                       (2) The design service temperature                       1 Rephosphorized steels not subject to check analysis for
                                                                                                                              phosphorus.
                                                                    ( °F); and
                                                                       (3) The impact test results, on a lot                     (c) Identification of material. Materials
                                                                    basis.                                                    must be identified by any suitable
                                                                                                                              method except that plates and billets
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    amended at 66 FR 45386–45388, Aug. 28, 2001; 67           for hot-drawn containers must be
                                                                    FR 51653, Aug. 8, 2002; 68 FR 75748, Dec. 31,             marked with the heat number.
                                                                    2003]                                                        (d) Manufacture. Cylinders must be
                                                                                                                              manufactured in accordance with the
                                                                    § 178.58 Specification 4DA welded steel                   following requirements:
                                                                         cylinders for aircraft use.                             (1) By best appliances and methods.
                                                                       (a) Type, size, and service pressure. A                No defect is acceptable that is likely to
                                                                    DOT 4DA is a welded steel sphere (two                     weaken the finished container appre-
                                                                    seamless hemispheres) or a circum-                        ciably. A reasonably smooth and uni-
                                                                    ferentially welded cylinder (two seam-                    form surface finish is required. No ab-
                                                                    less drawn shells) with a water capac-                    rupt change in wall thickness is per-
                                                                    ity not over 100 pounds and a service                     mitted. Welding procedures and opera-
                                                                    pressure of at least 500 but not over 900                 tors must be qualified in accordance
                                                                    psig.                                                     with CGA Pamphlet C–3 (IBR, see
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                                                                       (b) Steel. Open-hearth or electric steel               § 171.7 of this subchapter).
                                                                    of uniform quality must be used. A                           (2) All seams of the sphere or cyl-
                                                                    heat of steel made under table 1 in this                  inders must be fusion welded. Seams

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                                                                    § 178.58                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    must be of the butt or joggle butt type                     (2) The steel temperature on quench-
                                                                    and means must be provided for accom-                     ing must be that recommended for the
                                                                    plishing complete penetration of the                      steel analysis, but may not exceed 1,750
                                                                    joint.                                                    °F.
                                                                      (e) Welding. Attachments to the con-                      (3) The steel must be tempered at the
                                                                    tainer are authorized by fusion welding                   temperature most suitable for the
                                                                    provided that such attachments are                        analysis except that in no case shall
                                                                    made of weldable steel, the carbon con-                   the tempering temperature be less than
                                                                    tent of which may not exceed 0.25 per-                    1,000 °F.
                                                                    cent except in the case of 4130 steel.                      (4) The steel may be normalized at a
                                                                      (f) Wall thickness. The minimum wall                    temperature of 1,650 °F instead of being
                                                                    thickness must be such that the wall                      quenched, and containers so normal-
                                                                    stress at the minimum specified test                      ized need not be tempered.
                                                                    pressure may not exceed 67 percent of                       (5) All cylinders, if water quenched or
                                                                    the minimum tensile strength of the                       quenched with a liquid producing a
                                                                    steel as determined from the physical                     cooling rate in excess of 80 percent of
                                                                    and burst tests required and may not                      the cooling rate of water, must be in-
                                                                    be over 70,000 p.s.i. For any diameter                    spected by the magnetic particle or dye
                                                                    container, the minimum wall thickness                     penetrant method to detect the pres-
                                                                    is 0.040 inch. Calculations must be                       ence of quenching cracks. Any cylinder
                                                                    made by the formulas in (f)(1) or (f)(2)                  found to have a quench crack must be
                                                                    of this section:                                          rejected and may not be requalified.
                                                                      (1) Calculation for a sphere must be                      (h) Openings in container. Openings in
                                                                    made by the following formula:                            the container must comply with the
                                                                                                                              following requirements:
                                                                    S = PD / 4tE                                                (1) Each opening in the container
                                                                    Where:                                                    must be provided with a fitting, boss,
                                                                    S = wall stress in pounds psi;                            or pad of weldable steel securely at-
                                                                    P = test pressure prescribed for water jacket             tached to the container by fusion weld-
                                                                      test, i.e., at least 2 times service pressure,          ing.
                                                                      in psig;                                                  (2) Attachments to a fitting, boss, or
                                                                    D = outside diameter in inches;                           pad must be adequate to prevent leak-
                                                                    t = minimum wall thickness in inches;                     age. Threads must comply with the fol-
                                                                    E = 0.85 (provides 85 percent weld efficiency             lowing:
                                                                      factor which must be applied in the girth                 (i) Threads must be clean cut, even,
                                                                      weld area and heat affected zones which
                                                                                                                              without checks, and tapped to gauge.
                                                                      zone must extend a distance of 6 times wall
                                                                      thickness from center line of weld);                      (ii) Taper threads to be of length not
                                                                    E = 1.0 (for all other areas).                            less than as specified for American
                                                                                                                              Standard taper pipe threads.
                                                                     (2) Calculation for a cylinder must be                     (iii) Straight threads, having at least
                                                                    made by the following formula:                            4 engaged threads, to have tight fit and
                                                                    S = [P(1.3D 2 + 0.4d 2)] / (D 2 ¥ d 2)                    calculated shear strength at least 10
                                                                                                                              times the test pressure of the con-
                                                                    Where:                                                    tainer; gaskets required, adequate to
                                                                    S = wall stress in pounds psi;                            prevent leakage.
                                                                    P = test pressure prescribed for water jacket               (i) Hydrostatic test. Each cylinder
                                                                      test, i.e., at least 2 times service pressure,          must successfully withstand a hydro-
                                                                      in psig;
                                                                                                                              static test as follows:
                                                                    D = outside diameter in inches;
                                                                                                                                (1) The test must be by water-jacket,
                                                                    d = inside diameter in inches.
                                                                                                                              or other suitable method, operated so
                                                                      (g) Heat treatment. The completed                       as to obtain accurate data. The pres-
                                                                    containers must be uniformly and                          sure gauge must permit reading to an
                                                                    properly heat-treated prior to tests.                     accuracy of 1 percent. The expansion
                                                                    Heat-treatment of containers of the au-                   gauge must permit reading of total ex-
                                                                    thorized analysis must be as follows:                     pansion to accuracy either of 1 percent
                                                                      (1) All containers must be quenched                     or 0.1 cubic centimeter.
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                                                                    by oil, or other suitable medium except                     (2) Pressure must be maintained for
                                                                    as provided in paragraph (g)(4) of this                   at least 30 seconds and sufficiently
                                                                    section.                                                  longer to ensure complete expansion.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.58

                                                                    Any internal pressure applied after                         (1) A physical test for a sphere is re-
                                                                    heat-treatment and previous to the of-                    quired on 2 specimens cut from a flat
                                                                    ficial test may not exceed 90 percent of                  representative sample plate of the
                                                                    the test pressure. If, due to failure of                  same heat taken at random from the
                                                                    the test apparatus, the test pressure                     steel used to produce the sphere. This
                                                                    cannot be maintained, the test may be                     flat steel from which the 2 specimens
                                                                    repeated at a pressure increased by 10                    are to be cut must receive the same
                                                                    percent or 100 psig, whichever is the                     heat-treatment as the spheres them-
                                                                    lower.                                                    selves. Sample plates to be taken for
                                                                      (3) Permanent volumetric expansion                      each lot of 200 or less spheres.
                                                                    may not exceed 10 percent of total vol-                     (2) Specimens for spheres have a
                                                                    umetric expansion at test pressure.                       gauge length of 2 inches with a width
                                                                      (4) Each container must be tested to                    not over 11⁄2 inches, or a gauge length
                                                                    at least 2 times service pressure.                        at least 24 times thickness with a
                                                                      (j) Burst test. One container taken at                  width not over 6 times thickness is au-
                                                                    random out of 200 or less must be                         thorized when wall of sphere is not
                                                                    hydrostatically tested to destruction.                    over 3⁄16 inch thick.
                                                                    The rupture pressure must be included                       (3) A physical test for cylinders is re-
                                                                    as part of the inspector’s report.                        quired on 2 specimens cut from 1 cyl-
                                                                      (k) Flattening test. Spheres and cyl-                   inder taken at random out of each lot
                                                                    inders must be subjected to a flat-                       of 200 or less.
                                                                    tening test as follows:                                     (4) Specimens for cylinder must con-
                                                                      (1) Flattening test for spheres. One                    form to the following:
                                                                    sphere taken at random out of each lot                      (i) A gauge length of 8 inches with a
                                                                    of 200 or less must be subjected to a                     width not over 11⁄2 inches, a gauge
                                                                    flattening test as follows:                               length of 2 inches with a width not
                                                                      (i) The test must be performed after                    over 11⁄2 inches, a gauge length at least
                                                                    the hydrostatic test.                                     24 times thickness with a width not
                                                                      (ii) The test must be at the weld be-                   over 6 times thickness is authorized
                                                                    tween the parallel steel plates on a                      when a cylinder wall is not over 3⁄16
                                                                    press with a welded seam, at right an-                    inch thick.
                                                                    gles to the plates. Any projecting ap-                      (ii) The specimen, exclusive of grip
                                                                    purtenances may be cut off (by me-                        ends, may not be flattened. Grip ends
                                                                    chanical means only) prior to crushing.                   may be flattened to within 1 inch of
                                                                      (2) Flattening test for cylinders. One                  each end of the reduced section.
                                                                    cylinder taken at random out of each                        (iii) Heating of a specimen for any
                                                                    lot of 200 or less, must be subjected to                  purpose is not authorized.
                                                                    a flattening test as follows:                               (5) The yield strength in tension
                                                                      (i) The test must be performed after                    must be the stress corresponding to a
                                                                    the hydrostatic test.                                     permanent strain of 0.2 percent of the
                                                                      (ii) The test cylinder must be placed                   gauge length. The following conditions
                                                                    between wedge-shaped knife edges hav-                     apply:
                                                                    ing a 60° angle, rounded to a 1⁄2-inch ra-                  (i) The yield strength must be deter-
                                                                    dius.                                                     mined by either the ‘‘offset’’ method or
                                                                      (l) Radiographic inspection. Radio-                     the ‘‘extension under load’’ method as
                                                                    graphic examinations is required on all                   prescribed in ASTM E 8 (IBR, see § 171.7
                                                                    welded joints which are subjected to in-                  of this subchapter).
                                                                    ternal pressure, except that at the dis-                    (ii) In using the ‘‘extension under
                                                                    cretion of the disinterested inspector,                   load’’ method, the total strain (or ‘‘ex-
                                                                    openings less than 25 percent of the                      tension under load’’) corresponding to
                                                                    sphere diameter need not be subjected                     the stress at which the 0.2 percent per-
                                                                    to radiographic inspection. Evidence of                   manent strain occurs may be deter-
                                                                    any defects likely to seriously weaken                    mined with sufficient accuracy by cal-
                                                                    the container must be cause for rejec-                    culating the elastic extension of the
                                                                    tion.                                                     gauge length under appropriate load
                                                                      (m) Physical test and specimens for                     and adding thereto 0.2 percent of the
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                                                                    spheres and cylinders. Spheres and cyl-                   gauge length. Elastic extension cal-
                                                                    inders must be subjected to a physical                    culations must be based on an elastic
                                                                    test as follows:                                          modulus of 30,000,000. In the event of

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                                                                    § 178.59                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    controversy, the entire stress-strain                     quality must be used. Content percent
                                                                    diagram must be plotted and the yield                     may not exceed the following: Carbon,
                                                                    strength determined from the 0.2 per-                     0.25; phosphorus, 0.045; sulphur, 0.050.
                                                                    cent offset.                                                (c) Identification of steel. Materials
                                                                      (iii) For the purpose of strain meas-                   must be identified by any suitable
                                                                    urement, the initial strain must be set                   method except that plates and billets
                                                                    while the specimen is under a stress of                   for hot-drawn cylinders must be
                                                                    12,000 psi and the strain indicator read-                 marked with the heat number.
                                                                    ing being set at the calculated cor-                        (d) Manufacture. Cylinders must be
                                                                    responding strain.                                        manufactured using equipment and
                                                                      (iv) Cross-head speed of the testing                    processes adequate to ensure that each
                                                                    machine may not exceed 1⁄8 inch per                       cylinder produced conforms to the re-
                                                                    minute during yield strength deter-                       quirements of this subpart. No defect is
                                                                    mination.                                                 acceptable that is likely to weaken the
                                                                      (n) Acceptable results for physical, flat-              finished cylinder appreciably. A rea-
                                                                    tening, and burst tests. The following are                sonably smooth and uniform surface
                                                                    acceptable results of the physical, flat-                 finish is required. Welding procedures
                                                                    tening and burst test:                                    and operators must be qualified in ac-
                                                                      (1) Elongation must be at least 20                      cordance with CGA Pamphlet C–3 (IBR,
                                                                    percent for a 2-inch gauge length or 10                   see § 171.7 of this subchapter).
                                                                    percent in other cases.                                     (e) Exposed bottom welds. Exposed bot-
                                                                      (2) Flattening is required to 50 per-                   tom welds on cylinders over 18 inches
                                                                    cent of the original outside diameter                     long must be protected by footrings.
                                                                    without cracking.                                           (f) Heat treatment. Body and heads
                                                                      (3) Burst pressure must be at least 3                   formed by drawing or pressing must be
                                                                    times service pressure.                                   uniformly and properly heat treated
                                                                      (o) Rejected containers. Reheat-treat-                  prior to tests.
                                                                    ment of rejected cylinders is author-                       (g) Openings. Openings in the cyl-
                                                                    ized. Subsequent thereto, containers                      inders must comply with the following:
                                                                    must pass all prescribed tests to be ac-                    (1) Standard taper pipe threads are
                                                                    ceptable. Repair of welded seams by                       required;
                                                                    welding prior to reheat-treatment is                        (2) Length may not be less than as
                                                                    authorized.                                               specified for American Standard pipe
                                                                      (p) Marking. Markings on each con-                      threads; tapped to gauge; clean cut,
                                                                    tainer must be stamped plainly and                        even, and without checks.
                                                                    permanently on a permanent attach-                          (h) Hydrostatic test. Each cylinder
                                                                    ment or on a metal nameplate perma-                       must successfully withstand a hydro-
                                                                    nently secured to the container by                        static test as follows:
                                                                    means other than soft solder.                               (1) The test must be by water-jacket,
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as             or other suitable method, operated so
                                                                    amended at 66 FR 45386, 45388, Aug. 28, 2001;             as to obtain accurate data. The pres-
                                                                    67 FR 51654, Aug. 8, 2002; 67 FR 61015, Sept. 27,         sure gauge must permit reading to an
                                                                    2002; 68 FR 75748, Dec. 31, 2003]                         accuracy of 1 percent. The expansion
                                                                                                                              gauge must permit reading of total ex-
                                                                    § 178.59 Specification 8 steel cylinders                  pansion to an accuracy of either 1 per-
                                                                         with porous fillings for acetylene.                  cent or 0.1 cubic centimeter.
                                                                       (a) Type and service pressure. A DOT 8                   (2) Pressure must be maintained for
                                                                    cylinder is a seamless cylinder with a                    at least 30 seconds and sufficiently
                                                                    service pressure of 250 psig. The fol-                    longer to ensure complete expansion.
                                                                    lowing steel is authorized:                               Any internal pressure applied after
                                                                       (1) A longitudinal seam if forge lap                   heat-treatment and previous to the of-
                                                                    welded;                                                   ficial test may not exceed 90 percent of
                                                                       (2) Attachment of heads by welding                     the test pressure.
                                                                    or by brazing by dipping process; or                        (3) Permanent volumetric expansion
                                                                       (3) A welded circumferential body                      may not exceed 10 percent of total vol-
                                                                    seam if the cylinder has no longitu-                      umetric expansion at test pressure.
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                                                                    dinal seam.                                                 (4) One cylinder out of each lot of 200
                                                                       (b) Steel. Open-hearth, electric or                    or less must be hydrostatically tested
                                                                    basic oxygen process steel of uniform                     to at least 750 psig. Cylinders not so

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.59

                                                                    tested must be examined under pres-                         (iv) Cross-head speed of the testing
                                                                    sure of between 500 and 600 psig and                      machine may not exceed 1⁄8 inch per
                                                                    show no defect. If hydrostatically test-                  minute during yield strength deter-
                                                                    ed cylinder fails, each cylinder in the                   mination.
                                                                    lot may be hydrostatically tested and                       (4) Yield strength may not exceed 73
                                                                    those passing are acceptable.                             percent of tensile strength. Elongation
                                                                      (i) Leakage test. Cylinders with bot-                   must be at least 40 percent in 2 inch or
                                                                    toms closed in by spinning must be                        20 percent in other cases.
                                                                    subjected to a leakage test by setting                      (k) Rejected cylinders. Reheat treat-
                                                                    the interior air or gas pressure to not                   ment of rejected cylinder is authorized.
                                                                    less than the service pressure. Cyl-                      Subsequent thereto, cylinders must
                                                                    inders which leak must be rejected.                       pass all prescribed tests to be accept-
                                                                      (j) Physical test. A physical test must                 able. Repair by welding is authorized.
                                                                    be conducted as follows:                                    (l) Porous filling. (1) Cylinders must
                                                                      (1) The test is required on 2 speci-                    be filled with a porous material in ac-
                                                                    mens cut longitudinally from 1 cyl-                       cordance with the following:
                                                                    inder or part thereof taken at random                       (i) The porous material may not dis-
                                                                    out of each lot of 200 or less, after heat                integrate or sag when wet with solvent
                                                                    treatment.                                                or when subjected to normal service;
                                                                      (2) Specimens must conform to a
                                                                                                                                (ii) The porous filling material must
                                                                    gauge length of 8 inches with a width
                                                                                                                              be uniform in quality and free of voids,
                                                                    not over 11⁄2 inches, a gauge length of 2
                                                                                                                              except that a well drilled into the fill-
                                                                    inches with width not over 11⁄2, or a
                                                                                                                              ing material beneath the valve is au-
                                                                    gauge length at least 24 times thick-
                                                                                                                              thorized if the well is filled with a ma-
                                                                    ness with a width not over 6 times
                                                                                                                              terial of such type that the functions
                                                                    thickness is authorized when a cylinder
                                                                                                                              of the filling material are not im-
                                                                    wall is not over 3⁄16 inch thick.
                                                                                                                              paired;
                                                                      (3) The yield strength in tension
                                                                    must be the stress corresponding to a                       (iii) Overall shrinkage of the filling
                                                                    permanent strain of 0.2 percent of the                    material is authorized if the total
                                                                    gauge length. The following conditions                    clearance between the cylinder shell
                                                                    apply:                                                    and filling material, after solvent has
                                                                      (i) The yield strength must be deter-                   been added, does not exceed 1⁄2 of 1 per-
                                                                                                                              cent of the respective diameter or
                                                                    mined by either the ‘‘offset’’ method or
                                                                                                                              length, but not to exceed 1⁄8 inch, meas-
                                                                    the ‘‘extension under load’’ method as
                                                                                                                              ured diametrically and longitudinally;
                                                                    prescribed in ASTM E 8 (IBR, see § 171.7
                                                                    of this subchapter).                                        (iv) The clearance may not impair
                                                                      (ii) In using the ‘‘extension under                     the functions of the filling material;
                                                                    load’’ method, the total strain (or ‘‘ex-                   (v) The installed filling material
                                                                    tension under load’’) corresponding to                    must meet the requirements of CGA C–
                                                                    the stress at which the 0.2 percent per-                  12 (IBR, see § 171.7 of this subchapter);
                                                                    manent strain occurs may be deter-                        and
                                                                    mined with sufficient accuracy by cal-                      (vi) Porosity of filling material may
                                                                    culating the elastic extension of the                     not exceed 80 percent except that fill-
                                                                    gauge length under appropriate load                       ing material with a porosity of up to 92
                                                                    and adding thereto 0.2 percent of the                     percent may be used when tested with
                                                                    gauge length. Elastic extension cal-                      satisfactory results in accordance with
                                                                    culations must be based on an elastic                     CGA Pamphlet C–12.
                                                                    modulus of 30,000,000. In the event of                      (2) When the porosity of each cyl-
                                                                    controversy, the entire stress-strain                     inder is not known, a cylinder taken at
                                                                    diagram must be plotted and the yield                     random from a lot of 200 or less must
                                                                    strength determined from the 0.2 off-                     be tested for porosity. If the test cyl-
                                                                    set.                                                      inder fails, each cylinder in the lot
                                                                      (iii) For the purpose of strain meas-                   may be tested individually and those
                                                                    urement, the initial strain must be set                   cylinders that pass the test are accept-
                                                                    while the specimen is under a stress of                   able.
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                                                                    12,000 psi and the strain indicator read-                   (3) For filling that is molded and
                                                                    ing being set at the calculated cor-                      dried before insertion in cylinders, po-
                                                                    responding strain.                                        rosity test may be made on a sample

