oSIST prEN ISO/IEC 80079-49:2022

SLOVENSKI STANDARD
oSIST prEN ISO/IEC 80079-49:2022
01-november-2022
Eksplozivne atmosfere - 49. del: Plamenske zapore - Zahtevane lastnosti,
preskusne metode in omejitve uporabe (ISO/IEC/DIS 80079-49:2022)
Explosive atmospheres - Part 49: Flame arresters - Performance requirements, test
methods and limits for use (ISO/IEC/DIS 80079-49:2022)
Explosive Atmosphären - Teil 49: Flammendurchschlagsicherungen -
Leistungsanforderungen, Prüfverfahren und Einsatzgrenzen (ISO/IEC/DIS 80079-
49:2022)
Atmosphères explosives - Partie 49: Titre manque (ISO/IEC/DIS 80079-49:2022)
Ta slovenski standard je istoveten z: prEN ISO/IEC 80079-49
ICS:
13.220.20 Požarna zaščita Fire protection
13.230 Varstvo pred eksplozijo Explosion protection
29.260.20 Električni aparati za Electrical apparatus for
eksplozivna ozračja explosive atmospheres
oSIST prEN ISO/IEC 80079-49:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO/IEC 80079-49:2022

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oSIST prEN ISO/IEC 80079-49:2022
DRAFT INTERNATIONAL STANDARD
ISO/IEC DIS 80079-49
ISO/TMBG Secretariat: ISO
Voting begins on: Voting terminates on:
2022-09-02 2022-11-25
Explosive atmospheres —
Part 49:
Flame arresters — Performance requirements, test
methods and limits for use
ICS: 13.220.20
Member bodies are requested to consult relevant national interests in IEC/SC
31M before casting their ballot to the e-Balloting application.
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
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NATIONAL REGULATIONS.
ISO/IEC DIS 80079-49:2022(E)
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PROVIDE SUPPORTING DOCUMENTATION. © ISO/IEC 2022

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oSIST prEN ISO/IEC 80079-49:2022
ISO/IEC DIS 80079-49:2022(E)
DRAFT INTERNATIONAL STANDARD
ISO/IEC DIS 80079-49
ISO/TMBG Secretariat: ISO
Voting begins on: Voting terminates on:
2022-09-02 2022-11-25
Explosive atmospheres —
Part 49:
Flame arresters — Performance requirements, test
methods and limits for use
ICS: 13.220.20
Member bodies are requested to consult relevant national interests in IEC/SC
31M before casting their ballot to the e-Balloting application.
This document is circulated as received from the committee secretariat.
COPYRIGHT PROTECTED DOCUMENT
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© ISO/IEC 2022
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NATIONAL REGULATIONS.
Website: www.iso.org ISO/IEC DIS 80079-49:2022(E)
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ii
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oSIST prEN ISO/IEC 80079-49:2022
31M/173/CDV – 2 – ISO/IEC 80079-49 © IEC:2021
1 CONTENTS
2
3 FOREWORD . 5
4 INTRODUCTION . 7
5 1 Scope . 8
6 2 Normative references . 8
7 3 Terms and definitions . 9
8 4 Abbreviated terms and symbols . 12
9 5 Hazards and flame arrester classifications . 14
10 5.1 Flame transmission classification: deflagration, stable and unstable
11 detonation . 14
12 5.2 Flame transmission classification: stabilized burning. 14
13 5.3 Index of tests . 14
14 6 General requirements . 15
15 6.1 Measuring instruments . 15
16 6.2 Flow measurement (air) . 15
17 6.3 Flame transmission test . 16
18 6.3.1 General . 16
19 6.3.2 Test mixtures . 16
20 7 Specific requirements for static flame arresters . 18
21 7.1 Construction requirements for prototype arresters . 18
22 7.2 Design series . 18
23 7.3 Flame transmission tests . 19
24 7.3.1 General . 19
25 7.3.2 Deflagration test . 19
26 7.3.3 Detonation test . 23
27 7.3.4 Short time burning test . 28
28 7.3.5 Endurance burning test . 31
29 7.4 Requirements for use of flame arresters . 32
30 7.4.1 General . 32
31 7.4.2 In-line deflagration flame arrester . 33
32 7.4.3 Pre-volume flame arrester . 33
33 7.4.4 Detonation flame arrester . 33
34 7.4.5 Short time burn flame arresters . 33
35 8 Specific requirements for liquid product detonation flame arresters . 34
36 8.1 Liquid seals . 34
37 8.2 Foot valves . 34
38 8.3 Flame transmission test . 35
39 9 Specific requirements for dynamic flame arresters (high velocity vent valves). 36
40 9.1 General . 36
41 9.2 Flame transmission tests . 37
42 9.2.1 Low flow flame transmission test . 37
43 9.2.2 Flame transmission test by opening and closing . 38
44 9.2.3 Deflagration test . 39
45 9.2.4 Endurance burning test . 39
46 10 Specific requirements for hydraulic flame arresters . 40
47 10.1 Equipment . 40

