UL 60079-2
Standard for Explosive atmospheres - Part 2: Equipment protection by pressurized enclosure 'p'

DETAILS
Edition Number:6SCC Approved:--
Edition Date:2017-06-02DOD Approved: --
Price Code:EANSI Approved: 2017-06-02
Type:uliec

  • SCOPE

    1 Scope

    1DV Modification of Clause 1 to replace with the following:

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

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

    This standard does not include 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 where the oxygen is in a proportion greater than 21 %.

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

    • pressurized enclosures used where “explosives” or pyrotechnics are present;

    • pressurized enclosures used where hybrid mixtures of gas/vapour and combustible dust are present;

    • pressurized enclosures used where pyrophoric substances such as explosives or propellants containing their own oxidizers are present

    • pressurized enclosures with an internal source of release of combustible dust.

    NOTE 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.

    Where references are made to other IEC 60079 standards, the reference requirements found in these standards apply as modified by any applicable U.S. National Differences.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • Table of Contents
    • UL Preface
    • Deviations
    • IEC Foreword
    • IEC Introduction
      • EXPLOSIVE ATMOSPHERES – Part 2: Equipment protection by pressurized enclosure "p"
        • 1 Scope
        • 2 Normative references
        • 3 Terms and definitions
        • 4 Protection levels
        • 5 Constructional requirements for pressurized enclosures
          • 5.1 Enclosure
          • 5.2 Materials
          • 5.3 Doors and covers
          • 5.4 Mechanical strength
          • 5.5 Group I and Group II Apertures, partitions, compartments and internal components
          • 5.6 Apertures for Static Pressurization
          • 5.7 Insulating materials for Group I equipment
          • 5.8 Sealing
          • 5.9 Spark and particle barriers
          • 5.10 Cells and batteries
        • 6 Temperature limits
          • 6.1 General
          • 6.2 For Level of Protection “pxb” or Level of Protection “pyb”
          • 6.3 For Level of Protection “pzc”
        • 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 Pressurization System evaluated as associated equipment
          • 7.5 Sequence diagram for Level of Protection “pxb”
          • 7.6 Ratings for safety devices
          • 7.7 Group I and Group II Purging automated for Level of Protection “pxb”
          • 7.8 Group I or Group II − Purging criteria
          • 7.9 Group III – Cleaning
          • 7.10 Requirements when a minimum flow rate required
          • 7.11 Safety devices to detect minimum overpressure
          • 7.12 Value of minimum overpressure
          • 7.13 Pressurizing multiple enclosures
          • 7.14 Safety devices on doors and covers
          • 7.15 Equipment that may remain energized
          • 7.16 Equipment permitted within Level of Protection “pyb”
        • 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 Group I and Group II Filling procedure
          • 8.5 Group III Filling Procedure
          • 8.6 Safety devices
          • 8.7 Equipment that may remain energized
          • 8.8 Overpressure
        • 9 Supply of protective gas
          • 9.1 Backup supply
          • 9.2 Independent supplies
          • 9.3 Type of gas
          • 9.4 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 when there is an internal source of release
          • 13.1 General
          • 13.2 Pressurization with leakage compensation
          • 13.3 Pressurization with dilution
        • 14 Ignition-capable equipment
        • 15 Internal hot surfaces
        • 16 Type verification and tests
          • 16.1 Determining the maximum overpressure rating
          • 16.2 Maximum overpressure test
          • 16.3 Leakage test
          • 16.4 Purging test for pressurized enclosures with no internal source of release and filling procedure test for static pressurization
          • 16.5 Purging and dilution tests for a pressurized enclosure with an internal source of release
          • 16.6 Verification of minimum overpressure
          • 16.7 Tests for an infallible containment system
          • 16.8 Overpressure test for a containment system with a limited release
        • 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 General
          • 18.2 Identifying as pressurized
          • 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) Internal Cells and Batteries for Level of Protection “pxb” and Level of Protection “pyb”
    • Annex H (normative)Internal Cells and Batteries for Level of Protection “pzc”
    • Bibliography