CERTIFICATION OF EQUIPMENT FOR USE IN POTENTIALLY EXPLOSIVE by jtl17221

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									 CERTIFICATION OF
 EQUIPMENT FOR USE IN
 POTENTIALLY EXPLOSIVE
 ATMOSPHERES


What do I Really Have to Do ?



                                PHOENIX
                                LOSS PREVENTION
    UK’S IMPLEMENTATION OF
             ATEX
   1999/92/EC – ATEX 137 – Implemented as
    The Dangerous Substances and Explosive
    Atmospheres Regulations 2002 (DSEAR) –
    Social Directive

   94/9/EC – ATEX 100 – Implemented as the
    Equipment and Protective Systems for Use in
    Potentially Explosive Atmospheres
    Regulations 1996 (EPS) – Trade Directive
                                          PHOENIX
                                          LOSS PREVENTION
     DUTIES UNDER DSEAR
   Conduct Risk Assessment relating to
    Explosive Atmospheres and their potential
    threat to people – hazards from flammable
    gases and vapours and combustible dusts

   Conduct Area Classification – define
    locations of Hazardous Areas in the
    workplace

   Employ suitable Safety Management systems
    to ensure that an adequate level of explosion
    safety is maintained
                                            PHOENIX
                                            LOSS PREVENTION
    SUPPLIER RESPONSIBILITIES
           UNDER EPS
   Assess risks associated with equipment to
    demonstrate it is safe for use

   Ensure that equipment supplied for use in areas
    defined as hazardous by the customer is
    suitably certified for the type of hazardous area
    in which it will be installed

   Must consider all potential ignition sources – e.g.
    flames, sparks, static, etc – not just electrical
    ignition sources
                                                PHOENIX
                                                LOSS PREVENTION
Supplier’s Responsibilities (cont)

   Ensure equipment is suitably labelled

   Maintain a technical file and quality
    records re production

   Provide instructions for Installation,
    Maintenance, Inspection and Use

                                             PHOENIX
                                             LOSS PREVENTION
Operator’s Responsibilities when
           Ordering
 – Tell the supplier what classification of hazardous
   area the equipment will be installed in

 – Tell the supplier if the equipment is to be
   connected to other equipment which may contain
   an explosive atmosphere

 – Tell the supplier what material the equipment will
   handle (if it is processing material) and provide
   information on material properties


                                                  PHOENIX
                                                  LOSS PREVENTION
           Information on Material
                 Properties
   As a minimum
    –   Whether the material can support an explosion (gas or dust)
    –   Physical characteristics
    –   Gas – autoignition temperature
    –   Dust - Layer Ignition Temperature & Minimum Cloud Ignition
        Temperature
   Other data which the supplier may need to request
    (depending on how equipment is to be protected)
    – Minimum Ignition Energy
    – Explosion Indices




                                                             PHOENIX
                                                            LOSS PREVENTION
           CUSTOMER MUST PROVIDE
         INFORMATION ON HAZARDOUS
                   AREAS

         WHAT IS A HAZARDOUS AREA?

   “A place in which an explosive atmosphere may occur in sufficient
    quantities to require special precautions to protect the health and
    safety of the workers concerned is deemed to be hazardous”

   “A place in which an explosive atmosphere is not expected to occur
    in such quantities to require special precautions is deemed to be
    non-hazardous within the meaning of these Regulations”



                                                                 PHOENIX
                                                                 LOSS PREVENTION
        HAZARDOUS AREA
    DEFINITIONS UNDER DSEAR
   Zone 0 (20): A place in which an explosive atmosphere consisting of
    a mixture with air of flammable substances in the form of gas,
    vapour or mist (or dust) is present continuously or for long periods or
    frequently.

   Zone 1 (21): A place in which an explosive atmosphere consisting of
    a mixture with air of flammable substances in the form of gas,
    vapour or mist (or dust) is likely to occur in normal operation
    occasionally.

   Zone 2 (22): A place in which an explosive atmosphere consisting of
    a mixture with air of flammable substances in the form of gas,
    vapour or mist (or dust) is not likely to occur in normal operation but,
    if it does occur, will persist for a short period only.


