UL 60079-2
Explosive Atmospheres - Part 2: Equipment Protection by Pressurized Enclosure “p”

DETAILS
Edition Number:5SCC Approved:--
Edition Date:2010-08-27DOD Approved: --
Price Code:EANSI Approved: 2015-01-16
Type:ulisaiec

  • SCOPE

    1 Scope

    This part of IEC 60079 contains the specific requirements for the construction and testing of electrical apparatus with pressurized enclosures, of type of protection “p”, intended for use in explosive gas atmospheres. It specifies requirements for pressurized enclosures containing a limited release of a flammable substance.

    This standard supplements and modifies the general requirements of IEC 60079-0. Where a requirement of this standard conflicts with a requirement of IEC 60079-0, the requirements of this standard takes precedence.

    This standard does not contain the requirements for:

    • pressurized enclosures where the containment system may release

    a) air with an oxygen content greater than normal, or

    b) oxygen in combination with inert gas in a proportion greater than 21 %;

    • pressurized rooms or analyser houses; see IEC 60079-13 and IEC 60079-16.

    NOTE 1 Due to the safety factors incorporated in the type of protection, the uncertainty of measurement inherent in good quality, regularly calibrated measurement equipment is considered to have no significant detrimental effect and need not be taken into account when making the measurements necessary to verify compliance of the equipment with the requirements of this standard.

    NOTE 2 When the user acts in the role of the manufacturer, it is typically the user’s responsibility to ensure that all relevant parts of this standard are applied to the manufacturing and testing of the equipment.

    NOTE 3 Types of protection “px” and “py”provide Equipment Protection Levels (EPL) Mb or Gb. Type of protection “pz” provides Equipment Protection Level (EPL) Gc. For further information, see Annex h.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • UL Harmonized Standard Title Page
    • Table of Contents
    • Foreword
    • Deviations
    • IEC Foreword
    • Introduction
      • EXPLOSIVE ATMOSPHERES – Part 2: Equipment protection by pressurized enclosure "p"
        • 1 Scope
        • 2 Normative references
        • 3 Terms and definitions
        • 4 Protection types
        • 5 Constructional requirements for pressurized enclosures
          • 5.1 Enclosure
          • 5.2 Materials
          • 5.3 Doors and covers
          • 5.4 Mechanical strength
          • 5.5 Apertures, partitions, compartments and internal components
          • 5.6 Insulating materials
          • 5.7 Sealing
          • 5.8 Spark and particle barriers
          • 5.9 Internal batteries
        • 6 Temperature limits
          • 6.1 General
          • 6.2 For type px or type py
          • 6.3 For type pz
        • 7 Safety provisions and safety devices (except for static pressurization)
          • 7.1 Suitability of safety devices for hazardous area
          • 7.2 Integrity of safety devices
          • 7.3 Provider of safety devices
          • 7.4 Sequence diagram for type px
          • 7.5 Ratings for safety devices
          • 7.6 Purging automated for type px
          • 7.7 Purging criteria
          • 7.8 Requirements when a minimum flow rate required
          • 7.9 Safety devices to detect overpressure
          • 7.10 Value of overpressure
          • 7.11 Pressurizing multiple enclosures
          • 7.12 Safety devices on doors and covers
          • 7.13 Protection types that may remain energized
          • 7.14 Protection types permitted within type py
        • 8 Safety provisions and safety devices for static pressurization
          • 8.1 Suitability of safety devices for hazardous area
          • 8.2 Protective gas
          • 8.3 Internal sources of release
          • 8.4 Filling procedure
          • 8.5 Safety devices
          • 8.6 Protection types that may remain energized
          • 8.7 Overpressure
        • 9 Supply of protective gas
          • 9.1 Type of gas
          • 9.2 Temperature
        • 10 Pressurized equipment with an internal source of release
        • 11 Release conditions
          • 11.1 No release
          • 11.2 Limited release of a gas or vapour
          • 11.3 Limited release of a liquid
        • 12 Design requirements for the containment system
          • 12.1 General design requirements
          • 12.2 Infallible containment system
          • 12.3 Containment system with a limited release
        • 13 Protective gas and pressurizing techniques
          • 13.1 General
          • 13.2 Pressurization with leakage compensation
          • 13.3 Pressurization with dilution
        • 14 Ignition-capable apparatus
        • 15 Internal hot surfaces
        • 16 Type verification and tests
          • 16.1 Maximum overpressure test
          • 16.2 Leakage test
          • 16.3 Purging test for pressurized enclosures with no internal source of release (pressurization technique may be leakage compensation or continuous flow) and filling procedure test for static pressurization
          • 16.4 Purging and dilution tests for a pressurized enclosure with an internal source of release
          • 16.5 Verification of minimum overpressure
          • 16.6 Tests for an infallible containment system
          • 16.7 Overpressure test for a containment system with a limited release
          • 16.8 Verifying ability of the pressurized enclosure to limit internal pressure
        • 17 Routine tests
          • 17.1 Functional test
          • 17.2 Leakage test
          • 17.3 Tests for an infallible containment system
          • 17.4 Test for a containment system with a limited release
        • 18 Marking
          • 18.1 Identifying as pressurized
          • 18.2 Warnings
          • 18.3 Supplementary marking
          • 18.4 Internal source of release
          • 18.5 Static pressurization
          • 18.6 Pressurization systems
          • 18.7 Warnings required in other clauses
          • 18.8 Overpressure limited by user
          • 18.9 Inert gas
        • 19 Instructions
    • Annex A (normative) Purging and dilution tests
    • Annex B (informative) Examples of functional sequence diagram
    • Annex C (informative) Examples of the changes in pressure in ducts and enclosures
    • Annex D (informative) Information to be provided to the user
    • Annex E (normative) Classification of the type of release within enclosures
    • Annex F (informative) Examples for the use of the dilution area concept
    • Annex G (normative) Infallibility test for containment system
    • Annex H (informative) Introduction of an alternative risk assessment method encompassing “equipment protection levels” for Ex equipment
    • Bibliography