ISO/IEC 80079-49:2024

Explosive atmospheres - Part 49: Flame arresters - Performance requirements, test methods and limits for use

ISO/IEC 80079-49:2024 specifies the requirements for flame arresters that prevent flame transmission when explosive gas-air or vapour-air mixtures are present. It establishes uniform principles for the classification, basic construction and information for use, including the marking of flame arresters, and specifies test methods to verify the safety requirements and determine safe limits of use.
This document is applicable to pressures ranging from 80 kPa to 160 kPa and temperatures ranging from -20 °C to +200 °C.
This document does not apply to the following:
- external safety-related measurement and control equipment that might be required to keep the operational conditions within the established safe limits;
- flame arresters used for explosive mixtures of vapours and gases, which tend to self-decompose (for example, acetylene) or which are chemically unstable;
- flame arresters used for carbon disulfide, due to its special properties;
- flame arresters whose intended use is for mixtures other than gas-air or vapour-air mixtures (for example, higher oxygen-nitrogen ratio, chlorine as oxidant);
- flame arrester test procedures for reciprocating internal combustion engines;
- fast acting valves, extinguishing systems and other explosion isolating systems;
- Flame arresters used in gas detectors (those being covered for example, by IEC 60079‑29‑1 and IEC 62990‑1).
This edition cancels and replaces ISO 16852:2016, which has been technically revised. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to ISO 16852:2016:
a) adaptation of the relevant IEC TC 31 requirements on standards;
b) modification of the upper limit of the temperature range from 150 °C to 200 °C under the condition that T0 shall be not larger than 80 % of the auto ignition temperature of the gas-air-mixture;
c) change of the term "explosion group" to "equipment group" due to editorial requirements in IEC/TC 31;
d) clarification of the conditions and requirements for flame arresters whose intended operating conditions are outside the atmospheric conditions in 7.3.4 and 7.3.5;
e) clarification of the requirements on the information for use in Clause 12 f) concerning the burn time;
f) addition of a permission to the construction requirements both in 7.1 and 14.1 to substitute visual inspection by performing a flow test;
g) addition of a flow chart for the evaluation of test results as Annex D

Arrête-flammes - Exigences de performance, méthodes d'essai et limites d'utilisation

General Information

• Status: Published
• Publication Date: 02-May-2024
• ICS: 13.220.10 - Fire-fighting
• Technical Committee: SC 31M - Non-electrical equipment and protective systems for explosive atmospheres
• Current Stage: PPUB - Publication issued
• Start Date: 03-May-2024
• Completion Date: 03-May-2024

Standards Content (Sample)

ISO/IEC 80079-49
Edition 1.0 2024-05
INTERNATIONAL
STANDARD
Explosive atmospheres –
Part 49: Flame arresters – Performance requirements, test methods and limits
for use
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ISO/IEC 80079-49
Edition 1.0 2024-05
INTERNATIONAL
STANDARD
Explosive atmospheres –
Part 49: Flame arresters – Performance requirements, test methods and limits

for use
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.220.10 ISBN 978-2-8322-8716-3

– 2 – ISO/IEC 80079-49:2024 © ISO/IEC 2024
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 9
3 Terms and definitions . 9
4 Abbreviated terms and symbols . 13
5 Hazards and flame arrester classifications . 14
5.1 Flame transmission classification: deflagration, stable and unstable
detonation . 14
5.2 Flame transmission classification: stabilized burning . 15
5.3 Index of tests . 15
6 General requirements . 16
6.1 Measuring instruments . 16
6.2 Flow measurement (air) . 17
6.3 Flame transmission test . 17
6.3.1 General . 17
6.3.2 Test mixtures . 17
7 Specific requirements for static flame arresters . 19
7.1 Construction requirements for prototype arresters . 19
7.2 Design series . 19
7.3 Flame transmission tests . 20
7.3.1 General . 20
7.3.2 Deflagration test . 21
7.3.3 Tests for detonation flame arresters . 24
7.3.4 Short time burning test . 30
7.3.5 Endurance burning test . 33
8 Specific requirements for liquid product detonation flame arresters . 34
8.1 Liquid seals . 34
8.2 Foot valves . 35
8.3 Flame transmission test . 36
9 Specific requirements for dynamic flame arresters (high velocity vent valves) . 37
9.1 General . 37
9.2 Flame transmission tests . 37
9.2.1 Low flow flame transmission test . 37
9.2.2 Flame transmission test by opening and closing . 39
9.2.3 Deflagration test . 40
9.2.4 Endurance burning test . 40
10 Specific requirements for hydraulic flame arresters . 41
10.1 Equipment . 41
10.2 Flame transmission tests . 41
10.2.1 General . 41
10.2.2 Short time burning test . 41
10.2.3 Deflagration test . 41
10.2.4 Detonation test . 42
11 Test of flame arresters installed on or within gas conveying equipment . 44
11.1 General . 44

11.2 Flame transmission tests . 44
11.2.1 General . 44
11.2.2 Test procedure for gas conveying equipment with inlet pressure
> 600 hPa . 46
11.2.3 Test procedure for gas conveying equipment with inlet pressure

≤ 600 hPa . 47
12 Instructions . 47
13 Marking . 48
13.1 Location . 48
13.2 Flame arrester housing . 49
13.2.1 General information . 49
13.2.2 Warning markings . 49
13.2.3 Examples of marking . 50
13.3 Flame arrester element . 51
14 Manufacturing and production . 51
14.1 Construction . 51
14.2 Housing . 51
14.3 Joints . 51
14.4 Pressure test . 51
14.5 Leak test . 52
Annex A (normative) Flow measurement . 53
A.1 General . 53
A.2 In-line flame arresters . 54
A.3 End-of-line flame arrester . 54
A.3.1 General . 54
A.3.2 Special flow measurement for dynamic flame arresters . 55
A.4 Undamped oscillation tests of dynamic flame arrester (High velocity vent

valves) . 56
Annex B (informative) Information for selecting flame arresters . 58
Annex C (informative) Recommended practice . 59
Annex D (informative) Evaluation of test results . 60
Annex E (normative) Application . 62
E.1 General . 62
E.2 Limits for use for static flame arresters . 63
E.2.1 In-line flame arrester . 63
E.2.2 Pre-volume flame arrester . 63
E.2.3 Detonation flame arrester . 63
E.2.4 Short time burn flame arrester . 63
E.3 Limits for use for liquid detonation flame arresters . 64
E.4 Limits for use for dynamic flame arresters (high velocity vent valves) . 64
E.5 Limits for use for hydraulic flame arresters . 64
Annex F (informative) Significant changes between this document and EN ISO
16852:2016 . 67
Bibliography . 69

Figure 1 – Test apparatus for end-of-line flame arrester for deflagration test . 21
Figure 2 – Test apparatus for in-line flame arrester for deflagration test . 22
Figure 3 – Test apparatus for pre-volume flame arrester for deflagration test . 24

– 4 – ISO/IEC 80079-49:2024 © ISO/IEC 2024
Figure 4 – Test apparatus for detonation flame arrester for detonation without
restriction. 26
Figure 5 – Test apparatus for detonation flame arrester for detonation with restriction . 28
Figure 6 – Test apparatus for short time burning test .
...