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                                                                    § 178.60                                                                                                  49 CFR Ch. I (10–1–09 Edition)

                                                                    block taken at random from material                                                           turer and three copies to the company
                                                                    to be used.                                                                                   that is to complete the cylinders.
                                                                      (4) The porosity of the filling mate-                                                         (4) Determine porosity of filling and
                                                                    rial must be determined. The amount                                                           tare weights; verify compliance of
                                                                    of solvent at 70 °F for a cylinder:                                                           marking with prescribed requirements;
                                                                      (i) Having shell volumetric capacity                                                        obtain necessary copies of steel shell
                                                                    above 20 pounds water capacity (nomi-                                                         reports; and furnish complete reports
                                                                    nal) may not exceed the following:                                                            required by this specification to the
                                                                                                                                                                  person who has completed the manu-
                                                                                                                                                    Maximum
                                                                                                                                                   acetone sol-   facture of the cylinders and, upon re-
                                                                                      Percent porosity of filler                                   vent percent   quest, to the purchaser. The test re-
                                                                                                                                                   shell capac-
                                                                                                                                                    ity by vol-   ports must be retained by the inspector
                                                                                                                                                        ume       for fifteen years from the original test
                                                                    90   to   92   .............................................................          43.4
                                                                                                                                                                  date of the cylinder.
                                                                    87   to   90   .............................................................          42.0      (o) Marking. (1) Marking on each cyl-
                                                                    83   to   87   .............................................................          40.0    inder must be stamped plainly and per-
                                                                    80   to   83   .............................................................          38.6
                                                                    75   to   80   .............................................................          36.2
                                                                                                                                                                  manently on or near the shoulder, top
                                                                    70   to   75   .............................................................          33.8    head, neck or valve protection collar
                                                                    65   to   70   .............................................................          31.4    which is permanently attached to the
                                                                                                                                                                  cylinder and forming integral part
                                                                      (ii) Having volumetric capacity of 20                                                       thereof.
                                                                    pounds or less water capacity (nomi-                                                            (2) Tare weight of cylinder, in pounds
                                                                    nal), may not exceed the following:                                                           and ounces, must be marked on the
                                                                                                                                                    Maximum
                                                                                                                                                                  cylinder.
                                                                                                                                                   acetone sol-     (3) Cylinders, not completed, when
                                                                                                                                                   vent percent   delivered must each be marked for
                                                                                      Percent porosity of filler                                   shell capac-
                                                                                                                                                    ity by vol-   identification of each lot of 200 or less.
                                                                                                                                                        ume
                                                                                                                                                                  [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    90   to   92   .............................................................          41.8    amended at 66 FR 45386, Aug. 28, 2001; 67 FR
                                                                    83   to   90   .............................................................          38.5    61016, Sept. 27, 2002; 67 FR 51654, Aug. 8, 2002;
                                                                    80   to   83   .............................................................          37.1
                                                                    75   to   80   .............................................................          34.8
                                                                                                                                                                  68 FR 75748, 75749, Dec. 31, 2003]
                                                                    70   to   75   .............................................................          32.5
                                                                    65   to   70   .............................................................          30.2    § 178.60 Specification 8AL steel cyl-
                                                                                                                                                                       inders with porous fillings for acet-
                                                                       (m) Tare weight. The tare weight is                                                             ylene.
                                                                    the combined weight of the cylinder                                                              (a) Type and service pressure. A DOT
                                                                    proper, porous filling, valve, and sol-                                                       8AL cylinder is a seamless steel cyl-
                                                                    vent, without removable cap.                                                                  inder with a service pressure of 250
                                                                       (n) Duties of inspector. In addition to                                                    psig. However, the attachment of heads
                                                                    the requirements of § 178.35, the inspec-                                                     by welding or by brazing by dipping
                                                                    tor is required to—                                                                           process and a welded circumferential
                                                                       (1) Certify chemical analyses of steel                                                     body seam is authorized. Longitudinal
                                                                    used, signed by manufacturer thereof;                                                         seams are not authorized.
                                                                    also verify by, check analyses of sam-                                                           (b) Authorized steel. The authorized
                                                                    ples taken from each heat or from 1 out                                                       steel is as specified in table I of appen-
                                                                    of each lot of 200 or less, plates, shells,                                                   dix A to this part.
                                                                    or tubes used.                                                                                   (c) Identification of steel. Material
                                                                       (2) Verify compliance of cylinder                                                          must be identified by any suitable
                                                                    shells with all shell requirements; in-                                                       method except that plates and billets
                                                                    spect inside before closing in both ends;                                                     for hot-drawn cylinders must be
                                                                    verify heat treatment as proper; obtain                                                       marked with heat number.
                                                                    all samples for all tests and for check                                                          (d) Manufacture. Cylinders must be
                                                                    analyses; witness all tests; verify                                                           manufactured using equipment and
                                                                    threads by gauge; report volumetric ca-                                                       processes adequate to ensure that each
                                                                    pacity and minimum thickness of wall                                                          cylinder produced conforms to the re-
                                                                    noted.                                                                                        quirements of this subpart. No defect is
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                                                                       (3) Prepare report on manufacture of                                                       permitted that is likely to weaken the
                                                                    steel shells in form prescribed in                                                            finished cylinder appreciably. A rea-
                                                                    § 178.35. Furnish one copy to manufac-                                                        sonably smooth and uniform surface

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.60

                                                                    finish is required. Welding procedures                      (3) For cylinders having outside di-
                                                                    and operators must be qualified in ac-                    ameter over 5 inches, the minimum
                                                                    cordance with CGA Pamphlet C–3 (IBR,                      wall thickness must be 0.087 inch.
                                                                    see § 171.7 of this subchapter).                            (h) Heat treatment. Each cylinder
                                                                       (e) Footrings. Exposed bottom welds                    must be uniformly and properly heat
                                                                    on cylinders over 18 inches long must                     treated, prior to tests, by any suitable
                                                                    be protected by footrings.                                method in excess of 1100 °F. Heat treat-
                                                                       (f) Welding or brazing. Welding or                     ment must be accomplished after all
                                                                    brazing for any purpose whatsoever is                     forming and welding operations, except
                                                                    prohibited except as follows:                             that when brazed joints are used, heat
                                                                       (1) The attachment to the tops or                      treatment must follow any forming
                                                                                                                              and welding operations but may be
                                                                    bottoms of cylinders of neckrings,
                                                                                                                              done before, during, or after the braz-
                                                                    footrings, handlers, bosses, pads, and
                                                                                                                              ing operations. Liquid quenching is not
                                                                    valve protecting rings is authorized
                                                                                                                              authorized.
                                                                    provided that such attachments and
                                                                                                                                (i) Openings. Standard taper pipe
                                                                    the portion of the container to which
                                                                                                                              threads required in all openings. The
                                                                    they are attached are made of weldable
                                                                                                                              length of the opening may not be less
                                                                    steel, the carbon content of which may
                                                                                                                              than as specified for American Stand-
                                                                    not exceed 0.25 percent.
                                                                                                                              ard pipe threads; tapped to gauge;
                                                                       (2) Heat treatment is not required                     clean cut, even, and without checks.
                                                                    after welding or brazing weldable low                       (j) Hydrostatic test. Each cylinder
                                                                    carbon parts to attachments, specified                    must successfully withstand a hydro-
                                                                    in paragraph (f)(1) of this section, of                   static test as follows:
                                                                    similar material which have been pre-                       (1) The test must be by water-jacket,
                                                                    viously welded or brazed to the top or                    or other suitable method, operated so
                                                                    bottom of cylinders and properly heat                     as to obtain accurate data. The pres-
                                                                    treated, provided such subsequent                         sure gauge must permit reading to an
                                                                    welding or brazing does not produce a                     accuracy of 1 percent. The expansion
                                                                    temperature in excess of 400 °F in any                    gauge must permit reading of total ex-
                                                                    part of the top or bottom material.                       pansion to an accuracy of either 1 per-
                                                                       (g) Wall thickness; wall stress. The wall              cent or 0.1 cubic centimeter.
                                                                    thickness/wall stress of the cylinder                       (2) Pressure must be maintained for
                                                                    must conform to the following:                            at least 30 seconds and sufficiently
                                                                       (1) The calculated wall stress at 750                  longer to ensure complete expansion.
                                                                    psi may not exceed 35,000 psi, or one-                    Any internal pressure applied after
                                                                    half of the minimum ultimate strength                     heat-treatment and previous to the of-
                                                                    of the steel as determined in paragraph                   ficial test may not exceed 90 percent of
                                                                    (l) of this section, whichever value is                   the test pressure.
                                                                    the smaller. The measured wall thick-                       (3) Permanent volumetric expansion
                                                                    ness may not include galvanizing or                       may not exceed 10 percent of total vol-
                                                                    other protective coating.                                 umetric expansion at test pressure.
                                                                       (i) Calculation of wall stress must be                   (4) One cylinder out of each lot of 200
                                                                    made by the formula:                                      or less must be hydrostatically tested
                                                                                                                              to at least 750 psig. Cylinders not so
                                                                    S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)                        tested must be examined under pres-
                                                                    Where:                                                    sure of between 500 and 600 psig and
                                                                    S = wall stress in pounds psi;
                                                                                                                              show no defect. If a hydrostatically
                                                                    P = 750 psig (minimum test pressure);                     tested cylinder fails, each cylinder in
                                                                    D = outside diameter in inches;                           the lot may be hydrostatically tested
                                                                    d = inside diameter in inches.                            and those passing are acceptable.
                                                                                                                                (k) Leakage test. Cylinders with bot-
                                                                      (ii) Either D or d must be calculated                   toms closed in by spinning must be
                                                                    from the relation D = d + 2t, where t =                   leakage tested by setting the interior
                                                                    minimum wall thickness.                                   air or gas pressure at not less than the
                                                                      (2) Cylinders with a wall thickness                     service pressure. Any cylinder that
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                                                                    less than 0.100 inch, the ratio of                        leaks must be rejected.
                                                                    straight side wall length to outside di-                    (l) Physical test. A physical test must
                                                                    ameter may not exceed 3.5.                                be conducted as follows;

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                                                                    § 178.60                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                      (1) The test is required on 2 speci-                    psi to a maximum of four such incre-
                                                                    mens cut longitudinally from 1 cyl-                       ments.
                                                                    inder or part thereof taken at random                       (n) Weld tests. Specimens taken
                                                                    out of each lot of 200 or less, after heat                across the circumferentially welded
                                                                    treatment.                                                seam must be cut from one cylinder
                                                                      (2) Specimens must conform to a                         taken at random from each lot of 200 or
                                                                    gauge length of 8 inches with a width                     less cylinders after heat treatment and
                                                                    not over 11⁄2 inches, a gauge length 2                    must pass satisfactorily the following
                                                                    inches with a width not over 11⁄2 inches,                 tests:
                                                                    or a gauge length at least 24 times                         (1) Tensile test. A specimen must be
                                                                    thickness with a width not over 6 times                   cut from one cylinder of each lot of 200
                                                                    thickness is authorized when a cylinder                   or less, or welded test plate. The speci-
                                                                    wall is not over 3⁄16 inch thick.                         men must be taken from across the
                                                                      (3) The yield strength in tension                       major seam and must be prepared and
                                                                    must be the stress corresponding to a                     tested in accordance with and must
                                                                    permanent strain of 0.2 percent of the                    meet the requirements of CGA Pam-
                                                                    gauge length. The following conditions                    phlet C–3. Should this specimen fail to
                                                                    apply:                                                    meet the requirements, specimens may
                                                                      (i) The yield strength must be deter-                   be taken from two additional cylinders
                                                                                                                              or welded test plates from the same lot
                                                                    mined by either the ‘‘offset’’ method or
                                                                                                                              and tested. If either of the latter speci-
                                                                    the ‘‘extension under load’’ method as
                                                                                                                              mens fail to meet the requirements,
                                                                    prescribed in ASTM E 8 (IBR, see § 171.7
                                                                                                                              the entire lot represented must be re-
                                                                    of this subchapter).
                                                                                                                              jected.
                                                                      (ii) In using the ‘‘extension under                       (2) Guided bend test. A root bend test
                                                                    load’’ method, the total strain (or ‘‘ex-                 specimen must be cut from the cyl-
                                                                    tension under load’’) corresponding to                    inder or welded test plate, used for the
                                                                    the stress at which the 0.2 percent per-                  tensile test specified in paragraph
                                                                    manent strain occurs may be deter-                        (n)(1) of this section. Specimens must
                                                                    mined with sufficient accuracy by cal-                    be prepared and tested in accordance
                                                                    culating the elastic extension of the                     with and must meet the requirements
                                                                    gauge length under appropriate load                       of CGA Pamphlet C–3.
                                                                    and adding thereto 0.2 percent of the                       (3) Alternate guided-bend test. This
                                                                    gauge length. Elastic extension cal-                      test may be used and must be as re-
                                                                    culations must be based on an elastic                     quired by CGA Pamphlet C–3. The spec-
                                                                    modulus of 30,000,000. In the event of                    imen must be bent until the elongation
                                                                    controversy, the entire stress-strain                     at the outer surface, adjacent to the
                                                                    diagram must be plotted and the yield                     root of the weld, between the lightly
                                                                    strength determined from the 0.2 off-                     scribed gage lines-a to b, must be at
                                                                    set.                                                      least 20 percent, except that this per-
                                                                      (iii) For the purpose of strain meas-                   centage may be reduced for steels hav-
                                                                    urement, the initial strain must be set                   ing a tensile strength in excess of 50,000
                                                                    while the specimen is under a stress of                   psi, as provided in paragraph (m) of
                                                                    12,000 psi, the strain indicator reading                  this section.
                                                                    being set at the calculated cor-                            (o) Rejected cylinders. Reheat treat-
                                                                    responding strain.                                        ment of rejected cylinders is author-
                                                                      (iv) Cross-head speed of the testing                    ized. Subsequent thereto, cylinders
                                                                    machine may not exceed 1⁄8 inch per                       must pass all prescribed tests to be ac-
                                                                    minute during yield strength deter-                       ceptable. Repair by welding is author-
                                                                    mination.                                                 ized.
                                                                      (m) Elongation. Physical test speci-                      (p) Porous filling. (1) Cylinders must
                                                                    mens must show at least a 40 percent                      be filled with a porous material in ac-
                                                                    elongation for a 2 inch gauge length or                   cordance with the following:
                                                                    at least a 20 percent elongation in                         (i) The porous material may not dis-
                                                                    other cases. Except that these elon-                      integrate or sag when wet with solvent
                                                                    gation percentages may be reduced nu-                     or when subjected to normal service;
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                                                                    merically by 2 for 2 inch specimens and                     (ii) The filling material must be uni-
                                                                    1 in other cases for each 7,500 psi incre-                form in quality and free of voids, ex-
                                                                    ment of tensile strength above 50,000                     cept that a well drilled into the filling

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                                                                       § 178.60

                                                                    material beneath the valve is author-                                                                                                            Maximum acetone
                                                                                                                                                                   Percent porosity of filler                       solvent percent shell
                                                                    ized if the well is filled with a material                                                                                                       capacity by volume
                                                                    of such type that the functions of the
                                                                                                                                                         90   to   92   .........................................                     41.8
                                                                    filling material are not impaired;                                                   83   to   90   .........................................                     38.5
                                                                       (iii) Overall shrinkage of the filling                                            80   to   83   .........................................                     37.1
                                                                    material is authorized if the total                                                  75   to   80   .........................................                     34.8
                                                                                                                                                         70   to   75   .........................................                     32.5
                                                                    clearance between the cylinder shell                                                 65   to   70   .........................................                     30.2
                                                                    and filling material, after solvent has
                                                                    been added, does not exceed 1⁄2 of 1 per-                                              (q) Tare weight. The tare weight is
                                                                    cent of the respective diameter or                                                   the combined weight of the cylinder
                                                                    length but not to exceed 1⁄8 inch, meas-                                             proper, porous filling, valve, and sol-
                                                                    ured diametrically and longitudinally;                                               vent, but without removable cap.
                                                                       (iv) The clearance may not impair                                                   (r) Duties of inspector. In addition to
                                                                    the functions of the filling material;                                               the requirements of § 178.35, the inspec-
                                                                       (v) The installed filling material                                                tor shall—
                                                                    must meet the requirements of CGA C–                                                   (1) Certify chemical analyses of steel
                                                                                                                                                         used, signed by manufacturer thereof;
                                                                    12 (IBR, see § 171.7 of this subchapter);
                                                                                                                                                         also verify by check analyses, of sam-
                                                                    and
                                                                                                                                                         ples taken from each heat or from 1 out
                                                                       (vi) Porosity of filling material may                                             of each lot of 200 or less plates, shells,
                                                                    not exceed 80 percent except that fill-                                              or tubes used.
                                                                    ing material with a porosity of up to 92                                               (2) Verify compliance of cylinder
                                                                    percent may be used when tested with                                                 shells with all shell requirements, in-
                                                                    satisfactory results in accordance with                                              spect inside before closing in both ends,
                                                                    CGA Pamphlet C–12.                                                                   verify heat treatment as proper; obtain
                                                                       (2) When the porosity of each cyl-                                                all samples for all tests and for check
                                                                    inder is not known, a cylinder taken at                                              analyses, witness all tests; verify
                                                                    random from a lot of 200 or less must                                                threads by gauge, report volumetric ca-
                                                                    be tested for porosity. If the test cyl-                                             pacity and minimum thickness of wall
                                                                    inder fails, each cylinder in the lot                                                noted.
                                                                    may be tested individually and those                                                   (3) Report percentage of each speci-
                                                                    cylinders that pass the test are accept-                                             fied alloying element in the steel. Pre-
                                                                    able.                                                                                pare report on manufacture of steel
                                                                                                                                                         shells in form prescribed in § 178.35.
                                                                       (3) For filling that is molded and
                                                                                                                                                         Furnish one copy to manufacturer and
                                                                    dried before insertion in cylinders, po-                                             three copies to the company that is to
                                                                    rosity test may be made on sample                                                    complete the cylinders.
                                                                    block taken at random from material                                                    (4) Determine porosity of filling and
                                                                    to be used.                                                                          tare weights; verify compliance of
                                                                       (4) The porosity of the filling mate-                                             marking with prescribed requirements;
                                                                    rial must be determined; the amount of                                               obtain necessary copies of steel shell
                                                                    solvent at 70 °F for a cylinder:                                                     reports prescribed in paragraph (b) of
                                                                       (i) Having shell volumetric capacity                                              this section; and furnish complete test
                                                                    above 20 pounds water capacity (nomi-                                                reports required by this specification
                                                                    nal) may not exceed the following:                                                   to the person who has completed the
                                                                                                                                                         manufacturer of the cylinders and,
                                                                                                                                Maximum acetone          upon request, to the purchaser. The
                                                                              Percent porosity of filler                       solvent percent shell
                                                                                                                                capacity by volume       test reports must be retained by the in-
                                                                                                                                                         spector for fifteen years from the origi-
                                                                    90   to   92   .........................................                     43.4
                                                                                                                                                         nal test date of the cylinder.
                                                                    87   to   90   .........................................                     42.0
                                                                    83   to   87   .........................................                     40.0
                                                                                                                                                           (s) Marking. (1) Tare weight of cyl-
                                                                    80   to   83   .........................................                     38.6    inder, in pounds and ounces, must be
                                                                    75   to   80   .........................................                     36.2    marked on the cylinder.
                                                                    70   to   75   .........................................                     33.8      (2) Cylinders, not completed, when
                                                                    65   to   70   .........................................                     31.4    delivered must each be marked for
                                                                                                                                                         identification of each lot of 200 or less.
                                                                      (ii) Having volumetric capacity of 20
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                                                                                                                                                           (3) Markings must be stamped plainly
                                                                    pounds or less water capacity (nomi-                                                 and permanently in locations in ac-
                                                                    nal), may not exceed the following:                                                  cordance with the following:

                                                                                                                                                       875



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                                                                    § 178.61                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                      (i) On shoulders and top heads not                      processes adequate to ensure that each
                                                                    less than 0.087 inch thick; or                            cylinder produced conforms to the re-
                                                                      (ii) On neck, valve boss, valve protec-                 quirements of this subpart and the fol-
                                                                    tion sleeve, or similar part perma-                       lowing:
                                                                    nently attached to the top end of cyl-                       (1) No defect is permitted that is
                                                                    inder; or                                                 likely to weaken the finished cylinder
                                                                      (iii) On a plate of ferrous material at-                appreciably. A reasonably smooth and
                                                                    tached to the top of the cylinder or                      uniform surface is required. Exposed
                                                                    permanent part thereof; the plate must                    bottom welds on cylinders over 18
                                                                    be at least 1⁄16 inch thick, and must be                  inches long must be protected by
                                                                    attached by welding, or by brazing at a                   footrings. Minimum thickness of heads
                                                                    temperature of at least 1,100 °F                          may not be less than 90 percent of the
                                                                    throughout all edges of the plate. Suffi-                 required thickness of the sidewall.
                                                                    cient space must be left on the plate to                  Heads must be concave to pressure.
                                                                    provide for stamping at least four (4)                       (2) Circumferential seams must be by
                                                                    retest dates.                                             electric-arc welding. Joints must be
                                                                                                                              butt with one member offset (joggle
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    amended at 66 FR 45386, 45388, Aug. 28, 2001;             butt) or lap with minimum overlap of
                                                                    67 FR 51654, Aug. 8, 2002; 68 FR 75748, 75749,            at least four times nominal sheet
                                                                    Dec. 31, 2003]                                            thickness.
                                                                                                                                 (3) Longitudinal seams in shells must
                                                                    § 178.61 Specification      4BW     welded                conform to the following:
                                                                         steel cylinders with electric-arc                       (i) Longitudinal electric-arc welded
                                                                         welded longitudinal seam.                            seams must be of the butt welded type.
                                                                       (a) Type, size and service pressure. A                 Welds must be made by a machine
                                                                    DOT 4BW cylinder is a welded type                         process including automatic feed and
                                                                    steel cylinder with a longitudinal elec-                  welding guidance mechanisms. Longi-
                                                                    tric-arc welded seam, a water capacity                    tudinal seams must have complete
                                                                    (nominal) not over 1,000 pounds and a                     joint penetration, and must be free
                                                                    service pressure at least 225 and not                     from undercuts, overlaps or abrupt
                                                                    over 500 psig gauge. Cylinders closed in                  ridges or valleys. Misalignment of mat-
                                                                    by spinning process are not authorized.                   ing butt edges may not exceed 1⁄6 of
                                                                       (b) Authorized steel. Steel used in the                nominal sheet thickness or 1⁄32 inch
                                                                    construction of the cylinder must con-                    whichever is less. All joints with nomi-
                                                                    form to the following:                                    nal sheet thickness up to and including
                                                                       (1) The body of the cylinder must be                   1⁄8 inch must be tightly butted. When

                                                                    constructed of steel conforming to the                    nominal sheet thickness is greater
                                                                    limits specified in table 1 of appendix A                 than 1⁄8 inch, the joint must be gapped
                                                                    to this part.                                             with maximum distance equal to one-
                                                                       (2) Material for heads must meet the                   half the nominal sheet thickness or 1⁄32
                                                                    requirements of paragraph (a) of this                     inch whichever is less. Joint design,
                                                                    section or be open hearth, electric or                    preparation and fit-up must be such
                                                                    basic oxygen carbon steel of uniform                      that requirements of this paragraph (d)
                                                                    quality. Content percent may not ex-                      are satisfied.
                                                                    ceed the following: Carbon 0.25, Man-                        (ii) Maximum joint efficiency must
                                                                    ganese 0.60, Phosphorus 0.045, Sulfur                     be 1.0 when each seam is radiographed
                                                                    0.050. Heads must be hemispherical or                     completely. Maximum joint efficiency
                                                                    ellipsoidal in shape with a maximum                       must be 0.90 when one cylinder from
                                                                    ratio of 2.1. If low carbon steel is used,                each lot of 50 consecutively welded cyl-
                                                                    the thickness of such heads must be de-                   inders is spot radiographed. In addi-
                                                                    termined by using a maximum wall                          tion, one out of the first five cylinders
                                                                    stress of 24,000 p.s.i. in the formula de-                welded following a shut down of weld-
                                                                    scribed in paragraph (f)(4) of this sec-                  ing operations exceeding four hours
                                                                    tion.                                                     must be spot radiographed. Spot
                                                                       (c) Identification of material. Material               radiographs, when required, must be
                                                                    must be identified by any suitable                        made of a finished welded cylinder and
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                                                                    method.                                                   must include the girth weld for 2
                                                                       (d) Manufacture. Cylinders must be                     inches in both directions from the
                                                                    manufactured using equipment and                          intersection of the longitudinal and

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.61

                                                                    girth welds and include at least 6                        have been previously welded to the top
                                                                    inches of the longitudinal weld. Max-                     or bottom of cylinders and properly
                                                                    imum joint efficacy of 0.75 must be per-                  heat treated, provided such subsequent
                                                                    missible without radiography.                             welding or brazing does not produce a
                                                                      (4) Welding procedures and operators                    temperature in excess of 400 °F in any
                                                                    must be qualified in accordance with                      part of the top or bottom material.
                                                                    CGA Pamphlet C–3 (IBR, see § 171.7 of                        (h) Openings in cylinders. Openings in
                                                                    this subchapter).                                         the cylinder must conform to the fol-
                                                                      (e) Welding of attachments. The at-                     lowing:
                                                                    tachment to the tops and bottoms only                        (1) All openings must be in the heads
                                                                    of cylinders by welding of neckrings,                     or bases.
                                                                    footrings, handles, bosses, pads and                         (2) Openings in cylinders must be pro-
                                                                    valve protection rings is authorized                      vided with adequate fittings, bosses, or
                                                                    provided that such attachments and                        pads, integral with or securely at-
                                                                    the portion of the container to which                     tached to the cylinder by welding.
                                                                    they are attached are made of weldable                       (3) Threads must comply with the fol-
                                                                    steel, the carbon content of which may                    lowing:
                                                                    not exceed 0.25 percent.                                     (i) Threads must be clean cut and to
                                                                      (f) Wall thickness. For outside diame-                  gauge.
                                                                    ters over 6 inches the minimum wall                          (ii) Taper threads must be of length
                                                                    thickness must be 0.078 inch. For a cyl-                  not less than as specified for American
                                                                    inder with a wall thickness less than                     Standard Taper Pipe threads.
                                                                    0.100 inch, the ratio of tangential                          (iii) Straight threads, having at least
                                                                    length to outside diameter may not ex-                    4 engaged threads, to have tight fit and
                                                                    ceed 4 to1 (4:1). In any case the min-                    calculated shear strength at least 10
                                                                    imum wall thickness must be such that                     times the test pressure of the cylinder;
                                                                    the wall stress calculated by the for-                    gaskets required, adequate to prevent
                                                                    mula listed in paragraph (f)(4) of this                   leakage.
                                                                    section may not exceed the lesser value                      (4) Closure of fittings, boss or pads
                                                                    of any of the following:                                  must be adequate to prevent leakage.
                                                                      (1) The value referenced in paragraph                      (i) Hydrostatic test. Cylinders must
                                                                    (b) of this section for the particular                    withstand a hydrostatic test, as fol-
                                                                    material under consideration.                             lows:
                                                                      (2) One-half of the minimum tensile                        (1) The test must be by water-jacket,
                                                                    strength of the material determined as                    or other suitable method, operated so
                                                                    required in paragraph (j) of this sec-                    as to obtain accurate data. The pres-
                                                                    tion.                                                     sure gauge must permit readings to an
                                                                      (3) 35,000 psi.                                         accuracy of 1 percent. The expansion
                                                                      (4) Stress must be calculated by the                    gauge must permit readings of total
                                                                    following formula:                                        volumetric expansion to an accuracy
                                                                                                                              either of 1 percent or 0.1 cubic centi-
                                                                    S = [2P(1.3D2 + 0.4d2)] / [E(D2 ¥ d2)]
                                                                                                                              meter.
                                                                    where:                                                       (2) Pressure must be maintained for
                                                                    S = wall stress, psi;                                     at least 30 seconds and sufficiently
                                                                    P = service pressure, psig;                               longer to ensure complete expansion.
                                                                    D = outside diameter, inches;                             Any internal pressure applied after
                                                                    d = inside diameter, inches;                              heat treatment and previous to the of-
                                                                    E = joint efficiency of the longitudinal seam             ficial test may not exceed 90 percent of
                                                                      (from paragraph (d) of this section).
                                                                                                                              the test pressure.
                                                                      (g) Heat treatment. Each cylinder                          (3) Permanent volumetric expansion
                                                                    must be uniformly and properly heat                       may not exceed 10 percent of the total
                                                                    treated prior to test by the applicable                   volumetric expansion at test pressure.
                                                                    method referenced in Table 1 of appen-                       (4) Cylinders must be tested as fol-
                                                                    dix A to this part. Heat treatment                        lows:
                                                                    must be accomplished after all forming                       (i) At least 1 cylinder selected at ran-
                                                                    and welding operations. Heat treat-                       dom out of each lot of 200 or less must
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                                                                    ment is not required after welding or                     be tested as outlined in paragraphs
                                                                    brazing of weldable low carbon parts to                   (i)(1), (i)(2), and (i)(3) of this section to
                                                                    attachments of similar material which                     at least two times service pressure.

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                                                                    § 178.61                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                      (ii) All cylinders not tested as out-                      (iv) Heating of a specimen for any
                                                                    lined in paragraph (i)(4)(i) of this sec-                 purpose is not authorized.
                                                                    tion must be examined under pressure                         (3) The yield strength in tension
                                                                    of at least two times service pressure                    must be the stress corresponding to a
                                                                    and show no defect.                                       permanent strain of 0.2 percent of the
                                                                      (5) One finished cylinder selected at                   gauge length. The following conditions
                                                                    random out of each lot of 500 or less                     apply:
                                                                    successively      produced    must     be                    (i) The yield strength must be deter-
                                                                    hydrostatically tested to 4 times serv-                   mined by either the ‘‘off-set’’ method
                                                                    ice pressure without bursting.                            or the ‘‘extension under load’’ method
                                                                      (j) Physical tests. Cylinders must be                   as prescribed in ASTM E 8 (IBR, see
                                                                    subjected to a physical test as follows:                  § 171.7 of this subchapter).
                                                                      (1) Specimens must be taken from                           (ii) In using the ‘‘extension under
                                                                    one cylinder after heat treatment and                     load’’ method, the total strain (or ‘‘ex-
                                                                    chosen at random from each lot of 200                     tension under load’’), corresponding to
                                                                    or less, as follows:                                      the stress at which the 0.2-percent per-
                                                                                                                              manent strain occurs may be deter-
                                                                      (i) Body specimen. One specimen
                                                                                                                              mined with sufficient accuracy by cal-
                                                                    must be taken longitudinally from the
                                                                                                                              culating the elastic extension of the
                                                                    body section at least 90 degrees away
                                                                                                                              gauge length under appropriate load
                                                                    from the weld.
                                                                                                                              and adding thereto 0.2 percent of the
                                                                      (ii) Head specimen. One specimen                        gauge length. Elastic extension cal-
                                                                    must be taken from either head on a                       culations must be based on an elastic
                                                                    cylinder when both heads are made of                      modulus of 30,000,000. In the event of
                                                                    the same material. However, if the two                    controversy, the entire stress-strain
                                                                    heads are made of differing materials,                    diagram must be plotted and the yield
                                                                    a specimen must be taken from each                        strength determined from the 0.2-per-
                                                                    head.                                                     cent offset.
                                                                      (iii) If due to welded attachments on                      (iii) For the purpose of strain meas-
                                                                    the top head there is insufficient sur-                   urement, the initial strain reference
                                                                    face from which to take a specimen, it                    must be set while the specimen is
                                                                    may be taken from a representative                        under a stress of 12,000 psi and the
                                                                    head of the same heat treatment as the                    strain indicator reading being set at
                                                                    test cylinder.                                            the calculated corresponding strain.
                                                                      (2) Specimens must conform to the                          (iv) Cross-head speed of the testing
                                                                    following:                                                machine may not exceed 1⁄8 inch per
                                                                      (i) A gauge length of 8 inches with a                   minute during yield strength deter-
                                                                    width not over 11⁄2 inches, a gauge                       mination.
                                                                    length of 2 inches with a width not                          (k) Elongation. Physical test speci-
                                                                    over 11⁄2 inches, or a gauge length at                    mens must show at least a 40 percent
                                                                    least 24 times thickness with a width                     elongation for a 2-inch gauge length or
                                                                    not over 6 times thickness is author-                     at least a 20 percent elongation in
                                                                    ized when a cylinder wall is not over 3⁄16                other cases. Except that these elon-
                                                                    inch thick.                                               gation percentages may be reduced nu-
                                                                      (ii) The specimen, exclusive of grip                    merically by 2 for 2-inch specimens and
                                                                    ends, may not be flattened. Grip ends                     by 1 in other cases for each 7,500 psi in-
                                                                    may be flattened to within 1 inch of                      crement of tensile strength above 50,000
                                                                    each end of the reduced section.                          psi to a maximum of four increments.
                                                                      (iii) When size of the cylinder does                       (l) Tests of welds. Welds must be sub-
                                                                    not permit securing straight speci-                       jected to the following tests:
                                                                    mens, the specimens may be taken in                          (1) Tensile test. A specimen must be
                                                                    any location or direction and may be                      cut from one cylinder of each lot of 200
                                                                    straightened or flattened cold, by pres-                  or less. The specimen must be taken
                                                                    sure only, not by blows when speci-                       from across the longitudinal seam and
                                                                    mens are so taken and prepared, the in-                   must be prepared and tested in accord-
                                                                    spector’s report must show in connec-                     ance with and must meet the require-
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                                                                    tion with record of physical tests de-                    ments of CGA Pamphlet C–3.
                                                                    tailed information in regard to such                         (2) Guided bend test. A root test speci-
                                                                    specimens.                                                men must be cut from the cylinder

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.65

                                                                    used for the tensile test specified in                      (1) On shoulders and top heads when
                                                                    paragraph (l)(1) of this section. Speci-                  they are not less than 0.087-inch thick.
                                                                    mens must be taken from across the                          (2) On a metal plate attached to the
                                                                    longitudinal seam and must be pre-                        top of the cylinder or permanent part
                                                                    pared and tested in accordance with                       thereof; sufficient space must be left on
                                                                    and must meet the requirements of                         the plate to provide for stamping at
                                                                    CGA Pamphlet C–3.                                         least six retest dates; the plate must be
                                                                      (3) Alternate guided bend test. This                    at least 1⁄16-inch thick and must be at-
                                                                    test may be used and must be as re-                       tached by welding, or by brazing. The
                                                                    quired by CGA Pamphlet C–3. The spec-                     brazing rod is to melt at a temperature
                                                                    imen must be bent until the elongation                    of 1100 °F Welding or brazing must be
                                                                    at the outer surface, adjacent to the                     along all the edges of the plate.
                                                                    root of the weld, between the lightly                       (3) On the neck, valve boss, valve pro-
                                                                    scribed gauge lines a to b, must be at                    tection sleeve, or similar part perma-
                                                                    least 20 percent, except that this per-                   nently attached to the top of the cyl-
                                                                    centage may be reduced for steels hav-                    inder.
                                                                    ing a tensile strength in excess of 50,000                  (4) On the footring permanently at-
                                                                    psi, as provided in paragraph (k) of this                 tached to the cylinder, provided the
                                                                    section.                                                  water capacity of the cylinder does not
                                                                      (m) Radiographic examination. Welds                     exceed 25 pounds.
                                                                    of the cylinders must be subjected to a                     (p) Inspector’s report. In addition to
                                                                    radiographic examination as follows:                      the information required by § 178.35, the
                                                                                                                              inspector’s report must indicate the
                                                                      (1) Radiographic inspection must
                                                                                                                              type and amount of radiography.
                                                                    conform to the techniques and accept-
                                                                    ability criteria set forth in CGA Pam-                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as
                                                                    phlet C–3. When fluoroscopic inspection                   amended at 64 FR 51919, Sept. 27, 1999; 66 FR
                                                                    is used, permanent film records need                      45386, 45388, Aug. 28, 2001; 67 FR 51654, Aug. 6,
                                                                                                                              2002; 67 FR 61016, Sept. 27, 2002; 68 FR 57633,
                                                                    not be retained.
                                                                                                                              Oct. 6, 2003; 68 FR 75748, Dec. 31, 2003]
                                                                      (2) Should spot radiographic exam-
                                                                    ination fail to meet the requirements                     § 178.65 Specification 39 non-reusable
                                                                    of paragraph (m)(1) of this section, two                       (non-refillable) cylinders.
                                                                    additional welds from the same lot of                        (a) Type, size, service pressure, and test
                                                                    50 cylinders or less must be examined,                    pressure. A DOT 39 cylinder is a seam-
                                                                    and if either of these fail to meet the                   less, welded, or brazed cylinder with a
                                                                    requirements, each cylinder must be                       service pressure not to exceed 80 per-
                                                                    examined as previously outlined; only                     cent of the test pressure. Spherical
                                                                    those passing are acceptable.                             pressure vessels are authorized and
                                                                      (n) Rejected cylinders. (1) Unless oth-                 covered by references to cylinders in
                                                                    erwise stated, if a sample cylinder or                    this specification.
                                                                    specimen taken from a lot of cylinders                       (1) Size limitation. Maximum water ca-
                                                                    fails the prescribed test, then two addi-                 pacity may not exceed: (i) 55 pounds
                                                                    tional specimens must be selected from                    (1,526 cubic inches) for a service pres-
                                                                    the same lot and subjected to the pre-                    sure of 500 p.s.i.g. or less, and (ii) 10
                                                                    scribed test. If either of these fails the                pounds (277 cubic inches) for a service
                                                                    test, then the entire lot must be re-                     pressure in excess of 500 p.s.i.g.
                                                                    jected.                                                      (2) Test pressure. The minimum test
                                                                      (2) Reheat treatment of rejected cyl-                   pressure is the maximum pressure of
                                                                    inders is authorized. Subsequent there-                   contents at 130 °F or 180 p.s.i.g. which-
                                                                    to, cylinders must pass all prescribed                    ever is greater.
                                                                    tests to be acceptable. Repair of welded                     (3) Pressure of contents. The term
                                                                    seams by welding is authorized pro-                       ‘‘pressure of contents’’ as used in this
                                                                    vided that all defective metal is cut                     specification means the total pressure
                                                                    away and the joint is rewelded as pre-                    of all the materials to be shipped in the
                                                                    scribed for original welded joints.                       cylinder.
                                                                      (o) Markings. Markings must be                             (b) Material; steel or aluminum. The
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                                                                    stamped plainly and permanently in                        cylinder must be constructed of either
                                                                    any of the following locations on the                     steel or aluminum conforming to the
                                                                    cylinder:                                                 following requirements:

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                                                                    § 178.65                                                                           49 CFR Ch. I (10–1–09 Edition)

                                                                      (1) Steel. (i) The steel analysis must                               times the minimum strength of the
                                                                    conform to the following:                                              shell wall.
                                                                                                                                             (vi) Welded seams must be properly
                                                                                                                      Ladle      Check
                                                                                                                     analysis   analysis   aligned and welded by a method that
                                                                                                                                           provides clean, uniform joints with
                                                                    Carbon, maximum percent ....................         0.12       0.15   adequate penetration.
                                                                    Phosphorus, maximum percent .............             .04        .05
                                                                    Sulfur, maximum percent ......................        .05        .06     (vii) Welded joints must have a
                                                                                                                                           strength equal to or greater than the
                                                                      (ii) For a cylinder made of seamless                                 minimum strength of the shell mate-
                                                                    steel tubing with integrally formed                                    rial in the finished cylinder.
                                                                    ends, hot drawn, and finished, content                                   (3) Attachments to the cylinder are
                                                                    percent for the following may not ex-                                  permitted by any means which will not
                                                                    ceed: Carbon, 0.55; phosphorous, 0.045;                                be detrimental to the integrity of the
                                                                    sulfur, 0.050.                                                         cylinder. Welding or brazing of attach-
                                                                      (iii) For non-heat treated welded                                    ments to the cylinder must be com-
                                                                    steel cylinders, adequately killed deep                                pleted prior to all pressure tests.
                                                                    drawing quality steel is required.                                       (4) Welding procedures and operators
                                                                      (iv) Longitudinal or helical welded                                  must be qualified in accordance with
                                                                    cylinders are not authorized for service                               CGA Pamphlet C–3 (IBR, see § 171.7 of
                                                                    pressures in excess of 500 p.s.i.g.                                    this subchapter).
                                                                      (2) Aluminum. Aluminum is not au-                                      (d) Wall thickness. The minimum wall
                                                                    thorized for service pressures in excess                               thickness must be such that the wall
                                                                    of 500 psig. The analysis of the alu-                                  stress at test pressure does not exceed
                                                                    minum must conform to the Aluminum                                     the yield strength of the material of
                                                                    Association standard for alloys 1060,                                  the finished cylinder wall. Calculations
                                                                    1100, 1170, 3003, 5052, 5086, 5154, 6061, and                          must be made by the following for-
                                                                    6063, as specified in its publication en-                              mulas:
                                                                    titled ‘‘Aluminum Standards and                                          (1) Calculation of the stress for cyl-
                                                                    Data’’ (IBR, see § 171.7 of this sub-                                  inders must be made by the following
                                                                    chapter).                                                              formula:
                                                                      (3) Material with seams, cracks, lam-                                S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)
                                                                    inations, or other injurious defects not
                                                                    permitted.                                                             Where:
                                                                      (4) Material used must be identified                                 S = Wall stress, in psi;
                                                                    by any suitable method.                                                P = Test pressure in psig;
                                                                                                                                           D = Outside diameter, in inches;
                                                                      (c) Manufacture. (1) General manufac-
                                                                                                                                           d = Inside diameter, in inches.
                                                                    turing requirements are as follows:
                                                                      (i) The surface finish must be uni-                                    (2) Calculation of the stress for
                                                                    form and reasonably smooth.                                            spheres must be made by the following
                                                                      (ii) Inside surfaces must be clean,                                  formula:
                                                                    dry, and free of loose particles.                                      S = PD / 4t
                                                                      (iii) No defect of any kind is per-
                                                                    mitted if it is likely to weaken a fin-                                Where:
                                                                    ished cylinder.                                                        S = Wall stress, in psi;
                                                                      (2) Requirements for seams:                                          P = Test pressure i psig;
                                                                      (i) Brazing is not authorized on alu-                                D = Outside diameter, in inches;
                                                                                                                                           t = Minimum wall thickness, in inches.
                                                                    minum cylinders.
                                                                      (ii) Brazing material must have a                                      (e) Openings and attachments. Open-
                                                                    melting point of not lower than 1,000                                  ings and attachments must conform to
                                                                    °F.                                                                    the following:
                                                                      (iii) Brazed seams must be assembled                                   (1) Openings and attachments are
                                                                    with proper fit to ensure complete pen-                                permitted on heads only.
                                                                    etration of the brazing material                                         (2) All openings and their reinforce-
                                                                    throughout the brazed joint.                                           ments must be within an imaginary
                                                                      (iv) Minimum width of brazed joints                                  circle, concentric to the axis of the cyl-
                                                                    must be at least four times the thick-                                 inder. The diameter of the circle may
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                                                                    ness of the shell wall.                                                not exceed 80 percent of the outside di-
                                                                      (v) Brazed seams must have design                                    ameter of the cylinder. The plane of
                                                                    strength equal to or greater than 1.5                                  the circle must be parallel to the plane