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48 10.2 Flame transmission tests . 40
49 10.2.1 General . 40
50 10.2.2 Short time burning test . 40
51 10.2.3 Deflagration test . 40
52 10.2.4 Detonation test . 41
53 11 Test of flame arresters installed on or within gas conveying equipment . 43
54 11.1 General . 43
55 11.2 Flame transmission tests . 43
56 11.2.1 General . 43
57 11.2.2 Test procedure for gas conveying equipment with inlet pressure
58 > 600 hPa . 45
59 11.2.3 Test procedure for gas conveying equipment with inlet pressure
60 ≤ 600 hPa . 46
61 12 Instructions . 46
62 13 Marking . 47
63 13.1 Location . 47
64 13.2 Flame arrester housing . 47
65 13.2.1 General information . 47
66 13.2.2 Warning markings . 48
67 13.2.3 Examples of marking . 49
68 13.3 Flame arrester element . 49
69 14 Manufacturing and production. 50
70 14.1 Construction . 50
71 14.2 Housing . 50
72 14.3 Joints . 50
73 14.4 Pressure test . 50
74 14.5 Leak test . 50
75 Annex A (normative) Flow measurement . 52
76 A.1 General . 52
77 A.2 In-line flame arresters . 52
78 A.3 End-of-line flame arrester . 53
79 A.3.1 General . 53
80 A.3.2 Special flow measurement for dynamic flame arresters . 54
81 A.4 Undamped oscillation tests of dynamic flame arrester (High velocity vent
82 valves) . 55
83 Annex B (informative) Information for selecting flame arresters. 57
84 Annex C (informative) Best practice . 58
85 Annex D (informative) Evaluation of test results . 59
86 Annex E (normative) Application . 60
87 E.1 General . 60
88 E.2 Limits for use for static flame arresters . 61
89 E.2.1 In-line flame arrester . 61
90 E.2.2 Pre-volume flame arrester . 61
91 E.2.3 Detonation flame arrester . 61
92 E.2.4 Short time burn flame arrester . 61
93 E.3 Limits for use for liquid detonation flame arresters . 62
94 E.4 Limits for use for dynamic flame arresters (high velocity vent valves). 62
95 E.5 Limits for use for hydraulic flame arresters . 62

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96 Bibliography . 65
97
98 Figure 1 – Test apparatus for end-of-line flame arrester for deflagration test . 20
99 Figure 2 – Test apparatus for in-line flame arrester for deflagration test. 21
100 Figure 3 – Test apparatus for pre-volume flame arrester for deflagration test . 22
101 Figure 4 – Test apparatus for detonation flame arrester for detonation without
102 restriction . 24
103 Figure 5 – Test apparatus for detonation flame arrester for detonation with restriction . 26
104 Figure 6 – Test apparatus for short time burning test . 29
105 Figure 7 – Test apparatus for endurance burning test . 31
106 Figure 8 – Liquid product detonation flame arrester . 34
107 Figure 9 – End-of-line flame arrester incorporating a non-return valve (foot valve) . 35
108 Figure 10 – Test apparatus for liquid product detonation flame arresters . 36
109 Figure 11 – Test apparatus for determining the non-hammering conditions for dynamic
110 flame arresters . 38
111 Figure 12 – Test apparatus for hydraulic flame arresters . 42
112 Figure 13 – Test apparatus for the flame transmission test of flame arresters installed
113 on or within gas conveying equipment . 44
114 Figure 14 – Example of marking plate, burn rating “a” . 49
115 Figure 15 – Example of marking plate, burn rating “b” . 49
116 Figure A.1 – Test apparatus for recording the pressure drop/flow rate curve for in-line
117 flame arresters . 53
118 Figure A.2 – Test apparatus for recording the pressure drop/flow rate curve for end-of-
119 line flame arresters with or without integrated pressure and/or vacuum valve . 54
120 Figure A.3 – Test apparatus for determining the non-oscillating conditions for dynamic
121 flame arresters . 56
122 Figure D.1 – Decision process for stable detonation arrester (DET3 and DET4) . 59
123 Figure D.2 – Decision process for unstable detonation arrester (DET1 and DET2) . 59
124 Figure E.1 – Test apparatus for hydraulic flame arresters . 64
125
126 Table 1 – Flame arrester classification for deflagration, stable and unstable detonation . 14
127 Table 2 – Summary of tests to be conducted. 15
128 Table 3 – Specification of gas-air mixtures for deflagration and detonation tests . 16
129 Table 4 – Specification of gas-air mixtures for short time burning tests and burning
130 tests of dynamic flame arresters . 17
131 Table 5 – Specification of gas-air or vapour-air mixtures for endurance burning tests of
132 static flame arresters . 17
133 Table 6 – Design series . 19
134 Table 7 – Ratio p /p . 25
md TB
135 Table 8 – Number of the individual tests and test parameters for the flame
136 transmission test of flame arresters installed on or within gas conveying equipment
137 with inlet pressures > 600 hPa . 45
138 Table 9 – Number of the individual tests and test parameters for the flame
139 transmission test of flame arresters installed on or within gas conveying equipment
140 with inlet pressures ≤ 600 hPa . 46
141 Table B.1 – Information for selecting flame arresters . 57
142

