BS EN ISO 80079-36:2016 - Page 3

Explosive atmospheres. Non-electrical equipment for explosive atmospheres. Basic method and requirements | Status: Current

1 Scope This part of ISO/IEC 80079 specifies the basic method and requirements for design, construction, testing and marking of non-electrical Ex equipment, Ex Components, protective systems, devices and assemblies of these products that have their own potential ignition sources and are intended for use in explosive atmospheres. Hand tools and manually operated equipment without energy storage are excluded from the scope of this standard. This standard does not address the safety of static autonomous process equipment when it is not part of equipment referred to in this standard.

NOTE 1 Static autonomous process equipment includes items such as tanks, vessels, fixed pipework and hand operated valves which do not have their own source of energy that could create a potential ignition source during operation.

This standard does not specify requirements for safety, other than those directly related to the risk of ignition which may then lead to an explosion. The standard atmospheric conditions (relating to the explosion characteristics of the atmosphere) under which it may be assumed that equipment can be operated are:

• • temperature -20 °C to +60 °C;
• • pressure 80 kPa (0,8 bar) to 110 kPa (1,1 bar); and
• • air with normal oxygen content, typically 21 % v/v.

Such atmospheres can also exist inside the equipment. In addition, the external atmosphere can be drawn inside the equipment by natural breathing produced as a result of fluctuations in the equipment’s internal operating pressure, and/or temperature.

NOTE 2 Although the standard atmospheric conditions above give a temperature range for the atmosphere of - 20 °C to +60 °C, the normal ambient temperature range for the equipment is -20 °C to +40 °C, unless otherwise specified and marked. It is considered that -20 °C to +40 °C is appropriate for most equipment and that to manufacture all equipment to be suitable for a standard atmosphere upper ambient temperature of +60 °C would place unnecessary design constraints.

NOTE 3 The requirements of this standard can also be helpful for the design, construction, testing and marking of equipment intended for use in atmospheres outside the validity range stated above. In this case however, the ignition hazard assessment, ignition protection provided, additional testing (if necessary), manufacturer’s technical documentation and instructions to the user, clearly demonstrate and indicate the equipment’s suitability for the conditions it may encounter. It is also recognized that changes in temperature and pressure can have a significant influence on characteristics of the explosive atmosphere, such as ignitability.

This part of ISO/IEC 80079 specifies the requirements for the design and construction of equipment, intended for explosive atmospheres in conformity with all Equipment Protection Levels (EPLs) of Group I, II and III.

NOTE 4 It is not unusual for equipment designed and constructed in accordance with this standard for a particular EPL to be used in areas requiring an EPL with a higher level of safety by including the application of additional measures. Such measures include for example inerting, suppression, venting or containment or for example by dilution, drainage, monitoring and shut-down. Such measures are outside the scope of this standard.

This standard supplements and modifies the general requirements of IEC 60079‑0, as shown in Table 1. Where a requirement of this standard conflicts with a requirement of IEC 60079‑0, as far as applicable for non-electrical equipment, the requirement of this standard takes precedence. This standard is supplemented or modified by the following standards concerning specific types of protection:

• – ISO 80079‑37 , Explosive atmospheres – Part 37: Non-electrical equipment for explosive atmospheres – Non-electrical type of protection constructional safety "c", control of ignition source "b", liquid immersion "k"
• – IEC 60079‑1 , Explosive atmospheres – Part 1: Equipment protection by flameproof enclosures "d"
• – IEC 60079‑2 , Explosive atmospheres – Part 2: Equipment protection by pressurized enclosures "p"
• – IEC 60079‑31 , Explosive atmospheres – Part 31: Equipment dust ignition protection by enclosure "t"