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.65

                                                                    of a circumferential weld and normal                      test ring may include the circumferen-
                                                                    to the long axis of the cylinder.                         tial weld if it is located at a 45 degree
                                                                      (3) Unless a head has adequate thick-                   angle to the ring, ±5 degrees.
                                                                    ness, each opening must be reinforced                        (3) The flattening must be between 60
                                                                    by a securely attached fitting, boss,                     degrees included-angle, wedge shaped
                                                                    pad, collar, or other suitable means.                     knife edges, rounded to a 0.5 inch ra-
                                                                      (4) Material used for welded openings                   dius.
                                                                    and attachments must be of weldable                          (4) Cylinders and test rings may not
                                                                    quality and compatible with the mate-                     crack when flattened so that their
                                                                    rial of the cylinder.                                     outer surfaces are not more than six
                                                                      (f) Pressure tests. (1) Each cylinder                   times wall thickness apart when made
                                                                    must be tested at an internal pressure                    of steel or not more than ten times
                                                                    of at least the test pressure and must                    wall thickness apart when made of alu-
                                                                    be held at that pressure for at least 30                  minum.
                                                                    seconds.                                                     (5) If any cylinder or ring cracks
                                                                      (i) The leakage test must be con-                       when subjected to the specified flat-
                                                                    ducted by submersion under water or                       tening test, the lot of cylinders rep-
                                                                    by some other method that will be                         resented by the test must be rejected
                                                                    equally sensitive.                                        (see paragraph (h) of this section).
                                                                      (ii) If the cylinder leaks, evidences                      (h) Rejected cylinders. Rejected cyl-
                                                                    visible distortion, or any other defect,                  inders must conform to the following
                                                                    while under test, it must be rejected                     requirements:
                                                                    (see paragraph (h) of this section).                         (1) If the cause for rejection of a lot
                                                                      (2) One cylinder taken from the be-                     is determinable, and if by test or in-
                                                                    ginning of each lot, and one from each                    spection defective cylinders are elimi-
                                                                    1,000 or less successively produced                       nated from the lot, the remaining cyl-
                                                                    within the lot thereafter, must be                        inders must be qualified as a new lot
                                                                    hydrostatically tested to destruction.                    under paragraphs (f) and (g) of this sec-
                                                                    The entire lot must be rejected (see                      tion.
                                                                    paragraph (h) of this section) if:                           (2) Repairs to welds are permitted.
                                                                      (i) A failure occurs at a gage pressure                 Following repair, a cylinder must pass
                                                                    less than 2.0 times the test pressure;                    the pressure test specified in paragraph
                                                                      (ii) A failure initiates in a braze or a                (f) of this section.
                                                                    weld or the heat affected zone thereof;                      (3) If a cylinder made from seamless
                                                                      (iii) A failure is other than in the                    steel tubing fails the flattening test de-
                                                                    sidewall of a cylinder longitudinal with                  scribed in paragraph (g) of this section,
                                                                    its long axis; or                                         suitable uniform heat treatment must
                                                                      (iv) In a sphere, a failure occurs in                   be used on each cylinder in the lot. All
                                                                    any opening, reinforcement, or at a                       prescribed tests must be performed
                                                                    point of attachment.                                      subsequent to this heat treatment.
                                                                      (3) A ‘‘lot’’ is defined as the quantity                   (i) Markings. (1) The markings re-
                                                                    of cylinders successively produced per                    quired by this section must be durable
                                                                    production shift (not exceeding 10                        and waterproof. The requirements of
                                                                    hours) having identical size, design,                     § 178.35(h) do not apply to this section.
                                                                    construction, material, heat treat-                          (2) Required markings are as follows:
                                                                    ment, finish, and quality.                                   (i) DOT-39.
                                                                      (g) Flattening test. One cylinder must                     (ii) NRC.
                                                                    be taken from the beginning of produc-                       (iii) The service pressure.
                                                                    tion of each lot (as defined in para-                        (iv) The test pressure.
                                                                    graph (f)(3) of this section) and sub-                       (v) The registration number (M****)
                                                                    jected to a flattening test as follows:                   of the manufacturer.
                                                                      (1) The flattening test must be made                       (vi) The lot number.
                                                                    on a cylinder that has been tested at                        (vii) The date of manufacture if the
                                                                    test pressure.                                            lot number does not establish the date
                                                                      (2) A ring taken from a cylinder may                    of manufacture.
                                                                    be flattened as an alternative to a test                     (viii) With one of the following state-
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                                                                    on a complete cylinder. The test ring                     ments:
                                                                    may not include the heat affected zone                       (A) For cylinders manufactured prior
                                                                    or any weld. However, for a sphere, the                   to October 1, 1996: ‘‘Federal law forbids

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                                                                    § 178.68                                                                                          49 CFR Ch. I (10–1–09 Edition)

                                                                    transportation if refilled-penalty up to                                         TABLE 1—AUTHORIZED MATERIALS—Continued
                                                                    $25,000 fine and 5 years imprisonment
                                                                                                                                                                                                 Chemical analysis—limits in
                                                                    (49 U.S.C. 1809)’’ or ‘‘Federal law for-                                                  Designation                             percent 5154 1
                                                                    bids transportation if refilled-penalty
                                                                    up to $500,000 fine and 5 years imprison-                                    Magnesium ...........................          3.10/3.90.
                                                                                                                                                 Chromium .............................         0.15/0.35.
                                                                    ment (49 U.S.C. 5124).’’                                                     Zinc .......................................   0.20 maximum.
                                                                      (B) For cylinders manufactured on or                                       Titanium ................................      0.20 maximum.
                                                                    after October 1, 1996: ‘‘Federal law for-                                    Others, each .........................         0.05 maximum.
                                                                                                                                                 Others, total ..........................       0.15 maximum.
                                                                    bids transportation if refilled-penalty                                      Aluminum ..............................        remainder.
                                                                    up to $500,000 fine and 5 years imprison-                                      1 Analysis must regularly be made only for the elements
                                                                    ment (49 U.S.C. 5124).’’                                                     specifically mentioned in this table. If, however, the presence
                                                                      (3) The markings required by para-                                         of other elements is indicated in the course of routine anal-
                                                                                                                                                 ysis, further analysis should be made to determine conform-
                                                                    graphs (i)(2)(i) through (i)(2)(v) of this                                   ance with the limits specified for other elements.
                                                                    section must be in numbers and letters
                                                                                                                                                   (c) Identification. Material must be
                                                                    at least 1⁄8 inch high and displayed se-
                                                                                                                                                 identified by any suitable method that
                                                                    quentially. For example:
                                                                                                                                                 will identify the alloy and manufactur-
                                                                    DOT-39 NRC 250/500 M1001.                                                    er’s lot number.
                                                                      (4) No person may mark any cylinder                                          (d) Manufacture. Cylinders must be
                                                                    with the specification identification                                        manufactured using equipment and
                                                                    ‘‘DOT-39’’ unless it was manufactured                                        processes adequate to ensure that each
                                                                    in compliance with the requirements of                                       cylinder produced conforms to the re-
                                                                    this section and its manufacturer has a                                      quirements of this subpart. No defect is
                                                                    registration number (M****) from the                                         permitted that is likely to weaken the
                                                                    Associate Administrator.                                                     finished cylinder appreciably. A rea-
                                                                                                                                                 sonably smooth and uniform surface
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as                                finish is required. All welding must be
                                                                    amended at 65 FR 58631, Sept. 29, 2000; 66 FR                                by the gas shielded arc process.
                                                                    45389, Aug. 28, 2001; 67 FR 51654, Aug. 8, 2002;
                                                                                                                                                   (e) Welding. The attachment to the
                                                                    68 FR 75748, 75749, Dec. 31, 2003]
                                                                                                                                                 tops and bottoms only of cylinders by
                                                                    § 178.68 Specification 4E welded alu-                                        welding of neckrings or flanges,
                                                                         minum cylinders.                                                        footrings, handles, bosses and pads and
                                                                                                                                                 valve protection rings is authorized.
                                                                       (a) Type, size and service pressure. A
                                                                                                                                                 However, such attachments and the
                                                                    DOT 4E cylinder is a welded aluminum
                                                                                                                                                 portion of the cylinder to which it is
                                                                    cylinder with a water capacity (nomi-
                                                                                                                                                 attached must be made of weldable alu-
                                                                    nal) of not over 1,000 pounds and a serv-
                                                                                                                                                 minum alloys.
                                                                    ice pressure of at least 225 to not over
                                                                                                                                                   (f) Wall thickness. The wall thickness
                                                                    500 psig. The cylinder must be con-
                                                                                                                                                 of the cylinder must conform to the
                                                                    structed of not more than two seamless
                                                                                                                                                 following:
                                                                    drawn shells with no more than one
                                                                                                                                                   (1) The minimum wall thickness of
                                                                    circumferential weld. The circumferen-
                                                                                                                                                 the cylinder must be 0.140 inch. In any
                                                                    tial weld may not be closer to the point
                                                                                                                                                 case, the minimum wall thickness
                                                                    of tangency of the cylindrical portion
                                                                                                                                                 must be such that calculated wall
                                                                    with the shoulder than 20 times the
                                                                                                                                                 stress at twice service pressure may
                                                                    cylinder wall thickness. Cylinders or
                                                                                                                                                 not exceed the lesser value of either of
                                                                    shells closed in by spinning process and
                                                                                                                                                 the following:
                                                                    cylinders with longitudinal seams are
                                                                                                                                                   (i) 20,000 psi.
                                                                    not authorized.
                                                                                                                                                   (ii) One-half of the minimum tensile
                                                                       (b) Authorized material. The cylinder
                                                                                                                                                 strength of the material as required in
                                                                    must be constructed of aluminum of
                                                                                                                                                 paragraph (j) of this section.
                                                                    uniform quality. The following chem-
                                                                                                                                                   (2) Calculation must be made by the
                                                                    ical analyses are authorized:
                                                                                                                                                 following formula:
                                                                                TABLE 1—AUTHORIZED MATERIALS                                     S = [P(1.3D2 + 0.4d2)] / (D2 ¥ d2)

                                                                                Designation                      Chemical analysis—limits in     Where:
                                                                                                                      percent 5154 1
                                                                                                                                                 S = wall stress in psi;
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                                                                    Iron plus silicon ....................      0.45 maximum.                    P = minimum test pressure prescribed for
                                                                    Copper ..................................   0.10 maximum.                      water jacket test;
                                                                    Manganese ...........................       0.10 maximum.                    D = outside diameter in inches;

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.68
                                                                    d = inside diameter in inches.                               (i) At least one cylinder selected at
                                                                      (3) Minimum thickness of heads and                      random out of each lot of 200 or less
                                                                    bottoms may not be less than the min-                     must be tested in accordance with
                                                                    imum required thickness of the side                       paragraphs (h)(1), (h)(2), and (h)(3) of
                                                                    wall.                                                     this section.
                                                                      (g) Opening in cylinder. Openings in                       (ii) All cylinders not tested as pro-
                                                                    cylinders must conform to the fol-                        vided in paragraph (h)(4)(i) of this sec-
                                                                    lowing:                                                   tion must be examined under pressure
                                                                      (1) All openings must be in the heads                   of at least 2 times service pressure and
                                                                    or bases.                                                 show no defect.
                                                                      (2) Each opening in cylinders, except                      (5) One finished cylinder selected at
                                                                    those for safety devices, must be pro-                    random out of each lot of 1,000 or less
                                                                    vided with a fitting, boss, or pad, se-                   must be hydrostatically tested to 4
                                                                    curely attached to cylinder by welding                    times the service pressure without
                                                                    by inert gas shielded arc process or by                   bursting. Inability to meet this re-
                                                                    threads. If threads are used, they must                   quirement must result in rejection of
                                                                    comply with the following:
                                                                                                                              the lot.
                                                                      (i) Threads must be clean-cut, even,
                                                                    without checks and cut to gauge.                             (i) Flattening test. After hydrostatic
                                                                      (ii) Taper threads to be of length not                  testing, a flattening test is required on
                                                                    less than as specified for American                       one section of a cylinder, taken at ran-
                                                                    Standard taper pipe threads.                              dom out of each lot of 200 or less as fol-
                                                                      (iii) Straight threads, having at least                 lows:
                                                                    4 engaged threads, to have tight fit and                     (1) If the weld is not at midlength of
                                                                    calculated shear strength at least 10                     the cylinder, the test section must be
                                                                    times the test pressure of the cylinder;                  no less in width than 30 times the cyl-
                                                                    gaskets required, adequate to prevent                     inder wall thickness. The weld must be
                                                                    leakage.                                                  in the center of the section. Weld rein-
                                                                      (3) Closure of a fitting, boss, or pad                  forcement must be removed by machin-
                                                                    must be adequate to prevent leakage.                      ing or grinding so that the weld is flush
                                                                      (h) Hydrostatic test. Each cylinder                     with the exterior of the parent metal.
                                                                    must successfully withstand a hydro-                      There must be no evidence of cracking
                                                                    static test, as follows:                                  in the sample when it is flattened be-
                                                                      (1) The test must be by water jacket,                   tween flat plates to no more than 6
                                                                    or other suitable method, operated so                     times the wall thickness.
                                                                    as to obtain accurate data. The pres-                        (2) Guided bend test. A bend test speci-
                                                                    sure gauge must permit reading to an                      men must be cut from the cylinder
                                                                    accuracy of 1 percent. The expansion                      used for the physical test specified in
                                                                    gauge must permit a reading of the
                                                                                                                              paragraph (j) of this section. Specimen
                                                                    total expansion to an accuracy either
                                                                                                                              must be taken across the seam, must
                                                                    of 1 percent or 0.1 cubic centimeter.
                                                                                                                              be a minimum of 11⁄2 inches wide, edges
                                                                      (2) Pressure of 2 times service pres-
                                                                                                                              must be parallel and rounded with a
                                                                    sure must be maintained for at least 30
                                                                                                                              file, and back-up strip, if used, must be
                                                                    seconds and sufficiently longer to in-
                                                                    sure complete expansion. Any internal                     removed by machining. The specimen
                                                                    pressure applied previous to the official                 shall be tested as follows:
                                                                    test may not exceed 90 percent of the                        (i) The specimen must be bent to re-
                                                                    test pressure. If, due to failure of the                  fusal in the guided bend test jig as il-
                                                                    test apparatus, the test pressure can-                    lustrated in paragraph 6.10 of CGA C–3
                                                                    not be maintained, the test may be re-                    (IBR, see § 171.7 of this subchapter). The
                                                                    peated at a pressure increased by 10                      root of the weld (inside surface of the
                                                                    percent over the pressure otherwise                       cylinder) must be located away from
                                                                    specified.                                                the ram of the jig. The specimen must
                                                                      (3) Permanent volumetric expansion                      not show a crack or other open defect
                                                                    may not exceed 12 percent of total vol-                   exceeding 1⁄8 inch in any direction upon
                                                                    umetric expansion at test pressure.                       completion of the test. Should this
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                                                                      (4) Cylinders having a calculated wall                  specimen fail to meet the require-
                                                                    stress of 18,000 psi or less at test pres-                ments, specimens may be taken from
                                                                    sure may be tested as follows:                            each of 2 additional cylinders from the

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                                                                    § 178.68                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    same lot and tested. If either of the lat-                  (i) The yield strength must be deter-
                                                                    ter specimens fails to meet require-                      mined by the ‘‘offset’’ method as pre-
                                                                    ments, the entire lot represented must                    scribed in ASTM E 8 (IBR, see § 171.7 of
                                                                    be rejected.                                              this subchapter).
                                                                      (ii) Alternatively, the specimen may                      (ii) Cross-head speed of the testing
                                                                    be tested in a guided bend test jig as il-                machine may not exceed 1⁄8 inch per
                                                                    lustrated in Figure 12.1 of The Alu-                      minute during yield strength deter-
                                                                    minum Association’s 2002 publication,                     mination.
                                                                    ‘‘Welding Aluminum: Theory and Prac-                        (k) Acceptable results for physical tests.
                                                                    tice.’’ The root of the weld (inside sur-                 An acceptable result of the physical
                                                                    face of the cylinder) must be located                     test requires an elongation to at least
                                                                    away from the mandrel of the jig. No                      7 percent and yield strength not over 80
                                                                    specimen must show a crack or other                       percent of tensile strength.
                                                                    open defect exceeding 1⁄8 inch in any di-                   (l) Weld tests. Welds of the cylinder
                                                                    rection upon completion of the test.                      are required to successfully pass the
                                                                    Should this specimen fail to meet the                     following tests:
                                                                    requirements, specimens may be taken                        (1) Reduced section tensile test. A speci-
                                                                    from each of 2 additional cylinders                       men must be cut from the cylinder
                                                                    from the same lot and tested. If either                   used for the physical tests specified in
                                                                    of the latter specimens fails to meet                     paragraph (j) of this section. The speci-
                                                                    requirements, the entire lot rep-                         men must be taken from across the
                                                                    resented must be rejected.                                seam, edges must be parallel for a dis-
                                                                      (j) Physical test. A physical test must                 tance of approximately 2 inches on ei-
                                                                    be conducted to determine yield                           ther side of the weld. The specimen
                                                                    strength, tensile strength, elongation,                   must be fractured in tension. The ap-
                                                                    and reduction of area of material as                      parent breaking stress calculated on
                                                                    follows:                                                  the minimum wall thickness must be
                                                                      (1) The test is required on 2 speci-                    at least equal to 2 times the stress cal-
                                                                    mens cut from one cylinder or part                        culated under paragraph (f)(2) of this
                                                                    thereof taken at random out of each                       section, and in addition must have an
                                                                    lot of 200 or less.                                       actual breaking stress of at least 30,000
                                                                      (2) Specimens must conform to the                       psi. Should this specimen fail to meet
                                                                    following:                                                the requirements, specimens may be
                                                                      (i) A gauge length of 8 inches with a                   taken from 2 additional cylinders from
                                                                    width not over 11⁄2 inches, a gauge                       the same lot and tested. If either of the
                                                                    length of 2 inches with a width not                       latter specimens fails to meet require-
                                                                    over 11⁄2 inches.                                         ments, the entire lot represented must
                                                                      (ii) The specimen, exclusive of grip                    be rejected.
                                                                    ends, may not be flattened. Grip ends                       (2) Guided bend test. A bend test speci-
                                                                    may be flattened to within 1 inch of                      men must be cut from the cylinder
                                                                    each end of the reduced section.                          used for the physical tests specified in
                                                                      (iii) When size of cylinder does not                    paragraph (j) of this section. Specimen
                                                                    permit securing straight specimens,                       must be taken across the seam, must
                                                                    the specimens may be taken in any lo-                     be 11⁄2 inches wide, edges must be par-
                                                                    cation or direction and may be                            allel and rounded with a file, and back-
                                                                    straightened or flattened cold, by pres-                  up strip, if used, must be removed by
                                                                    sure only, not by blows; when speci-                      machining. The specimen must be bent
                                                                    mens are so taken and prepared, the in-                   to refusal in the guided bend test jig il-
                                                                    spector’s report must show in connec-                     lustrated in paragraph 6.10 of CGA
                                                                    tion with record of physical test de-                     Pamphlet C–3 (IBR, see § 171.7 of this
                                                                    tailed information in regard to such                      subchapter). The root of the weld (in-
                                                                    specimens.                                                side surface of the cylinder) must be lo-
                                                                      (iv) Heating of a specimen for any                      cated away from the ram of the jig. No
                                                                    purpose is not authorized.                                specimen must show a crack or other
                                                                      (3) The yield strength in tension                       open defect exceeding 1⁄8 inch in any di-
                                                                    must be the stress corresponding to a                     rection upon completion of the test.
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                                                                    permanent strain of 0.2 percent of the                    Should this specimen fail to meet the
                                                                    gauge length. The following conditions                    requirements, specimens may be taken
                                                                    apply:                                                    from each of 2 additional cylinders