                                                                  PHOENIX
                                                                  LOSS PREVENTION
      Problems re Classification of
           Hazardous Areas
   Customers tend to be conservative and “over-classify”
    hazardous areas

   Customers may not have classified hazardous areas

   Zone 0/20 & 1/21 require that explosive concentrations are
    present in normal operation
    (e.g. >20,000ppm or 50g/m3)

   Majority of workplaces will be no worse than Zone 2/22 (and
    may be safe)

   Need to include the new equipment in the evaluation of
    workplace hazardous areas – ideally operator would consult
    with supplier

   Be prepared to challenge the customer‟s area classification

                                                             PHOENIX
                                                             LOSS PREVENTION
Classification of Gas Hazardous
              Areas
   Tendency is to be too conservative (e.g.
    extent of flammable atmosphere above
    flammable liquids will generally be small)

   Historical “Flameproof” areas might not be
    zone 1

   Take credit for ventilation

                                                 PHOENIX
                                                 LOSS PREVENTION
               TABLE 3.1 : INFLUENCE OF VENTILATION ON TYPE OF ZONE

                                                           Ventilation

                                                             Degree
Grade of
release                          High                                      Medium                  Low

                                                           Availability

                Good              Fair             Poor        Good          Fair      Poor     Good, fair
                                                                                                 or poor
Continuous   (Zone 0 NE) (Zone 0 NE) (Zone 0 NE) Zone 0                   Zone 0    Zone 0     Zone 0
                                                                          +         +
             Non-             Zone 2 1)        Zone 1 1)                  Zone 2    Zone 1
                         1)
             hazardous

Primary      (Zone 1 NE) (Zone 1 NE) (Zone 1 NE) Zone 1                   Zone 1    Zone 1     Zone 1
                                                                          +         +          or
             Non-             Zone 2 1)        Zone 2 1)                  Zone 2    Zone 2     Zone 0 3)
                         1)
             hazardous
          2)
Secondary 2) (Zone 2 NE) (Zone 2 NE) Zone 2                 Zone 2        Zone 2    Zone 2     Zone 1
                                                                                               and even
             Non-             Non-                                                             Zone 0 3)
                         1)               1)
             hazardous        hazardous
       1)
               Zone 0 NE, 1 NE or 2 NE indicates a theoretical zone which would be of negligible extent
               under normal conditions.
       2)
               The zone 2 area created by a secondary grade of release may exceed that attributable to a
               primary or continuous grade of release; in which case, the greater distance should be taken.
       3)
               Will be zone 0 if the ventilation is so weak and the release is such that in practice an
               explosive atmosphere exists virtually continuously (i.e. approaching a “no ventilation”
               condition).

       NOTE - “+ ” signifies “surrounded by”.
               EXPLOSIVE DUST
                ATMOSPHERE




A cloud of 40 g/m3 of coal dust
in air is so dense that a glowing
25W light bulb can hardly be
seen through a dust cloud of
2m thickness

                                    PHOENIX
                                    LOSS PREVENTION
      CLASSIFICATION OF
         EQUIPMENT

You have agreed with your customer what
 the hazardous areas are – what do you
now have to do to classify your equipment



                                      PHOENIX
                                     LOSS PREVENTION
     Certification of Equipment for
       Use in Hazardous Area
1.   Equipment which does not handle hazardous
     material – only need to address the potential for the
     equipment to ignite a surrounding explosive
     atmosphere

2.   Equipment which handles hazardous material –
     have to address control of explosion risks inherent
     to the equipment, the potential to ignite a
     surrounding explosive atmosphere, and the
     potential to ignite an explosive atmosphere in
     connected equipment

                                                    PHOENIX
                                                    LOSS PREVENTION
Equipment Classification to EPS
   Category 3 – equipment which does not represent
    an ignition source in normal operation – suitable for
    use in zone 2 (22) area

   Category 2 – equipment which does not create an
    ignition source in normal operation, or in the event of
    a foreseeable malfunction – suitable for use in zone 1
    (21) and 2 (22) areas

   Category 1 – equipment which does not create an
    ignition source even in the event of a rare malfunction
    – suitable for use in zone 0 (20, 1 (21) and 2 (22)
    areas
                                                     PHOENIX
                                                     LOSS PREVENTION
           Authority to Classify
   Category 3 – self certification by supplier

   Category 2, non-electrical ignition sources – self
    certification by supplier (technical file to be sent to a
    Notified Body)

   Category 2, electrical ignition sources (or internal
    combustion engines) – certification by Notified Body