The nature and ignition sources of non-electrical equipment shall be considered when applying types of protection "d", "p", or "t" on non-electrical equipment (see Annex G). Table 1 — Applicability of specific clauses of IEC 60079‑0 Clause of IEC 60079‑0 IEC 60079‑0 application to Ed 6.0 (2011) (Inf.) Clause / Sub-Clause Title (Normative) ISO 80079‑36 ISO 80079‑37 "c" "b" "k" 4 Equipment grouping Modified (see Clause 4) (*) (*) (*) 4.1 Group I Applies (*) (*) (*) 4.2 Group II Applies (*) (*) (*) 4.3 Group III Modified (see 4.4) (*) (*) (*) 4.4 Equipment for a particular explosive atmosphere Applies (*) (*) (*) 5 Temperatures Modified (see 6.2 and Table 2) (*) (*) (*) 5.1 Environmental influences Applies (*) (*) (*) 5.1.1 Ambient temperature Applies to be read as non- electrical equipment (*) (*) (*) 5.1.2 External source of heating or cooling Applies to be read as non- electrical equipment (*) (*) (*) 5.2 Service temperature Applies to be read as non- electrical equipment (*) (*) (*) 5.3.1 Determination of maximum surface temperature Modified (see 6.2.3) non-electrical (*) (*) (*) 5.3.2.1 Group I electrical equipment Modified (see 6.2.4) non-electrical (*) (*) (*) 5.3.2.2 Group II electrical equipment Modified (see 6.2.5) non-electrical (*) (*) (*) 5.3.2.3 Group III electrical equipment Modified (see 6.2.7) non-electrical (*) (*) (*) 5.3.3 Small component temperature for Group I and Group II electrical equipment Modified (see 6.2.6) non-electrical (*) (*) (*) 6. Requirements for all electrical equipment Applies to be read as non- electrical equipment (*) (*) (*) 6.1 General Applies to be read as non- electrical equipment (*) (*) (*) 6.2 Mechanical strength of equipment Applies (*) (*) (*) 6.3 Opening times Modified (see 7.3) (*) (*) (*) 6.4 Circulating currents in enclosures (e.g. of large electrical machines) Applies (*) (*) (*) 6.5 Gasket retention Applies (*) (*) (*) 6.6 Electromagnetic and ultrasonic energy radiating equipment Excluded - - - 7 Non-metallic enclosures and non- metallic parts of enclosures Applies (*) (*) (*) 7.1 General Applies (*) (*) (*) 7.1.1 Applicability Applies (*) (*) (*) 7.1.2 Specification of materials Applies (*) (*) (*) 7.2 Thermal endurance Applies (*) (*) (*) 7.3 Resistance to light Applies (*) (*) (*) 7.4 Electrostatic charges on external non-metallic materials Modified (see 6.7.4, 6.7.5 and 6.7.6) (*) (*) (*) 7.5 Accessible metal parts Applies (*) (*) (*) 8 Metallic enclosures and metallic parts of enclosures Modified (see 6.4.2.1 Footnote 1) and ref. to ISO 6507‑1 (*) (*) (*) 8.1 Material composition Modified (see 6.4.2.1 Footnote 1) and ref. to ISO 6507‑1 (*) (*) (*) 8.2 Group I Modified (see 6.4.2.1 Footnote 1) and ref. to ISO 6507‑1 (*) (*) (*) 8.3 Group II Modified (see 6.4.2.1 Footnote 1) and ref. to ISO 6507‑1 (*) (*) (*) 8.4 Group III Modified (see 6.4.2.1 Footnote 1) and ref. to ISO 6507‑1 (*) (*) (*) 9 Fasteners Excluded - - - 10 Interlocking devices Excluded - - - 11 Bushings Excluded - - - 12 Materials used for cementing Applies (see 7.6) (*) (*) (*) 13 Ex Components Applies (*) (*) (*) 14 Connection facilities and termination compartments Excluded - - - 15 Connection facilities for earthing or bonding conductors Excluded - - - 16 Entries into enclosures Excluded - - - 17 Supplementary requirements for rotating machines Excluded - - - 18 Supplementary requirements for switchgear Excluded - - - 19 Supplementary requirements for fuses Excluded - - - 20 Supplementary requirements for plugs, socket outlets and connectors Excluded - - - 21 Supplementary requirements for luminaires Excluded - - - 22 Supplementary requirements for caplights and handlights Excluded - - - 23 Equipment incorporating cells and batteries Excluded - - - 24 Documentation Modified (see 9) (*) (*) (*) 25 Compliance of prototype or sample with documents Applies (*) (*) (*) 26 Type Tests Modified (see 8) (*) (*) (*) 26.1 General Applies (*) (*) (*) 26.2 Test configuration Applies to be read as non- electrical equipment (*) (*) (*) 26.3 Tests in explosive test mixtures Applies (*) (*) (*) 26.4.1 Order of tests Excluded - - - 26.4.2 Resistance to impact Applies (see 8.3.1) (*) (*) (*) 26.4.3 Drop test Applies (see 8.3.2) (*) (*) (*) 26.4.4 Acceptance criteria Applies (see 8.3.3 (*) (*) (*) 26.4.5 Degree of protection (IP) by enclosure Applies (*) (*) (*) 26.5.1.1 General Applies (*) (*) (*) 26.5.1.2 Service temperature Applies (*) (*) (*) 26.5.1.3 Maximum surface temperature Modified (see 8.2) (*) (*) (*) 26.5.2 Thermal shock test Applies (*) (*) (*) 26.5.3 Small component ignition test (Group I and Group II) Excluded - - - 26.6 Torque test for bushings Excluded - - - 26.7 Non-metallic enclosures or non- metallic parts of enclosures Applies (*) (*) (*) 26.8 Thermal endurance to heat Applies (see 8.4.4) (*) (*) (*) 26.9 Thermal endurance to cold Applies (see 8.4.5) (*) (*) (*) 26.10 Resistance to light Applies (*) (*) (*) 26.11 Resistance to chemical agents for Group I electrical equipment Applies (see 8.4.6) (*) (*) (*) 26.12 Earth continuity Excluded - - - 26.13 Surface resistance test of parts of enclosures of non-metallic materials Applies (*) (*) (*) 26.14 Measurement of capacitance Excluded - - - 26.15 Verification of ratings of ventilating fans Excluded - - - 26.16 Alternative qualification of elastomeric sealing O-rings Applies (*) (*) (*) 27 Routine tests Applies (*) (*) (*) 28 Manufacturer's responsibility Modified (see 9.1) (*) (*) (*) 29 Marking Modified (see 11) (*) (*) (*) 30 Instructions Modified (see 10) (*) (*) (*) 30.1 General Applies (*) (*) (*) 30.2 Cells and batteries Excluded - - - 30.3 Electrical machines Excluded - - - 30.4 Ventilating fans Excluded - - - (*) This requirement concerns also equipment protected by types of protection "c", "b" and "k". Applies – This requirement of IEC 60079‑0is applied without change Excluded – This requirement of IEC 60079‑0 does not apply. Modified – This requirement of IEC 60079‑0 is modified as detailed in this standard. The applicable requirements of IEC 60079‑0 are identified by the clause title which is normative. This document was written referring to the specific requirements of IEC 60079‑0 Ed. 6.0:2011, The clause numbers for the 6th edition are shown for information only. This is to enable the General Requirements IEC 60079‑0 Ed. 5.0:2007 to be used where necessary with this part of ISO 80079. Where there were no requirements for the 5th edition or where there is a conflict between requirements, the 6th edition requirements should be considered.