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.69

                                                                    from the same lot and tested. If either                   quirements in § 178.70. The quality sys-
                                                                    of the latter specimens fail to meet re-                  tem records must be in English and
                                                                    quirements, the entire lot represented                    must include detailed descriptions of
                                                                    must be rejected.                                         the following:
                                                                      (m) Rejected cylinders. Repair of weld-                   (i) The organizational structure and
                                                                    ed seams is authorized. Acceptable cyl-                   responsibilities of personnel with re-
                                                                    inders must pass all prescribed tests.                    gard to design and product quality;
                                                                      (n) Inspector’s report. In addition to                    (ii) The design control and design
                                                                    the information required by § 178.35, the                 verification techniques, processes, and
                                                                    record of chemical analyses must also                     procedures used when designing the
                                                                    include applicable information on iron,                   pressure receptacles;
                                                                    titanium, zinc, and magnesium used in                       (iii) The relevant procedures for pres-
                                                                    the construction of the cylinder.                         sure receptacle manufacturing, quality
                                                                    [Amdt. 178–114, 61 FR 25942, May 23, 1996, as             control, quality assurance, and process
                                                                    amended at 62 FR 51561, Oct. 1, 1997; 66 FR               operation instructions;
                                                                    45386, Aug. 28, 2001; 67 FR 51654, Aug. 8, 2002;            (iv) Inspection and testing meth-
                                                                    68 FR 75748, Dec. 31, 2003; 69 FR 54046, Sept.            odologies, measuring and testing equip-
                                                                    7, 2004; 74 FR 16143, Apr. 9, 2009]                       ment, and calibration data;
                                                                    § 178.69 Responsibilities and require-                      (v) The process for meeting customer
                                                                        ments for manufacturers of UN                         requirements;
                                                                        pressure receptacles.                                   (vi) The process for document control
                                                                                                                              and document revision;
                                                                      (a) Each manufacturer of a UN pres-
                                                                    sure receptacle marked with ‘‘USA’’ as                      (vii) The system for controlling non-
                                                                    a country of approval must comply                         conforming material and records, in-
                                                                    with the requirements in this section.                    cluding procedures for identification,
                                                                    The manufacturer must maintain a                          segregation, and disposition;
                                                                    quality system, obtain an approval for                      (viii) Production, processing and fab-
                                                                    each initial pressure receptacle design                   rication, including purchased compo-
                                                                    type, and ensure that all production of                   nents, in-process and final materials;
                                                                    UN pressure receptacles meets the ap-                     and
                                                                    plicable requirements.                                      (ix) Training programs for relevant
                                                                      (1) Quality system. The manufacturer                    personnel.
                                                                    of a UN pressure receptacle must have                       (3) Maintenance of quality system. The
                                                                    its quality system approved by the As-                    manufacturer must maintain the qual-
                                                                    sociate Administrator. The quality sys-                   ity system as approved by the Asso-
                                                                    tem will initially be assessed through                    ciate Administrator. The manufacturer
                                                                    an audit by the Associate Adminis-                        shall notify the Associate Adminis-
                                                                    trator or his or her representative to                    trator of any intended changes to the
                                                                    determine whether it meets the re-                        approved quality system prior to mak-
                                                                    quirements of this section. The Asso-                     ing the change. The Associate Adminis-
                                                                    ciate Administrator will notify the                       trator will evaluate the proposed
                                                                    manufacturer in writing of the results                    change to determine whether the
                                                                    of the audit. The notification will con-                  amended quality system will satisfy
                                                                    tain the conclusions of the audit and                     the requirements. The Associate Ad-
                                                                    any corrective action required. The As-                   ministrator will notify the manufac-
                                                                    sociate Administrator may perform                         turer of the findings.
                                                                    periodic audits to ensure that the man-                     (b) Design type approvals. The manu-
                                                                    ufacturer operates in accordance with                     facturer must have each pressure re-
                                                                    the quality system. Reports of periodic                   ceptacle design type reviewed by an IIA
                                                                    audits will be provided to the manufac-                   and approved by the Associate Admin-
                                                                    turer. The manufacturer must bear the                     istrator in accordance with § 178.70. A
                                                                    cost of audits.                                           cylinder is considered to be of a new
                                                                      (2) Quality system documentation. The                   design, compared with an existing ap-
                                                                    manufacturer must be able to dem-                         proved design, as stated in the applica-
                                                                    onstrate a documented quality system.                     ble ISO design, construction and test-
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                                                                    Management must review the adequacy                       ing standard.
                                                                    of the quality system to assure that it                     (c) Production inspection and certifi-
                                                                    is effective and conforms to the re-                      cation. The manufacturer must ensure

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                                                                    § 178.70                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    that each UN pressure receptacle is in-                   and the IIA certifying the design type,
                                                                    spected and certified in accordance                       the test results, chemical analyses, lot
                                                                    with § 178.71.                                            identification, and all other supporting
                                                                    [71 FR 33885, June 12, 2006]
                                                                                                                              data specified in the applicable ISO de-
                                                                                                                              sign, construction and testing stand-
                                                                    § 178.70 Approval of UN pressure re-                      ard. The IIA must provide the certifi-
                                                                         ceptacles.                                           cate and documentation to the manu-
                                                                       (a) Initial design-type approval. The                  facturer.
                                                                    manufacturer of a UN pressure recep-                         (c) Application for initial design type
                                                                    tacle must obtain an initial design                       approval. If the pre-audit is found satis-
                                                                    type approval from the Associate Ad-                      factory by the IIA, the manufacturer
                                                                    ministrator. The initial design type ap-                  will submit the letter of recommenda-
                                                                    proval must be of the pressure recep-                     tion from the IIA and an application
                                                                    tacle design as it is intended to be pro-                 for design type approval to the Asso-
                                                                    duced. The manufacturer must arrange                      ciate Administrator. An application for
                                                                    for an IIA, approved by the Associate                     initial design type approval must be
                                                                    Administrator in accordance with sub-                     submitted for each manufacturing fa-
                                                                    part I of part 107 of this chapter, to                    cility. The application must be in
                                                                    perform a pre-audit of its pressure re-                   English and, at a minimum, contain
                                                                    ceptacle manufacturing operation prior                    the following information:
                                                                    to having an audit conducted by the                          (1) The name and address of the man-
                                                                    Associate Administrator or his des-                       ufacturing facility. If the application is
                                                                    ignee.                                                    submitted by an authorized representa-
                                                                       (b) IIA pre-audit. The manufacturer                    tive on behalf of the manufacturer, the
                                                                    must submit an application for initial                    application must include the represent-
                                                                    design type approval to the IIA for re-                   ative’s name and address.
                                                                    view. The IIA will examine the manu-                         (2) The name and title of the indi-
                                                                    facturer’s application for initial design                 vidual responsible for the manufactur-
                                                                    type approval for completeness. An in-                    er’s quality system, as required by
                                                                    complete application will be returned                     § 178.69.
                                                                    to the manufacturer with an expla-                           (3) The designation of the pressure
                                                                    nation. If an application is complete,                    receptacle and the relevant pressure re-
                                                                    the IIA will review all technical docu-                   ceptacle standard.
                                                                    mentation, including drawings and cal-                       (4) Details of any refusal of approval
                                                                    culations, to verify that the design                      of a similar application by a designated
                                                                    meets all requirements of the applica-                    approval agency of another country.
                                                                    ble UN pressure receptacle standard                          (5) The name and address of the pro-
                                                                    and specification requirements. If the                    duction IIA that will perform the func-
                                                                    technical documentation shows that                        tions prescribed in paragraph (e) of this
                                                                    the pressure receptacle prototype de-                     section. The IIA must be approved in
                                                                    sign conforms to the applicable stand-                    writing by the Associate Administrator
                                                                    ards and requirements in § 178.70, the                    in accordance with subpart I of part 107
                                                                    manufacturer will fabricate a proto-                      of this chapter.
                                                                    type lot of pressure receptacles in con-                     (6) Documentation on the manufac-
                                                                    formance with the technical docu-                         turing facility as specified in § 178.69.
                                                                    mentation representative of the design.                      (7) Design specifications and manu-
                                                                    The IIA will verify that the prototype                    facturing drawings, showing compo-
                                                                    lot conforms to the applicable require-                   nents and subassemblies if relevant, de-
                                                                    ments by selecting pressure receptacles                   sign calculations, and material speci-
                                                                    and witnessing their testing. After pro-                  fications necessary to verify compli-
                                                                    totype testing has been satisfactorily                    ance with the applicable pressure re-
                                                                    completed, showing the pressure recep-                    ceptacle design standard.
                                                                    tacles fully conform to all applicable                       (8) Manufacturing procedures and
                                                                    specification requirements, the certi-                    any applicable standards that describe
                                                                    fying IIA must prepare a letter of rec-                   in detail the manufacturing processes
                                                                    ommendation and a design type ap-                         and control.
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                                                                    proval certificate. The design type ap-                      (9) Design type approval test reports
                                                                    proval certificate must contain the                       detailing the results of examinations
                                                                    name and address of the manufacturer                      and tests conducted in accordance with

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.70

                                                                    the relevant pressure receptacle stand-                     (2) During the audit, the manufac-
                                                                    ard, to include any additional data,                      turer will be required to produce pres-
                                                                    such as suitability for underwater ap-                    sure receptacles to the technical stand-
                                                                    plications or compatibility with hydro-                   ards for which approval is sought.
                                                                    gen embrittlement gases.                                    (3) The production IIA must witness
                                                                       (d) Modification of approved pressure                  the      required     inspections     and
                                                                    receptacle design type. Modification of                   verifications on the pressure recep-
                                                                    an approved UN pressure receptacle de-                    tacles during the production run. The
                                                                    sign type is not authorized without the                   IIA selected by the manufacturer for
                                                                    approval of the Associate Adminis-                        production inspection and testing may
                                                                    trator. A manufacturer seeking modi-                      be different from the IIA who per-
                                                                    fication of an approved UN pressure re-                   formed the design type approval
                                                                    ceptacle design type may be required                      verifications.
                                                                    to submit design qualification test                         (4) If the procedures and controls are
                                                                    data to the Associate Administrator                       deemed acceptable, test sample pres-
                                                                    before production. An audit may be re-                    sure receptacles will be selected at ran-
                                                                    quired as part of the process to modify                   dom from the production lot and sent
                                                                    an approval.                                              to a laboratory designated by the Asso-
                                                                       (e) Responsibilities of the production                 ciate Administrator for verification
                                                                    IIA. The production IIA is responsible                    testing.
                                                                    for ensuring that each pressure recep-                      (5) If the pressure receptacle test
                                                                    tacle conforms to the design type ap-                     samples are found to conform to all the
                                                                    proval. The production IIA must per-                      applicable requirements, the Associate
                                                                    form the following functions:                             Administrator will issue approvals to
                                                                       (1) Witness all inspections and tests                  the manufacturer and the production
                                                                    specified in the UN pressure receptacle                   IIA to authorize the manufacture of
                                                                    standard to ensure compliance with the                    the pressure receptacles. The approved
                                                                    standard and that the procedures                          design type approval certificate will be
                                                                    adopted by the manufacturer meet the                      returned to the manufacturer.
                                                                    requirements of the standard;                               (6) Upon the receipt of the approved
                                                                       (2) Verify that the production inspec-                 design type approval certificate from
                                                                    tions were performed in accordance                        the Associate Administrator, the pres-
                                                                    with this section;                                        sure receptacle manufacturer must
                                                                       (3) Select UN pressure receptacles                     sign the certificate.
                                                                    from a prototype production lot and                         (g) Recordkeeping. The production IIA
                                                                    witness testing as required for the de-                   and the manufacturer must retain a
                                                                    sign type approval;                                       copy of the design type approval cer-
                                                                       (4) Ensure that the various design                     tificate and certificate of compliance
                                                                    type approval examinations and tests                      records for at least 20 years.
                                                                    are performed accurately;                                   (h) Denial of design type application. If
                                                                       (5) Verify that each pressure recep-                   the design type application is denied,
                                                                    tacle is marked in accordance with the                    the Associate Administrator will no-
                                                                    applicable requirements in § 178.72; and                  tify the applicant in writing and pro-
                                                                       (6) Furnish complete test reports to                   vide the reason for the denial. The
                                                                    the manufacturer and upon request to                      manufacturer may request that the As-
                                                                    the purchaser. The test reports and                       sociate Administrator reconsider the
                                                                    certificate of compliance must be re-                     decision. The application request
                                                                    tained by the IIA for at least 20 years                   must—
                                                                    from the original test date of the pres-                    (1) Be written in English and filed
                                                                    sure receptacles.                                         within 60 days of receipt of the deci-
                                                                       (f) Production inspection audit and cer-               sion;
                                                                    tification. (1) If the application, design                  (2) State in detail any alleged errors
                                                                    drawing and quality control documents                     of fact and law; and
                                                                    are found satisfactory, PHMSA will                          (3) Enclose any additional informa-
                                                                    schedule an on-site audit of the pres-                    tion needed to support the request to
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                                                                    sure receptacle manufacturer’s quality                    reconsider.
                                                                    system, manufacturing processes, in-                        (i) Appeal. (1) A manufacturer whose
                                                                    spections, and test procedures.                           reconsideration request is denied may

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                                                                    § 178.71                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    appeal to the PHMSA Administrator.                        this section. Requirements for ap-
                                                                    The appeal must—                                          proval, qualification, maintenance, and
                                                                      (i) Be written in English and filed                     testing are contained in § 178.70, and
                                                                    within 60 days of receipt of the Asso-                    subpart C of part 180 of this subchapter.
                                                                    ciate Administrator’s decision on re-                       (b) Definitions. The following defini-
                                                                    consideration;                                            tions apply for the purposes of design
                                                                      (ii) State in detail any alleged errors                 and construction of UN pressure recep-
                                                                    of fact and law;                                          tacles under this subpart:
                                                                      (iii) Enclose any additional informa-                     Alternative arrangement means an ap-
                                                                    tion needed to support the appeal; and                    proval granted by the Associate Ad-
                                                                      (iv) State in detail the modification                   ministrator for a MEGC that has been
                                                                    of the final decision sought.                             designed, constructed or tested to the
                                                                      (2) The PHMSA Administrator will                        technical requirements or testing
                                                                    grant or deny the relief and inform the                   methods other than those specified for
                                                                    appellant in writing of the decision.                     UN pressure receptacles in part 178 or
                                                                    PHMSA Administrator’s decision is the                     part 180 of this subchapter.
                                                                    final administrative action.                                Bundle of cylinders. See § 171.8 of this
                                                                      (j) Termination of a design type ap-                    subchapter.
                                                                    proval certificate. (1) The Associate Ad-                   Design type means a pressure recep-
                                                                    ministrator may terminate an approval                     tacle design as specified by a particular
                                                                    certificate issue under this section if it                pressure receptacle standard.
                                                                    is determined that, because of a change                     Design type approval means an overall
                                                                    in circumstances, the approval no                         approval of the manufacturer’s quality
                                                                    longer is needed or no longer would be                    system and design type of each pres-
                                                                    granted if applied for; information                       sure receptacle to be produced within
                                                                    upon which the approval was based is                      the manufacturer’s facility.
                                                                    fraudulent or substantially erroneous;                      UN tube. See § 171.8 of this sub-
                                                                    or termination of the approval is nec-                    chapter.
                                                                    essary to adequately protect against                        (c) General design and construction.
                                                                    risks to life and property.                               UN pressure receptacles and their clo-
                                                                      (2) Before an approval is terminated,                   sures must be designed, manufactured,
                                                                    the Associate Administrator will pro-                     tested and equipped in accordance with
                                                                    vide the manufacturer and the ap-                         the requirements contained in this sec-
                                                                    proval agency—                                            tion.
                                                                      (i) Written notice of the facts or con-                   (1) Following the final heat treat-
                                                                    duct believed to warrant the with-                        ment, all cylinders, except those se-
                                                                    drawal;                                                   lected for batch testing must be sub-
                                                                      (ii) Opportunity to submit oral and                     jected to a hydraulic volumetric expan-
                                                                    written evidence, and                                     sion test.
                                                                      (iii) Opportunity to demonstrate or                       (2) The standard requirements appli-
                                                                    achieve compliance with the applica-                      cable to UN pressure receptacles may
                                                                    tion requirement.                                         be varied only if approved in writing by
                                                                      (3) If the Associate Administrator de-                  the Associate Administrator.
                                                                    termines that a certificate of approval                     (3) The test pressure of UN cylinders,
                                                                    must be withdrawn to preclude a sig-                      tubes, and bundles of cylinders must
                                                                    nificant and imminent adverse affect                      conform to the requirements in part
                                                                    on public safety, the procedures in                       178 of this subchapter.
                                                                    paragraph (j)(2)(ii) and (iii) of this sec-                 (d) Service equipment. (1) Except for
                                                                    tion need not be provided prior to with-                  pressure relief devices, UN pressure re-
                                                                    drawal of the approval, but shall be                      ceptacle equipment, including valves,
                                                                    provided as soon as practicable there-                    piping, fittings, and other equipment
                                                                    after.                                                    subjected to pressure must be designed
                                                                    [71 FR 33886, June 12, 2006, as amended at 71             and constructed to withstand at least
                                                                    FR 54397, Sept. 14, 2006]                                 1.5 times the test pressure of the pres-
                                                                                                                              sure receptacle.
                                                                    § 178.71 Specifications for UN pressure                     (2) Service equipment must be config-
                                                                         receptacles.
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                                                                                                                              ured or designed to prevent damage
                                                                       (a) General. Each UN pressure recep-                   that could result in the release of the
                                                                    tacle must meet the requirements of                       pressure receptacle contents during