   Category 1 – certification by Notified Body

   Have to be clear if the equipment is certified for
    Gases (G) or Dusts (D) or both (G/D)

                                                         PHOENIX
                                                         LOSS PREVENTION
Equipment from Outside the EC
   For equipment manufactured in the EC the
    supplier is responsible for the certification

   When equipment is imported from outside the
    EC it must still be certified, and either the EC
    agent (if there is one), or the EC customer
    has to take on the responsibilities of the
    supplier


                                               PHOENIX
                                               LOSS PREVENTION
     Certification of Equipment
   Have to consider the Machinery Directive as well as
    EPS

   Do risk assessment for Machinery Directive first, then
    move on to EPS

   Machinery Directive requires a demonstration that the
    equipment is safe for intended use – requires
    consideration of inherent explosion hazards – may
    determine that equipment requires explosion
    protection

   Having completed the Machinery Directive risk
    assessment conduct an Ignition Hazard Assessment
    for EPS
                                                    PHOENIX
                                                    LOSS PREVENTION
Explosion Protection Devices
   Equipment Intended to provide protection against
    explosion affects, or to prevent explosion propagation
    from an item of equipment to another are “explosion
    protection devices” and must be Certified under EPS
    (by a notified body)

   Examples are :
    –   Relief panels
    –   Suppression Systems
    –   Explosion Barrier Valves
    –   etc


                                                    PHOENIX
                                                    LOSS PREVENTION
Let’s look at how to classify the
 two types of equipment (that
    which does not handle a
 flammable material and that
          which does)




                              PHOENIX
                              LOSS PREVENTION
      Equipment which does not
      handle Hazardous Material
   Machinery Directive assessment will
    concentrate on basic health and safety
    requirements (e.g. guarding) and will not
    touch on EPS matters

   Ignition Hazard Assessment required to
    categorise equipment depending on its ability
    to ignite a surrounding explosive atmosphere


                                                PHOENIX
                                                LOSS PREVENTION
    Ignition Hazard Assessment
   Systematically review the operation of the equipment to identify
    conditions when ignition sources could arise

   Consider all potential sources of ignition (e.g. electrical &
    mechanical sparks, friction / hot surfaces, static)

   Consider normal (intended) operation first

   Identify foreseeable malfunctions and decide whether these
    could create ignition sources (considering ignition of a
    surrounding explosive atmosphere)

   Identify rare malfunctions (e.g. two simultaneous malfunctions)
    and decide whether these could create ignition sources

   BS EN 13463 provides a methodology


                                                                PHOENIX
                                                                LOSS PREVENTION
     Possible Outcomes of Ignition
         Hazard Assessment
1.   Equipment provides an ignition source in normal
     operation – can‟t certify under EPS (need to look at
     measures to remove the ignition source)
2.   Equipment provides an ignition source as a result
     of a foreseeable malfunction – self certify as
     Category 3
3.   Equipment provides an ignition source as a result
     of a rare malfunction – self certify as Category 2 (if
     no electrical ignition sources). If machine has some
     electrical components then invite Notified Body to
     certify, or use pre-certified category 1 or 2 electrical
     components in the assembly - lodge technical file
     with Notified Body
4.   Equipment does not provide an ignition source in
     the event of a rare malfunction – invite Notified
     Body to certify as category 1
                                                       PHOENIX
                                                       LOSS PREVENTION
       Further Considerations
   Creation of sparks or hot surfaces inside
    equipment may ignite a surrounding
    explosive atmosphere if there is no isolation

   Have to consider how the equipment might
    be used (abused) by the customer – may
    need some additional controls to prevent
    inadvertent incorrect use – or some warnings
    in instructions provided with the machine
                                              PHOENIX
                                              LOSS PREVENTION
PHOENIX
LOSS PREVENTION
          Equipment Handling a
           Hazardous Material
   Conduct Machinery Directive Risk Assessment
    – Identify causes of explosive atmosphere within equipment
    – Look for possible sources of ignition of any such
      atmospheres
    – Determine whether ignition sources can be adequately
      controlled
    – Decide whether explosion protection is needed (will depend
      on overall risk – frequency and consequences)
    – Define explosion protection controls


