Anhydrous Ammonia TruckNurse Tank Riser Area Pull-Away Protection

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					 Pesticide and Fertilizer Management Division, Ph: 651-201-6275, Fx: 651-201-6117                                          FACT SHEET


Anhydrous Ammonia Truck/Nurse Tank Riser Area Pull-Away
Protection - Construction and Design Specification Requirements
TRUCK AND RISER FLOW PROTECTION                                             EXCEPTION: Because of the difficulty of employing sufficient
                                                                            bulkhead protection, riser excess flow valves are an exception.
DEVICES AND FUNCTION OF BULKHEADS
                                                                            In such cases automatically operating emergency shutoff
Backflow check, excess flow, and emergency shutoff                            valves protected by a bulkhead or shear/weakness fittings must
valves provide flow control protection (FCP) in the event                    supplement the riser excess flow valves.
of a hose rupture or pull away incident. In the truck unload
area, a backflow check valve is required for each liquid
                                                                            DESIGN CONSIDERATIONS
line outlet and a properly sized excess flow valve for each
                                                                            To afford adequate protection of system piping and FCP
vapor line outlet. Each liquid and vapor riser line outlet
                                                                            devices, the bulkhead must remain fully intact during a
(nurse tank loading) must be equipped with a properly
                                                                            pull- away incident. Depending on the direction of the
sized excess flow valve.
                                                                            pull-away, a truck unload area bulkhead must withstand a
                                                                            pull of approximately 5,000 to 10,000 pounds in contrast to
FCP devices must be installed in the facility piping so
                                                                            2,000 to 3,000 pounds for a riser area.
that any break will occur on the side of the hose or swivel
connection. This is where bulkhead pull-away protection
                                                                            Another consideration in the design of a bulkhead is the
for the truck unloading and riser areas come into play. A
                                                                            reduction factor. The reduction factor takes into account
bulkhead is defined as the entire above and below ground
                                                                            some of the construction, environmental, or material
structure that protects system piping and FCP devices. To
                                                                            specification that relates to the construction of a bulkhead,
afford adequate system protection, FCP devices, valving,
                                                                            and its ability to withstand a pull away. A reduction factor
piping, and other system appurtenances must be positioned
                                                                            of .66 is used in determining the material specifications
behind the bulkhead structure.
                                                                            listed in the Tables 1 through 4.




In accordance with the Americans with Disabilities Act, an alternative form of communication is available upon request.   anhydrous amm truck riser.indd
TTY: 1-800-627-3529. MDA is an equal opportunity employer and provider.                                                                           05/06
WHEN BULKHEAD PROTECTION MAY NOT                             TIME TABLE FOR COMPLIANCE
BE REQUIRED                                                  The installation of additional flow protection devices and
A bulkhead may not be required when the truck or riser       bulkhead protection must be completed within two years of
piping is equipped with suitable weakness or shear fittings   the effective date of Minnesota Rules, Part 1513.0200, or by
capable of breaking on the side of the hose or swivel        September 2, 1998.
connection. In the event of a pull away incident, the
weakness or shear fittings would only require sufficient       For more information, contact the Minnesota Department of
bracing, as specified by the manufacturer, to maintain the    Agriculture at 612/201-6275 or e-mail ekaiser@ mda.state.
condition of the system piping and other FCP devices.        mn.us