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.71

                                                                    normal conditions of handling and                         bundle to be lifted by two rings. Where
                                                                    transport. Manifold piping leading to                     two or four lifting rings are used, dia-
                                                                    shut-off valves must be sufficiently                      metrically opposite lifting rings must
                                                                    flexible to protect the valves and the                    be aligned with each other to allow for
                                                                    piping from shearing or releasing the                     correct lifting using shackle pins. If
                                                                    pressure receptacle contents. The fill-                   the bundle is filled with forklift pock-
                                                                    ing and discharge valves and any pro-                     ets, it must contain two forklift pock-
                                                                    tective caps must be secured against                      ets on each side from which it is to be
                                                                    unintended opening. The valves must                       lifted. The forklift pockets must be po-
                                                                    conform to ISO 10297 (IBR, see § 171.7 of                 sitioned symmetrically consistent with
                                                                    this subchapter) and be protected as                      the bundle center of gravity.
                                                                    specified in § 173.301b(f) of this sub-                      (3) The frame structural members
                                                                    chapter.                                                  must be designed for a vertical load of
                                                                       (3) UN pressure receptacles that can-                  2 times the maximum gross weight of
                                                                    not be handled manually or rolled,                        the bundle. Design stress levels may
                                                                    must be equipped with devices (e.g.                       not exceed 0.9 times the yield strength
                                                                    skids, rings, straps) ensuring that they                  of the material.
                                                                    can be safely handled by mechanical                          (4) The frame may not contain any
                                                                    means and so arranged as not to impair                    protrusions from the exterior frame
                                                                    the strength of, nor cause undue                          structure that could cause a hazardous
                                                                    stresses, in the pressure receptacle.                     condition.
                                                                       (4) Pressure receptacles filled by vol-
                                                                                                                                 (5) The frame design must prevent
                                                                    ume must be equipped with a level in-
                                                                                                                              collection of water or other debris that
                                                                    dicator.
                                                                                                                              would increase the tare weight of bun-
                                                                       (e) Bundles of cylinders. UN pressure
                                                                                                                              dles filled by weight.
                                                                    receptacles assembled in bundles must
                                                                                                                                 (6) The floor of the bundle frame
                                                                    be structurally supported and held to-
                                                                                                                              must not buckle during normal oper-
                                                                    gether as a unit and secured in a man-
                                                                                                                              ating conditions and must allow for the
                                                                    ner that prevents movement in rela-
                                                                                                                              drainage of water and debris from
                                                                    tion to the structural assembly and
                                                                                                                              around the base of the cylinders.
                                                                    movement that would result in the
                                                                    concentration      of   harmful      local                   (7) If the frame design includes mov-
                                                                    stresses. The frame design must ensure                    able doors or covers, they must be ca-
                                                                    stability under normal operating con-                     pable of being secured with latches or
                                                                    ditions.                                                  other means that will not become dis-
                                                                       (1) The frame must securely retain                     lodged by operational impact loads.
                                                                    all the components of the bundle and                      Valves that need to be operated in nor-
                                                                    must protect them from damage during                      mal service or in an emergency must
                                                                    conditions normally incident to trans-                    be accessible.
                                                                    portation. The method of cylinder re-                        (f) [Reserved]
                                                                    straint must prevent any vertical or                         (g) Design and construction require-
                                                                    horizontal movement or rotation of the                    ments for UN refillable seamless steel cyl-
                                                                    cylinder that could cause undue strain                    inders. In addition to the general re-
                                                                    on the manifold. The total assembly                       quirements of this section, UN refill-
                                                                    must be able to withstand rough han-                      able seamless steel cylinders must con-
                                                                    dling, including being dropped or over-                   form to the following ISO standards, as
                                                                    turned.                                                   applicable:
                                                                       (2) The frame must include features                       (1) ISO 9809–1: Gas cylinders—Refill-
                                                                    designed for the handling and transpor-                   able seamless steel gas cylinders—De-
                                                                    tation of the bundle. The lifting rings                   sign, construction and testing—Part 1:
                                                                    must be designed to withstand a design                    Quenched and tempered steel cylinders
                                                                    load of 2 times the maximum gross                         with tensile strength less than 1 100
                                                                    weight. Bundles with more than one                        MPa. (IBR, see § 171.7 of this sub-
                                                                    lifting ring must be designed such that                   chapter).
                                                                    a minimum sling angle of 45 degrees to                       (2) ISO 9809–2: Gas cylinders—Refill-
                                                                    the horizontal can be achieved during                     able seamless steel gas cylinders—De-
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                                                                    lifting using the lifting rings. If four                  sign, construction and testing—Part 2:
                                                                    lifting rings are used, their design                      Quenched and tempered steel cylinders
                                                                    must be strong enough to allow the                        with tensile strength greater than or

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                                                                    § 178.71                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    equal to 1 100 MPa. (IBR, see § 171.7 of                  plugs. (IBR, see § 171.7 of this sub-
                                                                    this subchapter).                                         chapter).
                                                                       (3) ISO 9809–3: Gas cylinders—Refill-                     (l) Design and construction require-
                                                                    able seamless steel gas cylinders—De-                     ments for UN composite cylinders. (1) In
                                                                    sign, construction and testing—Part 3:                    addition to the general requirements of
                                                                    Normalized steel cylinders. (IBR, see                     this section, UN composite cylinders
                                                                    § 171.7 of this subchapter).                              must be designed for unlimited service
                                                                       (h) Design and construction require-                   life and conform to the following ISO
                                                                    ments for UN refillable seamless aluminum                 standards, as applicable:
                                                                    alloy cylinders. In addition to the gen-                     (i) ISO 11119–1: Gas cylinders of com-
                                                                    eral requirements of this section, UN                     posite construction—Specification and
                                                                    refillable seamless aluminum cylinders                    test methods—Part 1: Hoop-wrapped
                                                                    must conform to ISO 7866: Gas cyl-                        composite gas cylinders. (IBR, see
                                                                    inders—Refillable seamless aluminum                       § 171.7 of this subchapter).
                                                                    alloy gas cylinders—Design, construc-                        (ii) ISO 11119–2: Gas cylinders of com-
                                                                    tion and testing. (IBR, see § 171.7 of this               posite construction—Specification and
                                                                    subchapter). The use of Aluminum                          test methods—Part 2: Fully-wrapped
                                                                    alloy 6351-T6 or equivalent is prohib-                    fibre reinforced composite gas cyl-
                                                                    ited.                                                     inders with load-sharing metal liners.
                                                                       (i) Design and construction require-                   (IBR, see § 171.7 of this subchapter).
                                                                    ments for UN non-refillable metal cyl-                       (iii) ISO 11119–3: Gas cylinders of
                                                                    inders. In addition to the general re-                    composite construction—Specification
                                                                    quirements of this section, UN non-re-                    and test methods—Part 3: Fully
                                                                    fillable metal cylinders must conform                     wrapped fibre reinforced composite gas
                                                                    to ISO 11118: Gas cylinders—Non-refill-                   cylinders with non-load sharing metal-
                                                                    able metallic gas cylinders—Specifica-                    lic or non-metallic liners. (IBR, see
                                                                    tion and test methods. (IBR, see § 171.7                  § 171.7 of this subchapter).
                                                                    of this subchapter.)                                         (2) ISO 11119–2 and ISO 11119–3 gas
                                                                       (j) Design and construction require-                   cylinders of composite construction
                                                                    ments for UN refillable seamless steel                    manufactured in accordance with the
                                                                    tubes. In addition to the general re-                     requirements for underwater use must
                                                                    quirements of this section, UN refill-                    bear the ‘‘UW’’ mark.
                                                                    able seamless steel tubes must conform                       (m) Material compatibility. In addition
                                                                    to ISO 11120: Gas cylinders—Refillable                    to the material requirements specified
                                                                    seamless steel tubes of water capacity                    in the UN pressure receptacle design
                                                                    between 150 L and 3000 L—Design, con-                     and construction ISO standards, and
                                                                    struction and testing. (IBR, see § 171.7                  any restrictions specified in part 173
                                                                    of this subchapter).                                      for the gases to be transported, the re-
                                                                       (k) Design and construction require-                   quirements of the following standards
                                                                    ments for UN acetylene cylinders. In ad-                  must be applied with respect to mate-
                                                                    dition to the general requirements of                     rial compatibility:
                                                                    this section, UN acetylene cylinders                         (1) ISO 11114–1: Transportable gas cyl-
                                                                    must conform to the following ISO                         inders—Compatibility of cylinder and
                                                                    standards, as applicable:                                 valve materials with gas contents—
                                                                       (1) For the cylinder shell:                            Part 1: Metallic materials. (IBR, see
                                                                       (i) ISO 9809–1: Gas cylinders—Refill-                  § 171.7 of this subchapter).
                                                                    able seamless steel gas cylinders—De-                        (2) ISO 11114–2: Transportable gas cyl-
                                                                    sign, construction and testing—Part 1:                    inders—Compatibility of cylinder and
                                                                    Quenched and tempered steel cylinders                     valve materials with gas contents—
                                                                    with tensile strength less than 1 100                     Part 2: Non-metallic materials. (IBR,
                                                                    MPa.                                                      see § 171.7 of this subchapter).
                                                                       (ii) ISO 9809–3: Gas cylinders—Refill-                    (n) Protection of closures. Closures and
                                                                    able seamless steel gas cylinders—De-                     their protection must conform to the
                                                                    sign, construction and testing—Part 3:                    requirements in § 173.301(f) of this sub-
                                                                    Normalized steel cylinders.                               chapter.
                                                                       (2) The porous mass in an acetylene                       (o) Marking of UN refillable pressure re-
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                                                                    cylinder must conform to ISO 3807–2:                      ceptacles. UN refillable pressure recep-
                                                                    Cylinders for acetylene—Basic require-                    tacles must be marked clearly and leg-
                                                                    ments—Part 2: Cylinders with fusible                      ibly. The required markings must be

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.71

                                                                    permanently affixed by stamping, en-                        (5) The date of the initial inspection,
                                                                    graving, or other equivalent method,                      the year (four digits) followed by the
                                                                    on the shoulder, top end or neck of the                   month (two digits) separated by a
                                                                    pressure receptacle or on a perma-                        slash, for example ‘‘2006/04’’.
                                                                    nently affixed component of the pres-                       (6) The test pressure in bar, preceded
                                                                    sure receptacle, such as a welded col-                    by the letters ‘‘PH’’ and followed by
                                                                    lar. Except for the ‘‘UN’’ mark, the                      the letters ‘‘BAR’’. The test pressure
                                                                    minimum size of the marks must be 5                       must be obtained from the results of a
                                                                    mm for pressure receptacles with a di-                    hydraulic volumetric expansion test.
                                                                    ameter greater than or equal to 140 mm                      (7) The empty or tare weight. Except
                                                                    and 2.5 mm for pressure receptacles                       for acetylene cylinders, empty weight
                                                                    with a diameter less than 140 mm. The                     is the mass of the pressure receptacle
                                                                    minimum size of the ‘‘UN’’ mark must                      in kilograms, including all integral
                                                                    be 5 mm for pressure receptacles with a                   parts (e.g., collar, neck ring, foot ring,
                                                                    diameter less than 140 mm and 10 mm                       etc.), followed by the letters ‘‘KG’’. The
                                                                    for pressure receptacles with a diame-                    empty weight does not include the
                                                                    ter of greater than or equal to 140 mm.                   mass of the valve, valve cap or valve
                                                                    The depth of the markings must not                        guard or any coating. The empty
                                                                    create harmful stress concentrations.                     weight must be expressed to three sig-
                                                                    A refillable pressure receptacle con-                     nificant figures rounded up to the last
                                                                    forming to the UN standard must be                        digit. For cylinders of less than 1 kg,
                                                                    marked as follows:                                        the empty weight must be expressed to
                                                                      (1) The UN packaging symbol.                            two significant figures rounded down
                                                                                                                              to the last digit. For acetylene cyl-
                                                                                                                              inders, the tare weight must be marked
                                                                                                                              on the cylinders in kilograms (KG).
                                                                                                                              The tare weight is the sum of the
                                                                                                                              empty weight, mass of the valve, any
                                                                                                                              coating and all permanently attached
                                                                                                                              parts (e.g. fittings and accessories)
                                                                                                                              that are not removed during filling.
                                                                                                                              The tare weight must be expressed to
                                                                                                                              two significant figures rounded down
                                                                                                                              to the last digit. The tare weight does
                                                                                                                              not include the cylinder cap or any
                                                                                                                              outlet cap or plug not permanently at-
                                                                                                                              tached to the cylinder.
                                                                       (2) The ISO standard, for example                        (8) The minimum wall thickness of
                                                                    ISO 9809–1, used for design, construc-                    the pressure receptacle in millimeters
                                                                    tion and testing. Acetylene cylinders                     followed by the letters ‘‘MM’’. This
                                                                    must be marked to indicate the porous                     mark is not required for pressure re-
                                                                    mass and the steel shell, for example:                    ceptacles with a water capacity less
                                                                    ‘‘ISO 3807–2/ISO 9809–1.’’                                than or equal to 1.0 L or for composite
                                                                       (3) The mark of the country where                      cylinders.
                                                                    the approval is granted. The letters                        (9) For pressure receptacles intended
                                                                    ‘‘USA’’ must be marked on UN pressure                     for the transport of compressed gases
                                                                    receptacles approved by the United                        and UN 1001 acetylene, dissolved, the
                                                                    States. The manufacturer must obtain                      working pressure in bar, proceeded by
                                                                    an approval number from the Associate                     the letters ‘‘PW’’.
                                                                    Administrator. The manufacturer ap-                         (10) For liquefied gases, the water ca-
                                                                    proval number must follow the country                     pacity in liters expressed to three sig-
                                                                    of approval mark, separated by a slash                    nificant digits rounded down to the
                                                                    (for example, USA/MXXXX). Pressure                        last digit, followed by the letter ‘‘L’’. If
                                                                    receptacles approved by more than one                     the value of the minimum or nominal
                                                                    national authority may contain the                        water capacity is an integer, the digits
                                                                    mark of each country of approval, sep-                    after the decimal point may be omit-
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                                                                    arated by a comma.                                        ted.
                                                                       (4) The identity mark or stamp of the                    (11) Identification of the cylinder
                                                                    IIA.                                                      thread type (e.g., 25E).

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                                                                    § 178.71                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                       (12) The country of manufacture. The                   must be placed in three groups as
                                                                    letters ‘‘USA’’ must be marked on cyl-                    shown in the example below:
                                                                    inders manufactured in the United                           (1) The top grouping contains manu-
                                                                    States.                                                   facturing marks and must appear con-
                                                                       (13) The serial number assigned by                     secutively in the sequence given in
                                                                    the manufacturer.                                         paragraphs (o)(11) through (17) of this
                                                                       (14) For steel pressure receptacles,                   section.
                                                                    the letter ‘‘H’’ showing compatibility
                                                                                                                                (2) The middle grouping contains
                                                                    of the steel, as specified in 1SO 11114–1.
                                                                       (15) Identification of aluminum alloy,                 operational marks described in para-
                                                                    if applicable.                                            graphs (o)(6) through (10) of this sec-
                                                                       (16) Stamp for nondestructive test-                    tion.
                                                                    ing, if applicable.                                         (3) The bottom grouping contains
                                                                       (17) Stamp for underwater use of                       certification marks and must appear
                                                                    composite cylinders, if applicable.                       consecutively in the sequence given in
                                                                       (p) Marking sequence. The marking re-                  paragraph (o)(1) through (5) of this sec-
                                                                    quired by paragraph (o) of this section                   tion.




                                                                       (q) Other markings. Other markings                     In addition, permanent stenciling is
                                                                    are allowed in areas other than the side                  authorized. Except when stenciled, the
                                                                    wall, provided they are made in low                       marks must be on the shoulder, top end
                                                                    stress areas and are not of a size and                    or neck of the pressure receptacle or on
                                                                    depth that will create harmful stress                     a permanently affixed component of
                                                                    concentrations. Such marks must not                       the pressure receptacle, for example a
                                                                    conflict with required marks.                             welded collar.
                                                                       (r) Marking of UN non-refillable pres-                   (1) The marking requirements and se-
                                                                    sure receptacles. Unless otherwise speci-                 quence listed in paragraphs (o)(1)
                                                                    fied in this paragraph, each UN non-re-                   through (17) of this section are re-
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                                                                    fillable pressure receptacle must be                      quired, except the markings in para-
                                                                    clearly and legibly marked as pre-                        graphs (o)(7), (8), (11) and (17) are not
                                                                    scribed in paragraph (o) of this section.                 applicable. The required serial number

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.74

                                                                    marking in paragraph (o)(13) may be                       supports, equivalent closures and other
                                                                    replaced by the batch number.                             appurtenances.
                                                                      (2) Each receptacle must be marked                        (2) Each application for design ap-
                                                                    with the words ‘‘DO NOT REFILL’’ in                       proval must be in English and contain
                                                                    letters of at least 5 mm in height.                       the following information:
                                                                      (3) A non-refillable pressure recep-                      (i) Two complete copies of all engi-
                                                                    tacle, because of its size, may sub-                      neering drawings, calculations, and
                                                                    stitute the marking required by this                      test data necessary to ensure that the
                                                                    paragraph with a label. Reduction in                      design meets the relevant specifica-
                                                                    marking size is authorized only as pre-                   tion.
                                                                    scribed in ISO 7225, Gas cylinders—Pre-                     (ii) The manufacturer’s serial number
                                                                    cautionary labels. (IBR, see § 171.7 of                   that will be assigned to each MEGC.
                                                                    this subchapter).                                           (iii) A statement as to whether the
                                                                      (4) Each non-refillable pressure re-                    design type has been examined by any
                                                                    ceptacle must also be legibly marked                      approval agency previously and judged
                                                                    by stenciling the following statement:                    unacceptable. Affirmative statements
                                                                    ‘‘Federal law forbids transportation if                   must be documented with the name of
                                                                    refilled-penalty up to $500,000 fine and 5                the approval agency, reason for non-ac-
                                                                    years in imprisonment (49 U.S.C.                          ceptance, and the nature of modifica-
                                                                    5124).’’                                                  tions made to the design type.
                                                                      (5) No person may mark a non-refill-                      (b) Actions by the approval agency. The
                                                                    able pressure receptacle as meeting the                   approval agency must review the appli-
                                                                    requirements of this section unless it                    cation for design type approval, includ-
                                                                    was manufactured in conformance with                      ing all drawings and calculations, to
                                                                    this section.                                             ensure that the design of the MEGC
                                                                    [71 FR 33887, June 12, 2006, as amended at 71             meets all requirements of the relevant
                                                                    FR 54397, Sept. 14, 2006]                                 specification and to determine whether
                                                                                                                              it is complete and conforms to the re-
                                                                    § 178.74     Approval of MEGCs.                           quirements of this section. An incom-
                                                                      (a) Application for design type ap-                     plete application will be returned to
                                                                    proval. (1) Each new MEGC design type                     the applicant with the reasons why the
                                                                    must have a design approval certifi-                      application was returned. If the appli-
                                                                    cate. An owner or manufacturer must                       cation is complete and all applicable
                                                                    apply to an approval agency that is ap-                   requirements of this section are met,
                                                                    proved by the Associate Administrator                     the approval agency must prepare a
                                                                    in accordance with subpart E of part                      MEGC design approval certificate con-
                                                                    107 of this chapter +to obtain approval                   taining the manufacturer’s name and
                                                                    of a new design. When a series of                         address, results and conclusions of the
                                                                    MEGCs       is  manufactured    without                   examination and necessary data for
                                                                    change in the design, the certificate is                  identification of the design type. If the
                                                                    valid for the entire series. The design                   Associate Administrator approves the
                                                                    approval certificate must refer to the                    Design Type Approval Certificate ap-
                                                                    prototype test report, the materials of                   plication, the approval agency and the
                                                                    construction of the manifold, the                         manufacturer must each maintain a
                                                                    standards to which the pressure recep-                    copy of the approved drawings, calcula-
                                                                    tacles are made and an approval num-                      tions, and test data for at least 20
                                                                    ber. The compliance requirements or                       years.
                                                                    test methods applicable to MEGCs as                         (c) Approval agency’s responsibilities.
                                                                    specified in this subpart may be varied                   The approval agency is responsible for
                                                                    when the level of safety is determined                    ensuring that the MEGC conforms to
                                                                    to be equivalent to or exceed the re-                     the design type approval. The approval
                                                                    quirements of this subchapter and is                      agency must:
                                                                    approved in writing by the Associate                        (1) Witness all tests required for the
                                                                    Administrator. A design approval may                      approval of the MEGC specified in this
                                                                    serve for the approval of smaller                         section and § 178.75.
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                                                                    MEGCs made of materials of the same                         (2) Ensure, through appropriate in-
                                                                    type and thickness, by the same fab-                      spection, that each MEGC is fabricated
                                                                    rication techniques and with identical                    in all respects in conformance with the