   Complete Ignition Hazard Assessment in relation to
    an explosive atmosphere surrounding the equipment,
    and any explosive atmospheres in items which will be
    connected to the equipment, taking into account
    controls defined by the Machinery assessment
                                                          PHOENIX
                                                          LOSS PREVENTION
Implications of Internal Ignitions
   Ignition of an explosive atmosphere within an item of
    equipment may create an ignition source to an
    explosive atmosphere surrounding the equipment, if
    there is no isolation

   e.g. assessment of components on the outside of the
    equipment might allow Category 2, but internal
    ignition from a foreseeable malfunction would reduce
    this to Category 3 if flame can propagate from inside
    to outside

   Isolation devices will be “explosion protection
    devices” under EPS and will have to be certified by a
    notified body


                                                    PHOENIX
                                                    LOSS PREVENTION
    Transfer of Ignition Sources to
       Connected Equipment
   “Internal” classification of machine (i.e.
    likelihood of ignition sources to up- and down-
    stream equipment) may be different to
    external classification

   If internal classification is not compatible with
    hazardous area classification for connected
    items will have to advise the customer that
    the connected items require explosion
    protection
                                                PHOENIX
                                                LOSS PREVENTION
           Key Problems with the
                Regulations
   Many suppliers are not confident enough to self
    certify equipment

   Operators tend to overstate the hazardous areas

   Difficult to take into account the different ignition and
    combustion properties of different materials

   Assistance from Notified bodies can be expensive



                                                        PHOENIX
                                                        LOSS PREVENTION
         EXAMPLE – Hammer Mill
   Zone 22 workplace, Category
    3D mill required as a
    minimum
   But internal explosive
    atmosphere in normal
    operation identified by the
    Machinery Risk Assessment,
    and possible ignition source
    in the event of a malfunction
   Large volume grist hopper –
    consequences of explosion
    could be severe
   Explosion protection required
   EPS certified explosion
    barriers required to prevent
    explosion protection to
    connected equipment (which
    might also contain explosive
    atmospheres)                    PHOENIX
                                    LOSS PREVENTION
   So if my risk assessment
determines that my equipment
 requires explosion protection
        what can I do ?



                           PHOENIX
                          LOSS PREVENTION
          Explosion Protection
 Explosion Containment
  – design plant for maximum explosion pressure
 Explosion Suppression
  – install extinguishing system
 Explosion Venting
  – provide weak panel to relieve pressure
 Explosion Isolation
    – prevent explosion propagation
   In all cases would have to use Certified Devices
    approved by a Notified Body
                                                  PHOENIX
                                                  LOSS PREVENTION
                                   MYTH
     Existing equipment must be replaced
        by ATEX approved equipment
   Equipment on the market before 1st July 2003
    exempt from EPS (ATEX 100)
    – i.e. already installed, second hand or in stores
   Equipment must be safe for use in hazardous
    areas
    – e.g. old “Ex” rated electrical equipment in
      gas/liquid zones & suitable „IP‟ rating for dust
      zones – suitable surface temperatures in both
      cases
                                                    PHOENIX
                                                    LOSS PREVENTION
                               MYTH
      Existing protective systems must be
      replaced by ATEX certified systems
   Protective systems on
    the market before 1st
    July 2003 are exempt
    from EPS
    – Aluminium panels
      secured by nylon bolts
    – Explosion Doors with
      Brixon Latches
   OK to retain so long as
    they provide effective
    protection
                                      PHOENIX
                                      LOSS PREVENTION
              OTHER AREAS OF
                CONFUSION
   Maintenance of Certified Equipment
    – Under EPS Suppliers must provide essential information for
      operation and maintenance – qualified technicians should be
      able to perform all necessary maintenance
   Refurbishing Old Equipment
    – Can legitimately refurbish equipment back to its original state
      without having to certify it – only have to certify if
      functionality is changed
   Use of Plastic in Hazardous areas
    – No restriction in zone 2/22 areas




                                                               PHOENIX
                                                               LOSS PREVENTION
                 SUMMARY
 Operator is responsible for Area Classification and
  must tell the Supplier what classification of hazardous
  area equipment will be required to operate in, and
  whether it will be connected to hazardous areas in
  other equipment
 Be prepared to challenge the Customer‟s area
  classification
 Most equipment will be going into zone 2 (22) areas
  at worst, so can self certify
 Conduct Machinery Assessment first to define any
  explosion controls, then conduct Ignition Hazard
  Assessment
 Suppliers should provide instructions for safe
  operation which should cover maintenance as well
                                                   PHOENIX
                                                   LOSS PREVENTION

								
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