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143 INTERNATIONAL ELECTROTECHNICAL COMMISSION
144 ____________
145
146 EXPLOSIVE ATMOSPHERES - PART 49: FLAME ARRESTERS —
147 PERFORMANCE REQUIREMENTS, TEST METHODS AND LIMITS FOR USE
148
149
150
151
152 FOREWORD
153 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
154 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
155 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
156 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
157 Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
158 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
159 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
160 with the IEC also participate in this preparation. IEC collaborates closely with the International Organizati on for
161 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
162 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
163 consensus of opinion on the relevant subjects since each technical committee has representation from all
164 interested IEC National Committees.
165 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
166 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
167 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
168 misinterpretation by any end user.
169 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
170 transparently to the maximum extent possible in their national and regional publications. Any divergence between
171 any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
172 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
173 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
174 services carried out by independent certification bodies.
175 6) All users should ensure that they have the latest edition of this publication.
176 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
177 members of its technical committees and IEC National Committees for any personal injury, property damage or
178 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
179 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
180 Publications.
181 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
182 indispensable for the correct application of this publication.
183 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
184 rights. IEC shall not be held responsible for identifying any or all such patent rights.
185 International Standard ISO 80079-49 has been prepared by IEC sub-committee 31M: Non-
186 electrical equipment and protective systems for explosive atmospheres.
187 This edition cancels and replaces ISO 16852:2016, which has been technically revised.
188 This edition includes the following significant technical changes with respect to
189 ISO 16852:2016:
190 a) adaptation of the relevant IEC TC 31 requirements on standards;
191 b) modification of the upper limit of the temperature range from 150 °C to 200 °C under the
192 condition that T0 shall be not larger than 80 % of the auto ignition temperature of the gas -
193 air-mixture;
194 c) clarification of the conditions and requirements for flame arresters whose intended
195 operating conditions are outside the atmospheric conditions in clauses 7.3.4 and 7.3.5;

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196 d) clarification of the requirements on the information for use in clause 12.1 indent f
197 concerning the burn time;
198 e) addition of a permission to the construction requirements both in clause 7.1 and 13.1 to
199 substitute visual inspection by performing a flow test;
200 f) addition of a flow chart for the evaluation of test results as Annex D.
201

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202 INTRODUCTION
203 Flame arresters are safety devices fitted to openings of enclosures or to pipe work and are
204 intended to allow fluid flow but prevent flame transmission if a flammable mixture is ignited.
205 They have widely been used for decades in the chemical and oil industry, and a variety of
206 national standards is available. This Document was prepared with an aim to establish an
207 international basis by harmonizing and incorporating recent national developments and
208 standards as far as reasonable.
209 This document addresses performance requirements and test methods, as well as limits for use
210 for flame arresters.
211 Only the minimum safety requirements for flame arresters to prevent flame transmission are
212 specified.
213 The hazard identification of common applications found in industry leads to the specification of
214 the test methods. These test methods reflect standard practical situations and, as such, form
215 the heart of this Document because they also allow classification of the various types of flame
216 arresters and then determination of the limits of use.
217 A considerable number of test methods and test conditions had to be taken into account for two
218 main reasons.
219 a) Different types of flame arresters are covered with respect to the operating principle (static,
220 hydraulic, liquid, dynamic) and each type clearly needs its specific test set-up and test
221 procedure.
222 b) It is necessary to adapt flame arresters to the special conditions of application (gas,
223 installation) because of the conflicting demands of high flame quenching capability and low
224 pressure loss. This situation is completely different from the otherwise similar principle of
225 protection by flameproof enclosure, for example for electrical equipment, where the
226 importance of process gas flow through any gaps is negligible and importance is placed on
227 the flame quenching effect of the gap.
228 Consequently, in this Document, the testing and classification related to the Equipment Groups
229 and the installation conditions have been subdivided more than is usually the case in other
230 parts of the ISO/IEC 80079 and IEC 60079 series of standards. In particular,
231 • Equipment Group IIA is subdivided into sub-groups IIA1 and IIA,
232 • Equipment Group IIB is subdivided into sub-groups IIB1, IIB2, IIB3 and IIB, and
233 • the type “detonation arrester” is divided into four sub-types, which take into account specific
234 installation situations.
235 The test conditions lead to the limits for use which are most important for the user. This
236 Document specifies this safety relevant information and its dissemination through the
237 manufacturer's written instructions for use and the marking of the flame arr esters.
238 The limits for use are also a link to more general (operational) safety considerations and
239 regulations, which remain the responsibility the user and regulators. Annex B and Annex C offer
240 some guidance on these aspects.
241

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242 EXPLOSIVE ATMOSPHERES - PART 49: FLAME ARRESTERS —
243 PERFORMANCE REQUIREMENTS, TEST METHODS AND LIMITS FOR USE
244
245
246
247 1 Scope
248 This document specifies the requirements for flame arresters that prevent flame transmission
249 when explosive gas-air or vapour-air mixtu
...