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                                                                    § 178.74                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    approved drawings, calculations, and                        (d) Manufacturers’ responsibilities. The
                                                                    test data.                                                manufacturer is responsible for compli-
                                                                       (3) Determine and ensure that the                      ance with the applicable specifications
                                                                    MEGC is suitable for its intended use                     for the design and construction of
                                                                    and that it conforms to the require-                      MEGCs. The manufacturer of a MEGC
                                                                    ments of this subchapter.                                 must:
                                                                       (4) Apply its name, identifying mark                     (1) Comply with all the requirements
                                                                    or identifying number, and the date the                   of the applicable ISO standard specified
                                                                    approval was issued, to the metal iden-                   in § 178.71;
                                                                    tification marking plate attached to                        (2) Obtain and use an approval agen-
                                                                    the MEGC upon successful completion                       cy to review the design, construction
                                                                    of all requirements of this subpart.                      and certification of the MEGC;
                                                                    Any approvals by the Associate Admin-                       (3) Provide a statement in the manu-
                                                                    istrator authorizing design or con-                       facturers’ data report certifying that
                                                                    struction alternatives (Alternate Ar-
                                                                                                                              each MEGC manufactured complies
                                                                    rangements) of the MEGC (see para-
                                                                                                                              with the relevant specification and all
                                                                    graph (a) of this section) must be indi-
                                                                    cated on the metal identification plate                   the applicable requirements of this
                                                                    as specified in § 178.75(j).                              subchapter; and
                                                                       (5) Prepare an approval certificate                      (4) Retain records for the MEGCs for
                                                                    for each MEGC or, in the case of a se-                    at least 20 years. When required by the
                                                                    ries of identical MEGCs manufactured                      specification, the manufacturer must
                                                                    to a single design type, for each series                  provide copies of the records to the ap-
                                                                    of MEGCs. The approval certificate                        proval agency, the owner or lessee of
                                                                    must include all of the following infor-                  the MEGC, and to a representative of
                                                                    mation:                                                   DOT, upon request.
                                                                       (i) The information displayed on the                     (e) Denial of application for approval.
                                                                    metal identification plate required by                    If the Associate Administrator finds
                                                                    § 178.75(j);                                              that the MEGC will not be approved for
                                                                       (ii) The results of the applicable                     any reason, the Associate Adminis-
                                                                    framework test specified in ISO 1496–3                    trator will notify the applicant in writ-
                                                                    (IBR, see § 171.7 of this subchapter);                    ing and provide the reason for the de-
                                                                       (iii) The results of the initial inspec-               nial. The manufacturer may request
                                                                    tion and test specified in paragraph (h)                  that the Associate Administrator re-
                                                                    of this section;                                          consider the decision. The application
                                                                       (iv) The results of the impact test                    request must—
                                                                    specified in § 178.75(i)(4);                                (1) Be written in English and filed
                                                                       (v) Certification documents verifying                  within 90 days of receipt of the deci-
                                                                    that the cylinders and tubes conform                      sion;
                                                                    to the applicable standards; and                            (2) State in detail any alleged errors
                                                                       (vi) A statement that the approval                     of fact and law; and
                                                                    agency certifies the MEGC in accord-                        (3) Enclose any additional informa-
                                                                    ance with the procedures in this sec-                     tion needed to support the request to
                                                                    tion and that the MEGC is suitable for                    reconsider.
                                                                    its intended purpose and meets the re-                      (f) Appeal. (1) A manufacturer whose
                                                                    quirements of this subchapter. When a                     reconsideration request is denied may
                                                                    series of MEGCs is manufactured with-
                                                                                                                              appeal to the PHMSA Administrator.
                                                                    out change in the design type, the cer-
                                                                                                                              The appeal must—
                                                                    tificate may be valid for the entire se-
                                                                    ries of MEGCs representing a single de-                     (i) Be in writing and filed within 90
                                                                    sign type. The approval number must                       days of receipt of the Associate Admin-
                                                                    consist of the distinguishing sign or                     istrator s decision on reconsideration;
                                                                    mark of the country (‘‘USA’’ for the                        (ii) State in detail any alleged errors
                                                                    United States of America) where the                       of fact and law;
                                                                    approval was granted and a registra-                        (iii) Enclose any additional informa-
                                                                                                                              tion needed to support the appeal; and
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                                                                    tion number.
                                                                       (6) Retain on file a copy of each ap-                    (iv) State in detail the modification
                                                                    proval certificate for at least 20 years.                 of the final decision sought.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.74

                                                                      (2) The Administrator will grant or                       (i) Retain a set of the approved re-
                                                                    deny the relief and inform the appel-                     vised drawings, calculations, and data
                                                                    lant in writing of the decision. The Ad-                  as specified in § 178.69(b)(4) for at least
                                                                    ministrator’s decision is the final ad-                   20 years;
                                                                    ministrative action.                                        (ii) Ensure through appropriate in-
                                                                      (g) Modifications to approved MEGCs.                    spection that all modifications con-
                                                                    (1) Prior to modification of any ap-                      form to the revised drawings, calcula-
                                                                    proved MEGC that may affect conform-                      tions, and test data; and
                                                                    ance and safe use, and that may in-                         (iii) Determine the extent to which
                                                                    volve a change to the design type or af-                  retesting of the modified MEGC is nec-
                                                                    fect its ability to retain the hazardous                  essary based on the nature of the pro-
                                                                    material     in    transportation,   the
                                                                                                                              posed modification, and ensure that all
                                                                    MEGC’s owner must inform the ap-
                                                                                                                              required retests are satisfactorily per-
                                                                    proval agency that prepared the initial
                                                                                                                              formed.
                                                                    approval certificate for the MEGC or, if
                                                                    the initial approval agency is unavail-                     (h) Termination of Approval Certificate.
                                                                    able, another approval agency, of the                     (1) The Associate Administrator may
                                                                    nature of the modification and request                    terminate an approval issued under
                                                                    certification of the modification. The                    this section if he or she determines
                                                                    owner must supply the approval agency                     that—
                                                                    with all revised drawings, calculations,                    (i) Because of a change in cir-
                                                                    and test data relative to the intended                    cumstances, the approval no longer is
                                                                    modification. The MEGC’s owner must                       needed or no longer would be granted if
                                                                    also provide a statement as to whether                    applied for;
                                                                    the intended modification has been ex-                      (ii) Information upon which the ap-
                                                                    amined and determined to be unaccept-                     proval was based is fraudulent or sub-
                                                                    able by any approval agency. The writ-                    stantially erroneous;
                                                                    ten statement must include the name                         (iii) Termination of the approval is
                                                                    of the approval agency, the reason for                    necessary     to    adequately      protect
                                                                    non-acceptance, and the nature of                         against risks to life and property; or
                                                                    changes made to the modification since                      (iv) The MEGC does not meet the
                                                                    its original rejection.                                   specification.
                                                                      (2) The approval agency must review
                                                                                                                                (2) Before an approval is terminated,
                                                                    the request for modification. If the ap-
                                                                                                                              the Associate Administrator will pro-
                                                                    proval agency determines that the pro-
                                                                                                                              vide the person—
                                                                    posed modification does not conform to
                                                                    the relevant specification, the approval                    (i) Written notice of the facts or con-
                                                                    agency must reject the request in ac-                     duct believed to warrant the termi-
                                                                    cordance with paragraph (d) of this sec-                  nation;
                                                                    tion. If the approval agency determines                     (ii) An opportunity to submit oral
                                                                    that the proposed modification con-                       and written evidence; and
                                                                    forms fully with the relevant specifica-                    (3) An opportunity to demonstrate or
                                                                    tion, the request is accepted. If modi-                   achieve compliance with the applicable
                                                                    fication to an approved MEGC alters                       requirements.
                                                                    any information on the approval cer-                        (i) Imminent Danger. If the Associate
                                                                    tificate, the approval agency must pre-                   Administrator determines that a cer-
                                                                    pare a new approval certificate for the                   tificate of approval must be terminated
                                                                    modified MEGC and submit the certifi-                     to preclude a significant and imminent
                                                                    cate to the Associate Administrator for                   adverse effect on public safety, the As-
                                                                    approval. After receiving approval                        sociate Administrator may terminate
                                                                    from the Associate Administrator, the                     the certificate immediately. In such
                                                                    approval agency must ensure that any                      circumstances, the opportunities of
                                                                    necessary changes are made to the                         paragraphs (h)(2) and (3) of this section
                                                                    metal identification plate. A copy of                     need not be provided prior to termi-
                                                                    each newly issued approval certificate                    nation of the approval, but must be
                                                                    must be retained by the approval agen-                    provided as soon as practicable there-
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                                                                    cy and the MEGC’s owner for at least
                                                                                                                              after.
                                                                    20 years. The approval agency must
                                                                    perform the following activities:                         [71 FR 33890, June 12, 2006]

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                                                                    § 178.75                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    § 178.75 Specifications for MEGCs.                        loaded to its maximum permissible
                                                                       (a) General. Each MEGC must meet                       gross mass. The MEGC must be de-
                                                                    the requirements of this section. In a                    signed to be loaded onto a transport ve-
                                                                    MEGC that meets the definition of a                       hicle or vessel and equipped with skids,
                                                                    ‘‘container’’ within the terms of the                     mountings or accessories to facilitate
                                                                    International Convention for Safe Con-                    mechanical handling.
                                                                    tainers (CSC) must meet the require-                         (2) MEGCs must be designed, manu-
                                                                    ments of the CSC as amended and 49                        factured and equipped to withstand,
                                                                    CFR parts 450 through 453, and must                       without loss of contents, all normal
                                                                    have a CSC approval plate.                                handling and transportation condi-
                                                                       (b) Alternate Arrangements. The tech-                  tions. The design must take into ac-
                                                                    nical     requirements     applicable   to                count the effects of dynamic loading
                                                                    MEGCs may be varied when the level of                     and fatigue.
                                                                    safety is determined to be equivalent                        (3) Each pressure receptacle of a
                                                                    to or exceed the requirements of this                     MEGC must be of the same design type,
                                                                    subchapter. Such an alternate arrange-                    seamless steel, and constructed and
                                                                    ment must be approved in writing by                       tested according to one of the following
                                                                    the Associate Administrator. MEGCs                        ISO standards:
                                                                    approved to an Alternate Arrangement                         (i) ISO 9809–1: Gas cylinders—Refill-
                                                                    must be marked as required by para-                       able seamless steel gas cylinders—De-
                                                                    graph (j) of this section.                                sign, construction and testing—Part 1:
                                                                       (c) Definitions. The following defini-                 Quenched and tempered steel cylinders
                                                                    tions apply:                                              with tensile strength less than 1 100
                                                                       Leakproofness test means a test using                  MPa. (IBR, see § 171.7 of this sub-
                                                                    gas subjecting the pressure receptacles                   chapter);
                                                                    and the service equipment of the MEGC                        (ii) ISO 9809–2: Gas cylinders—Refill-
                                                                    to an effective internal pressure of not                  able seamless steel gas cylinders—De-
                                                                    less than 20% of the test pressure.                       sign, construction and testing—Part 2:
                                                                       Manifold means an assembly of piping                   Quenched and tempered steel cylinders
                                                                    and valves connecting the filling and/or                  with tensile strength greater than or
                                                                    discharge openings of the pressure re-                    equal to 1 100 MPa. (IBR, see § 171.7 of
                                                                    ceptacles.                                                this subchapter);
                                                                       Maximum permissible gross mass or                         (iii) ISO 9809–3: Gas cylinders—Refill-
                                                                    MPGM means the heaviest load author-                      able seamless steel gas cylinders—De-
                                                                    ized for transport (sum of the tare                       sign, construction and testing—Part 3:
                                                                    mass of the MEGC, service equipment                       Normalized steel cylinders. (IBR, see
                                                                    and pressure receptacle).                                 § 171.7 of this subchapter); or
                                                                       Service equipment means manifold sys-                     (iv) ISO 11120: Gas cylinders—Refill-
                                                                    tem (measuring instruments, piping                        able seamless steel tubes of water ca-
                                                                    and safety devices).                                      pacity between 150 L and 3000 L—De-
                                                                       Shut-off valve means a valve that                      sign, construction and testing. (IBR,
                                                                    stops the flow of gas.                                    see § 171.7 of this subchapter).
                                                                       Structural equipment means the rein-                      (4) Pressure receptacles of MEGCs,
                                                                    forcing, fastening, protective and stabi-                 fittings, and pipework must be con-
                                                                    lizing members external to the pres-                      structed of a material that is compat-
                                                                    sure receptacles.                                         ible with the hazardous materials in-
                                                                       (d) General design and construction re-                tended to be transported, as specified
                                                                    quirements. (1) The MEGC must be capa-                    in this subchapter.
                                                                    ble of being loaded and discharged                           (5) Contact between dissimilar met-
                                                                    without the removal of its structural                     als that could result in damage by gal-
                                                                    equipment. It must possess stabilizing                    vanic action must be prevented by ap-
                                                                    members external to the pressure re-                      propriate means.
                                                                    ceptacles to provide structural integ-                       (6) The materials of the MEGC, in-
                                                                    rity for handling and transport. MEGCs                    cluding any devices, gaskets, and ac-
                                                                    must be designed and constructed with                     cessories, must have no adverse effect
                                                                    supports to provide a secure base dur-                    on the gases intended for transport in
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                                                                    ing transport and with lifting and tie-                   the MEGC.
                                                                    down attachments that are adequate                           (7) MEGCs must be designed to with-
                                                                    for lifting the MEGC including when                       stand, without loss of contents, at

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.75

                                                                    least the internal pressure due to the                    centration     of    harmful    localized
                                                                    contents, and the static, dynamic and                     stresses.
                                                                    thermal loads during normal condi-                          (e) Service equipment. (1) Service
                                                                    tions of handling and transport. The                      equipment must be arranged so that it
                                                                    design must take into account the ef-                     is protected from mechanical damage
                                                                    fects of fatigue, caused by repeated ap-                  by external forces during handling and
                                                                    plication of these loads through the ex-                  transportation. When the connections
                                                                    pected life of the MEGC.                                  between the frame and the pressure re-
                                                                      (8) MEGCs and their fastenings must,                    ceptacles allow relative movement be-
                                                                    under the maximum permissible load,                       tween the subassemblies, the equip-
                                                                    be capable of withstanding the fol-                       ment must be fastened to allow move-
                                                                    lowing separately applied static forces                   ment to prevent damage to any work-
                                                                    (for calculation purposes, acceleration                   ing part. The manifolds, discharge fit-
                                                                    due to gravity (g) = 9.81 m/s2):                          tings (pipe sockets, shut-off devices),
                                                                      (i) In the direction of travel: 2g                      and shut-off valves must be protected
                                                                    (twice the MPGM multiplied by the ac-                     from damage by external forces. Mani-
                                                                    celeration due to gravity);                               fold piping leading to shut-off valves
                                                                      (ii) Horizontally at right angles to                    must be sufficiently flexible to protect
                                                                    the direction of travel: 1g (the MPGM                     the valves and the piping from shear-
                                                                    multiplied by the acceleration due to                     ing, or releasing the pressure recep-
                                                                    gravity. When the direction of travel is                  tacle contents. The filling and dis-
                                                                    not clearly determined, the forces must                   charge devices, including flanges or
                                                                    be equal to twice the MPGM);                              threaded plugs, and any protective caps
                                                                      (iii) Vertically upwards: 1g (the                       must be capable of being secured
                                                                    MPGM multiplied by the acceleration                       against unintended opening.
                                                                    due to gravity); and                                        (2) Each pressure receptacle intended
                                                                                                                              for the transport of Division 2.3 gases
                                                                      (iv) Vertically downwards: 2g (twice
                                                                                                                              must be equipped with an individual
                                                                    the MPGM (total loading including the
                                                                                                                              shut-off valve. The manifold for Divi-
                                                                    effect of gravity) multiplied by the ac-
                                                                                                                              sion 2.3 liquefied gases must be de-
                                                                    celeration due to gravity.
                                                                                                                              signed so that each pressure receptacle
                                                                      (9) Under each of the forces specified
                                                                                                                              can be filled separately and be kept
                                                                    in paragraph (d)(8) of this section, the
                                                                                                                              isolated by a valve capable of being
                                                                    stress at the most severely stressed
                                                                                                                              closed during transit. For Division 2.1
                                                                    point of the pressure receptacles must
                                                                                                                              gases, the pressure receptacles must be
                                                                    not exceed the values given in the ap-
                                                                                                                              isolated by an individual shut-off valve
                                                                    plicable design specifications (e.g., ISO
                                                                                                                              into assemblies of not more than 3,000
                                                                    11120).                                                   L.
                                                                      (10) Under each of the forces specified                   (3) For MEGC filling and discharge
                                                                    in paragraph (d)(8) of this section, the                  openings:
                                                                    safety factor for the framework and                         (i) Two valves in series must be
                                                                    fastenings must be as follows:                            placed in an accessible position on each
                                                                      (i) For steels having a clearly defined                 discharge and filling pipe. One of the
                                                                    yield point, a safety factor of 1.5 in re-                valves may be a backflow prevention
                                                                    lation    to    the   guaranteed     yield                valve. (ii) The filling and discharge de-
                                                                    strength; or                                              vices may be equipped to a manifold.
                                                                      (ii) For steels with no clearly defined                   (iii) For sections of piping which can
                                                                    yield point, a safety factor of 1.5 in re-                be closed at both ends and where a liq-
                                                                    lation to the guaranteed 0.2 percent                      uid product can be trapped, a pressure-
                                                                    proof strength and, for austenitic                        relief valve must be provided to pre-
                                                                    steels, the 1 percent proof strength.                     vent excessive pressure build-up.
                                                                      (11) MEGCs must be capable of being                       (iv) The main isolation valves on a
                                                                    electrically grounded to prevent elec-                    MEGC must be clearly marked to indi-
                                                                    trostatic discharge when intended for                     cate their directions of closure. All
                                                                    flammable gases.                                          shutoff valves must close by a clock-
                                                                      (12) The pressure receptacles of a                      wise motion of the handwheel.
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                                                                    MEGC must be secured in a manner to                         (v) Each shut-off valve or other
                                                                    prevent movement that could result in                     means of closure must be designed and
                                                                    damage to the structure and con-                          constructed to withstand a pressure

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                                                                    § 178.75                                                              49 CFR Ch. I (10–1–09 Edition)

                                                                    equal to or greater than 1.5 times the                    shut-off valves are interlocked so that
                                                                    test pressure of the MEGC.                                at least one of the duplicate devices is
                                                                      (vi) All shut-off valves with screwed                   always operable and capable of meeting
                                                                    spindles must close by a clockwise mo-                    the requirements of paragraph (f)(1) of
                                                                    tion of the handwheel. For other shut-                    this section. No obstruction is per-
                                                                    off valves, the open and closed posi-                     mitted in an opening leading to or
                                                                    tions and the direction of closure must                   leaving from a vent or pressure-relief
                                                                    be clearly shown.                                         device that might restrict or cut-off
                                                                      (vii) All shut-off valves must be de-                   the flow from the pressure receptacle
                                                                    signed and positioned to prevent unin-                    to that device. The opening through all
                                                                    tentional opening.                                        piping and fittings must have at least
                                                                      (viii) Ductile metals must be used in                   the same flow area as the inlet of the
                                                                    the construction of valves or acces-                      pressure relief device to which it is
                                                                    sories.                                                   connected. The nominal size of the dis-
                                                                      (4) The piping must be designed, con-                   charge piping must be at least as large
                                                                    structed and installed to avoid damage                    as that of the pressure relief device.
                                                                    due to expansion and contraction, me-                       (3) Location of pressure-relief de-
                                                                    chanical shock and vibration. Joints in                   vices: For liquefied gases, each pres-
                                                                    tubing must be brazed or have an                          sure relief device must, under max-
                                                                    equally strong metal union. The melt-                     imum filling conditions, be in commu-
                                                                    ing point of brazing materials must be                    nication with the vapor space of the
                                                                    no lower than 525 °C (977 °F). The rated                  pressure receptacles. The devices, when
                                                                    pressure of the service equipment and                     installed, must be arranged to ensure
                                                                    of the manifold must be not less than                     the escaping vapor is discharged up-
                                                                    two-thirds of the test pressure of the                    wards and unrestrictedly to prevent
                                                                    pressure receptacles.                                     impingement of escaping gas or liquid
                                                                      (f) Pressure relief devices. Each pres-                 upon the MEGC, its pressure recep-
                                                                    sure receptacle must be equipped with                     tacles or personnel. For flammable,
                                                                    one or more pressure relief devices as                    pyrophoric and oxidizing gases, the es-
                                                                    specified in § 173.301(f) of this sub-                    caping gas must be directed away from
                                                                    chapter. When pressure relief devices                     the pressure receptacle in such a man-
                                                                    are installed, each pressure receptacle                   ner that it cannot impinge upon the
                                                                    or group of pressure receptacles of a                     other pressure receptacles. Heat resist-
                                                                    MEGC that can be isolated must be                         ant protective devices that deflect the
                                                                    equipped with one or more pressure re-                    flow of gas are permissible provided the
                                                                    lief devices. Pressure relief devices                     required pressure relief device capacity
                                                                    must be of a type that will resist dy-                    is not reduced. Arrangements must be
                                                                    namic forces including liquid surge and                   made to prevent access to the pressure
                                                                    must be designed to prevent the entry                     relief devices by unauthorized persons
                                                                    of foreign matter, the leakage of gas                     and to protect the devices from damage
                                                                    and the development of any dangerous                      caused by rollover.
                                                                    excess pressure.                                            (g) Gauging devices. When a MEGC is
                                                                      (1) The size of the pressure relief de-                 intended to be filled by mass, it must
                                                                    vices: CGA S–1.1 (IBR, see § 171.7 of this                be equipped with one or more gauging
                                                                    subchapter) must be used to determine                     devices. Glass level-gauges and gauges
                                                                    the relief capacity of individual pres-                   made of other fragile material are pro-
                                                                    sure receptacles.                                         hibited.
                                                                      (2) Connections to pressure-relief de-                    (h) MEGC supports, frameworks, lifting
                                                                    vices: Connections to pressure relief                     and tie-down attachments. (1) MEGCs
                                                                    devices must be of sufficient size to en-                 must be designed and constructed with
                                                                    able the required discharge to pass un-                   a support structure to provide a secure
                                                                    restricted to the pressure relief device.                 base during transport. MEGCs must be
                                                                    A shut-off valve installed between the                    protected against damage to the pres-
                                                                    pressure receptacle and the pressure re-                  sure receptacles and service equipment
                                                                    lief device is prohibited, except where                   resulting from lateral and longitudinal
                                                                    duplicate devices are provided for                        impact and overturning. The forces
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                                                                    maintenance or other reasons, and the                     specified in paragraph (d)(8) of this sec-
                                                                    shut-off valves serving the devices ac-                   tion, and the safety factor specified in
                                                                    tually in use are locked open, or the                     paragraph (d)(10) of this section must

