1 - AS/NZS 60079.2:2002 ELECTRICAL APPARATUS FOR EXPLOSIVE GAS ATMOSPHERES - PRESSURIZED ENCLOSURES 'p'
4 - PREFACE
5 - CONTENTS
9 - 1 Scope
9 - 2 Normative references
10 - 3 Terms and definitions
10 - 3.1 alarm
10 - 3.2 containment system
10 - 3.3 dilution
11 - 3.4 dilution area
11 - 3.5 enclosure volume
11 - 3.6 flammable substance
11 - 3.7 hermetically sealed device
11 - 3.8 ignition-capable apparatus (ICA)
11 - 3.9 indicator
11 - 3.10 internal source of release
11 - 3.11 leakage compensation
11 - 3.12 overpressure
11 - 3.13 pressurization
11 - 3.14 pressurization system
12 - 3.15 pressurized enclosure
12 - 3.16 protective gas
12 - 3.17 protective gas supply
12 - 3.18 purging
12 - 3.19 routine test
12 - 3.20 static pressurization
12 - 3.21 type px pressurizing
12 - 3.22 type py pressurizing
12 - 3.23 type pz pressurizing
12 - 3.24 type test
13 - 4 Protection types
14 - 5 Constructional requirements for pressurized enclosures
14 - 5.1 Enclosure
15 - 5.2 Materials
15 - 5.3 Doors and covers
15 - 5.4 Mechanical strength
15 - 5.5 Apertures, partitions, compartments and internal components
16 - 5.6 Insulating materials
16 - 5.7 Sealing
16 - 5.8 Spark and particle barriers
17 - 6 Temperature limits
17 - 6.1 General
17 - 6.2 For type px or type py
17 - 6.3 For type pz
17 - 7 Safety provisions and safety devices (except for static pressurization)
20 - 8 Safety provisions and safety devices for static pressurization
21 - 9 Supply of protective gas
21 - 9.1 Type of gas
21 - 9.2 Temperature
21 - 10 Pressurized apparatus with an internal source of release
21 - 11 Release conditions
21 - 11.1 No release
22 - 11.2 Limited release of a gas or vapour
22 - 11.3 Limited release of a liquid
22 - 12 Design requirements for the containment system
22 - 12.1 General design requirements
23 - 12.2 Infallible containment system
23 - 12.3 Containment system with a limited release
23 - 13 Protective gas and pressurizing techniques
23 - 13.1 General
25 - 13.2 Pressurization with leakage compensation
25 - 13.2.1 No release
25 - 13.2.2 Limited release of a gas or liquid
25 - 13.3 Pressurization with dilution
25 - 13.3.1 No release
25 - 13.3.2 Limited release of a gas or vapour
25 - 13.3.3 Limited release of a liquid
25 - 14 Ignition-capable apparatus
26 - 15 Internal hot surfaces
26 - 16 Type verification and tests
26 - 16.1 Maximum overpressure test
26 - 16.2 Leakage test
27 - 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
27 - 16.3.1 Pressurized enclosure where the protective gas is air
27 - 16.3.2 Pressurized enclosure where the protective gas is inert
27 - 16.3.3 Pressurized enclosure where the protective gas may be either air or an inert gas with density equal to air ±10%
27 - 16.3.4 Filling procedure test for a pressurized enclosure protected by static pressurization
27 - 16.4 Purging and dilution tests for a pressurized enclosure with an internal source of release
27 - 16.4.1 Test gas
28 - 16.4.2 Pressurized enclosure where the flammable substance has less than 2% (V/V) oxygen and the protective gas is inert
28 - 16.4.3 Pressurized enclosure with pressurization by continuous flow, containment system with less than 21% (V/V) oxygen ...
29 - 16.4.4 Pressurized enclosure where the flammable substance is not a liquid, pressurization by continuous flow and the prote
29 - 16.5 Verification of minimum overpressure
29 - 16.6 Tests for an infallible containment system
30 - 16.6.1 Overpressure test
30 - 16.6.2 Infallibility test
30 - 16.7 Overpressure test for a containment system with a limited release
30 - 16.8 Verifying ability of the pressurized enclosure to limit internal pressure
30 - 17 Routine tests
30 - 17.1 Functional test
31 - 17.2 Leakage test
31 - 17.3 Tests for an infallible containment system
31 - 17.4 Test for a containment system with a limited release
31 - 18 Marking
33 - Annex A - Purging and dilution tests
33 - A.1 General
33 - A.2 Criteria for compliance where the protective gas is air
33 - A.3 Criteria for compliance where the protective gas is inert
34 - Annex B - Examples of functional sequence diagram
36 - Annex C - Examples of the changes in pressure in ducts and enclosures
41 - Annex D - Information to be provided to the user
41 - D.1 General
41 - D.2 Ducting of protective gas
42 - D.3 Power for protective gas supply
42 - D.4 Static pressurization
42 - D.5 Enclosures with a containment system
42 - D.6 Enclosure maximum overpressure
43 - Annex E - Classification of the type of release within enclosures
43 - E.1 General
43 - E.2 No normal release, no abnormal release
43 - E.3 No normal release, limited abnormal release
43 - E.4 Limited normal release
44 - Annex F - Examples for the use of the dilution area concept
46 - Annex G - Infallibility test for containment system
47 - Bibliography