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                                 § 178.75

                                                                    be considered in this aspect of the de-                   and test). This initial inspection and
                                                                    sign. Skids, frameworks, cradles or                       test of an MEGC must include the fol-
                                                                    other similar structures are accept-                      lowing:
                                                                    able. If the pressure receptacles and                        (1) A check of the design characteris-
                                                                    service equipment are so constructed                      tics.
                                                                    as to withstand impact and over-                             (2) An external examination of the
                                                                    turning, additional protective support                    MEGC and its fittings, taking into ac-
                                                                    structure is not required (see para-                      count the hazardous materials to be
                                                                    graph (h)(4) of this section).                            transported.
                                                                       (2) The combined stresses caused by
                                                                                                                                 (3) A pressure test performed at the
                                                                    pressure receptacle mountings (e.g.
                                                                                                                              test       pressures     specified     in
                                                                    cradles, frameworks, etc.) and MEGC
                                                                                                                              § 173.304b(b)(1) and (2) of this sub-
                                                                    lifting and tie-down attachments must
                                                                                                                              chapter. The pressure test of the mani-
                                                                    not cause excessive stress in any pres-
                                                                    sure receptacle. Permanent lifting and                    fold may be performed as a hydraulic
                                                                    tie-down        attachments       must    be              test or by using another liquid or gas.
                                                                    equipped to all MEGCs. Any welding of                     A leakproofness test and a test of the
                                                                    mountings or attachments onto the                         satisfactory operation of all service
                                                                    pressure receptacles is prohibited.                       equipment must also be performed be-
                                                                       (3) The effects of environmental cor-                  fore the MEGC is placed into service.
                                                                    rosion must be taken into account in                      When the pressure receptacles and
                                                                    the design of supports and frameworks.                    their fittings have been pressure-tested
                                                                       (4) When MEGCs are not protected                       separately, they must be subjected to a
                                                                    during transport as specified in para-                    leakproof test after assembly.
                                                                    graph (h)(1) of this section, the pres-                      (4) An MEGC that meets the defini-
                                                                    sure receptacles and service equipment                    tion of ‘‘container’’ in the CSC (see 49
                                                                    must be protected against damage re-                      CFR 450.3(a)(2)) must be subjected to an
                                                                    sulting from lateral or longitudinal im-                  impact test using a prototype rep-
                                                                    pact or overturning. External fittings                    resenting each design type. The proto-
                                                                    must be protected against release of                      type MEGC must be shown to be capa-
                                                                    the pressure receptacles’ contents upon                   ble of absorbing the forces resulting
                                                                    impact or overturning of the MEGC on                      from an impact not less than 4 times (4
                                                                    its fittings. Particular attention must                   g) the MPGM of the fully loaded
                                                                    be paid to the protection of the mani-                    MEGC, at a duration typical of the me-
                                                                    fold. Examples of protection include:                     chanical shocks experienced in rail
                                                                       (i) Protection against lateral impact,                 transport. A listing of acceptable
                                                                    which may consist of longitudinal bars;                   methods for performing the impact test
                                                                       (ii) Protection against overturning,                   is provided in the UN Recommenda-
                                                                    which may consist of reinforcement                        tions (IBR, see § 171.7 of this sub-
                                                                    rings or bars fixed across the frame;                     chapter).
                                                                       (iii) Protection against rear impact,                     (j) Marking. (1) Each MEGC must be
                                                                    which may consist of a bumper or                          equipped with a corrosion resistant
                                                                    frame;                                                    metal plate permanently attached to
                                                                       (iv) Protection of the pressure recep-                 the MEGC in a conspicuous place read-
                                                                    tacles and service equipment against                      ily accessible for inspection. The pres-
                                                                    damage from impact or overturning by                      sure receptacles must be marked ac-
                                                                    use of an ISO frame according to the                      cording to this section. Affixing the
                                                                    relevant provisions of ISO 1496–3. (IBR,                  metal plate to a pressure receptacle is
                                                                    see § 171.7 of this subchapter).                          prohibited. At a minimum, the fol-
                                                                       (i) Initial inspection and test. The pres-
                                                                                                                              lowing information must be marked on
                                                                    sure receptacles and items of equip-
                                                                                                                              the plate by stamping or by any other
                                                                    ment of each MEGC must be inspected
                                                                                                                              equivalent method:
                                                                    and tested before being put into service
                                                                    for the first time (initial inspection                    Country of manufacture
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                                                                    Pt. 178, Subpt. C, App. A                                             49 CFR Ch. I (10–1–09 Edition)

                                                                                             UN                               Total water capacity lll liters
                                                                                                                              Initial pressure test date and identi-
                                                                                                                              fication of the Approval Agency
                                                                                                                              Date and type of most recent periodic
                                                                                                                              tests
                                                                                                                              Year lll Monthlll Type lll
                                                                                                                              (e.g. 2004–05, AE/UE, where ‘‘AE’’ rep-
                                                                                                                              resents acoustic emission and ‘‘UE’’
                                                                                                                              represents ultrasonic examination)
                                                                                                                                Stamp of the approval agency who
                                                                                                                              performed or witnessed the most recent
                                                                                                                              test
                                                                                                                                (2) The following information must
                                                                    Approval Country                                          be marked on a metal plate firmly se-
                                                                    Approval Number                                           cured to the MEGC:
                                                                    Alternate Arrangements (see § 178.75(b))                  Name of the operator
                                                                    MEGC Manufacturer’s name or mark                          Maximum permissible load mass lll
                                                                    MEGC’s serial number                                      kg
                                                                    Approval agency (Authorized body for                      Working pressure at 15 °C: lll bar
                                                                    the design approval)                                      gauge
                                                                    Year of manufacture                                       Maximum permissible gross mass
                                                                    Test pressure: lll bar gauge                              (MPGM) lll kg
                                                                    Design temperature range lll °C to                        Unladen (tare) mass lll kg
                                                                    lll °C                                                    [71 FR 33892, June 12, 2006, as amended at 73
                                                                    Number of pressure receptacles lll                        FR 4719, Jan. 28, 2008]


                                                                         APPENDIX A TO SUBPART C OF PART 178—ILLUSTRATIONS: CYLINDER TENSILE
                                                                                                       SAMPLE
                                                                     The following figures illustrate the recommended locations for test specimens taken from
                                                                    welded cylinders:
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                                                                                                                         900
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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT Pt. 178, Subpt. C, App. A
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                                                                    Pt. 178, Subpt. C, App. A                                             49 CFR Ch. I (10–1–09 Edition)
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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT Pt. 178, Subpt. C, App. A
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                                                                    Pt. 178, Subpt. C, App. A                                             49 CFR Ch. I (10–1–09 Edition)
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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT Pt. 178, Subpt. C, App. A




                                                                    [67 FR 51654, Aug. 8, 2002]
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                                                                                                                         905
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                                                                    §§ 178.251—178.253–5                                                                             49 CFR Ch. I (10–1–09 Edition)

                                                                               Subparts D–G [Reserved]                                                   § 178.255–3     Expansion domes.
                                                                                                                                                           (a) Expansion domes, if applied, must
                                                                          Subpart H—Specifications for                                                   have a minimum capacity of one per-
                                                                                Portable Tanks                                                           cent of the combined capacity of the
                                                                                                                                                         tank and dome.
                                                                      SOURCE: 29 FR 18972, Dec. 29, 1964, unless                                           (b) [Reserved]
                                                                    otherwise noted. Redesignated at 32 FR 5606,
                                                                    Apr. 5, 1967.                                                                        § 178.255–4 Closures for manholes and
                                                                                                                                                             domes.
                                                                    §§ 178.251—178.253–5                          [Reserved]                               (a) The manhole cover shall be de-
                                                                    § 178.255 Specification 60; steel port-                                              signed to provide a secure closure of
                                                                        able tanks.                                                                      the manhole. All covers, not hinged to
                                                                                                                                                         the tanks, shall be attached to the out-
                                                                    § 178.255–1              General requirements.                                       side of the dome by at least 1⁄8 inch
                                                                                                                                                         chain or its equivalent. Closures shall
                                                                      (a) Tanks must be of fusion welded
                                                                                                                                                         be made tight against leakage of vapor
                                                                    construction, cylindrical in shape with
                                                                                                                                                         and liquid by use of gaskets of suitable
                                                                    seamless heads concave to the pres-
                                                                                                                                                         material.
                                                                    sure. Tank shells may be of seamless
                                                                    construction.                                                                          (b) [Reserved]
                                                                      (b) Tanks must be designed, con-
                                                                                                                                                         § 178.255–5     Bottom discharge outlets.
                                                                    structed, certified, and stamped in ac-
                                                                    cordance with Section VIII of the                                                      (a) Bottom discharge outlets prohib-
                                                                    ASME Code (IBR, see § 171.7 of this sub-                                             ited, except on tanks used for ship-
                                                                    chapter).                                                                            ments of sludge acid and alkaline cor-
                                                                      (c) Tanks including all permanent at-                                              rosive liquids.
                                                                    tachments must be postweld heat                                                        (b) If installed, bottom outlets or
                                                                    treated as a unit.                                                                   bottom washout chambers shall be of
                                                                      (d) Requirements concerning types of                                               metal not subject to rapid deteriora-
                                                                    valves, retesting, and qualification of                                              tion by the lading, and each shall be
                                                                    portable tanks contained in §§ 173.32                                                provided with a valve or plug at its
                                                                    and 173.315 of this chapter must be ob-                                              upper end and liquid-tight closure at it
                                                                    served.                                                                              lower end. Each valve or plug shall be
                                                                                                                                                         designed to insure against unseating
                                                                    [29 FR 18972, Dec. 29, 1964. Redesignated at 32
                                                                                                                                                         due to stresses or shocks incident to
                                                                    FR 5606, Apr. 5, 1967, and amended by Amdt.
                                                                    178–7, 34 FR 18250, Nov. 14, 1969; 68 FR 75750,                                      transportation. Bottom outlets shall be
                                                                    Dec. 31, 2003]                                                                       adequately protected against handling
                                                                                                                                                         damage and outlet equipment must not
                                                                    § 178.255–2              Material.                                                   extend to within less than one inch of
                                                                                                                                                         the bottom bearing surface of the skids
                                                                      (a) Material used in the tank must be
                                                                                                                                                         or tank mounting.
                                                                    steel of good weldable quality and con-
                                                                    form with the requirements in Sections                                               [29 FR 18972, Dec. 29, 1964. Redesignated at 32
                                                                    V, VIII, and IX of the ASME Code (IBR,                                               FR 5606, Apr. 5, 1967, as amended by Amdt.
                                                                    see § 171.7 of this subchapter).                                                     178–104, 59 FR 49135, Sept. 26, 1994]
                                                                      (b) The minimum thickness of metal,
                                                                    exclusive of lining material, for shell                                              § 178.255–6 Loading and unloading ac-
                                                                    and heads of tanks shall be as follows:                                                  cessories.
                                                                                                                                                           (a) When installed, gauging, loading
                                                                                                                                        Minimum
                                                                                           Tank capacity                                thickness        and air inlet devices, including their
                                                                                                                                          (inch)         valves, shall be provided with adequate
                                                                                                                                                         means for their secure closure; and
                                                                    Not more than 1,200 gallons ...............................                14  ⁄
                                                                    Over 1,200 to 1,800 gallons ................................               ⁄
                                                                                                                                              5 16       means shall also be provided for the
                                                                    Over 1,800 gallons ..............................................          38  ⁄     closing of pipe connections of valves.
                                                                                                                                                           (b) Interior heater coils, if installed,
                                                                    [29 FR 18972, Dec. 29, 1964. Redesignated at 32                                      must be of extra heavy pipe and so con-
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                                                                    FR 5606, Apr. 5, 1967, and amended by Amdt.                                          structed that breaking off of exterior
                                                                    178–7, 34 FR 18250, Nov. 14, 1969; 68 FR 75750,                                      connections will not cause leakage of
                                                                    Dec. 31, 2003]                                                                       tanks.

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                                                                    Pipeline and Hazardous Materials Safety Admin., DOT                                         § 178.255–13

                                                                    § 178.255–7 Protection of valves and                      devices shall be deemed to comply with
                                                                         accessories.                                         this requirement.
                                                                       (a) All valves, fittings, accessories,                   (b) All tank mountings such as skids,
                                                                    safety devices, gauging devices, and the                  fastenings, brackets, cradles, lifting
                                                                    like shall be adequately protected                        lugs, etc., intended to carry loadings
                                                                    against mechanical damage by a hous-                      shall be permanently secured to tanks
                                                                    ing closed with a cover plate.                            in accordance with the requirements
                                                                       (b) Protective housing shall comply                    under which the tanks are fabricated,
                                                                    with the requirements under which the                     and shall be designed with a factor of
                                                                    tanks are fabricated with respect to de-                  safety of four, and built to withstand
                                                                    sign and construction, and shall be de-                   loadings in any direction equal to two
                                                                    signed with a minimum factor of safety                    times the weight of the tanks and at-
                                                                    of four to withstand loadings in any di-                  tachments when filled to the maximum
                                                                    rection equal to two times the weight                     permissible loaded weight.
                                                                    of the tank and attachments when                            (c) Lifting lugs or side hold-down
                                                                    filled with water.                                        lugs shall be provided on the tank
                                                                                                                              mountings in a manner suitable for at-
                                                                    § 178.255–8 Safety devices.                               taching lifting gear and hold-down de-
                                                                       (a) See § 173.315(i) of this subchapter.               vices. Lifting lugs and hold-down lugs
                                                                       (b) [Reserved]                                         welded directly to the tank shall be of
                                                                                                                              the pad-eye type. Doubling plates weld-
                                                                    [Amdt. 178–83, 50 FR 11066, Mar. 19, 1985]                ed to the tank and located at the
                                                                    § 178.255–9 Compartments.                                 points of support shall be deemed to
                                                                                                                              comply with this requirement.
                                                                       (a) When the interior of the tank is                     (d) All tank mountings shall be so de-
                                                                    divided into compartments, each com-                      signed as to prevent the concentration
                                                                    partment shall be designed, con-                          of excessive loads on the tank shell.
                                                                    structed and tested as a separate tank.
                                                                    Thickness of shell and compartment                        § 178.255–12     Pressure test.
                                                                    heads shall be determined on the basis
                                                                                                                                (a) Each completed portable tank
                                                                    of total tank capacity.
                                                                                                                              prior to application of lining shall be
                                                                       (b) [Reserved]
                                                                                                                              tested before being put into transpor-
                                                                    § 178.255–10 Lining.                                      tation service by completely filling the
                                                                                                                              tank with water or other liquid having
                                                                       (a) If a lining is required, the mate-
                                                                                                                              a similar viscosity, the temperature of
                                                                    rial used for lining the tank shall be
                                                                                                                              which shall not exceed 100 °F during
                                                                    homogeneous, nonporous, imperforate
                                                                                                                              the test, and applying a pressure of 60
                                                                    when applied, not less elastic than the
                                                                                                                              psig. The tank shall be capable of hold-
                                                                    metal of the tank proper. It shall be of
                                                                                                                              ing the prescribed pressure for at least
                                                                    substantially uniform thickness, not
                                                                                                                              10 minutes without leakage, evidence
                                                                    less than 1⁄32 inch thick if metallic, and
                                                                                                                              of impending failure, or failure. All clo-
                                                                    not less than 1⁄16 inch thick if non-
                                                                                                                              sures shall be in place while the test is
                                                                    metallic, and shall be directly bonded
                                                                                                                              made and the pressure shall be gauged
                                                                    or attached by other equally satisfac-
                                                                                                                              at the top of the tank. Safety devices
                                                                    tory means. Rubber lining shall be not
                                                                                                                              and/or vents shall be plugged during
                                                                    less than 3⁄16 inch thick. Joints and
                                                                                                                              this test.
                                                                    seams in the lining shall be made by
                                                                                                                                (b) [Reserved]
                                                                    fusing the material together or by
                                                                    other equally satisfactory means. The                     [29 FR 18972, Dec. 29, 1964. Redesignated at 32
                                                                    interior of the tank shall be free from                   FR 5606, Apr. 5, 1967, as amended by Amdt.
                                                                    scale, oxidation, moisture and all for-                   178–104, 59 FR 49135, Sept. 26, 1994]
                                                                    eign matter during the lining oper-
                                                                    ation.                                                    § 178.255–13     Repair of tanks.
                                                                       (b) [Reserved]                                           (a) Tanks failing to meet the test
                                                                                                                              may be repaired and retested, provided
                                                                    § 178.255–11 Tank mountings.                              that repairs are made in complete com-
dcolon on DSK2BSOYB1PROD with CFR




                                                                       (a) Tanks shall be designed and fab-                   pliance with the requirements of this
                                                                    ricated with mountings to provide a se-                   specification.
                                                                    cure base in transit. ‘‘Skids’’ or similar                  (b) [Reserved]

                                                                                                                         907



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                                                                    § 178.255–14                                                          49 CFR Ch. I (10–1–09 Edition)

                                                                    § 178.255–14 Marking.                                     § 178.273 Approval of Specification UN
                                                                                                                                    portable tanks.
                                                                       (a) In addition to markings required
                                                                    by Section VIII of the ASME Code                             (a) Application for approval. (1) An
                                                                    (IBR, see § 171.7 of this subchapter),                    owner or manufacturer of a portable
                                                                    every tank shall bear permanent marks                     tank shall apply for approval to a des-
                                                                    at least 1/8-inch high stamped into the                   ignated approval agency authorized to
                                                                    metal near the center of one of the                       approve the portable tank in accord-
                                                                    tank heads or stamped into a plate per-                   ance with the procedures in subpart E,
                                                                    manently attached to the tank by                          part 107 of this subchapter.
                                                                    means of brazing or welding or other                         (2) Each application for approval
                                                                    suitable means as follows:                                must contain the following informa-
                                                                                                                              tion:
                                                                    Manufacturer’s name lllllll Serial                           (i) Two complete copies of all engi-
                                                                     No.    llllllllllllllllllll
                                                                                                                              neering drawings, calculations, and
                                                                    DOT specification llllllllllllll
                                                                    Nominal capacity lllllll (gallons)                        test data necessary to ensure that the
                                                                    Tare weight lllllll (pounds)                              design meets the relevant specifica-
                                                                    Date of manufacture llllllllllll                          tion.
                                                                                                                                 (ii) The manufacturer’s serial number
                                                                      (b) [Reserved]                                          that will be assigned to each portable
                                                                    [29 FR 18972, Dec. 29, 1964. Redesignated at 32           tank.
                                                                    FR 5606, Apr. 5, 1967, and amended by Amdt.                  (iii) A statement as to whether the
                                                                    178–67, 46 FR 49906, Oct. 8, 1981; 68 FR 75750,           design type has been examined by any
                                                                    Dec. 31, 2003]                                            approval agency previously and judged
                                                                                                                              unacceptable. Affirmative statements
                                                                    § 178.255–15 Report.
                                                                                                                              must be documented with the name of
                                                                       (a) A copy of the manufacturer’s data                  the approval agency, reason for non-
                                                                    report required by Section VIII of the                    acceptance, and the nature of modifica-
                                                                    ASME Code (IBR, see § 171.7 of this sub-                  tions made to the design type.
                                                                    chapter) under which the tank is fab-                        (b) Action by approval agency. The ap-
                                                                    ricated must be furnished to the owner                    proval agency must perform the fol-
                                                                    for each new tank.                                        lowing activities:
                                                                              Place ———————————————                              (1) Review the application for ap-
                                                                              Date ————————————————                           proval to determine whether it is com-
                                                                          Portable tank                                       plete and conforms with the require-
                                                                    Manufactured for lllllll Company                          ments of paragraph (a) of this section.
                                                                    Location     llllllllllllllllll                           If an application is incomplete, it will
                                                                    Manufactured by lllllll Company                           be returned to the applicant with an
                                                                    Location     llllllllllllllllll
                                                                    Consigned to lllllllll Company
                                                                                                                              explanation as to why the application
                                                                    Location     llllllllllllllllll                           is incomplete.
                                                                    Size lll feet outside diameter by lll                        (2) Review all drawings and calcula-
                                                                      long.                                                   tions to ensure that the design is in
                                                                    Marks on tank as prescribed by § 178.255–14 of            compliance with all requirements of
                                                                      this specification are as follows:                      the relevant specification. If the appli-
                                                                    Manufacturer’s name llllllllllll                          cation is approved, one set of the ap-
                                                                    Serial number llllllllllllllll                            proved