oSIST prEN ISO/IEC 80079-41:2023

Explosive atmospheres - Part 41: Reciprocating internal combustion engines (ISO/IEC DIS 80079-41:2023)

This part of ISO/IEC 80079 covers the technical requirements necessary to avoid or minimize the significant hazards listed in Clause 4, which could occur during normal operation, maintenance or foreseeable malfunction of reciprocating internal combustion engines intended for use in explosive atmospheres including
- Group I EPL Mb for use in underground workings susceptible to firedamp and/or combustible dust,
- Group II EPL Gb and Gc for use in potentially explosive atmospheres of flammable gas and vapour and
- Group III EPL Db and Dc for use in potentially explosive atmospheres of combustible dust.
This part of ISO/IEC 80079 includes those tests of the engine and its ancillary devices that are required to verify compliance.
This part of ISO/IEC 80079 applies to reciprocating internal combustion engines with compression ignition and spark ignition.
This part of ISO/IEC 80079 does not define requirements relating to the driven machinery and equipment.
This part of ISO/IEC 80079 does not apply
- to flammable gas and vapour atmospheres containing carbon disulphide (CS2) and/or ethylene oxide (C2H4O) due to special properties of these gases;
- to explosive mixtures of vapours and gases, which tend to self-decompose (e.g. acetylene) or which are chemically unstable.This International standard does not apply to engines used in areas for the processing manufacture or storage of explosives;
- to gasoline engines and all other liquid injection spark ignited engines.
This part of ISO/IEC 80079 solely deals with explosion protection requirements. Requirements on emissions are not covered by this standard.
General safety requirements are not included in this International Standard.
NOTE 1   General safety requirements i.e. those common to internal combustion engines, are covered for the EU in EN 1679-1:1998+A1:2011.
This part of ISO/IEC 80079 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 engine can be operated are:
- temperature -20 °C to +40 °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 engine. In addition, the external atmosphere can be drawn inside the engine by natural breathing produced as a result of fluctuations in the engine's internal operating pressure, and/or temperature.
NOTE 2   It is considered that −20 °C to +40 °C is appropriate for most engines. However for equipment designed for outside this range IEC/TS 60079-43 should be considered.
NOTE 3   The requirements of this standard can also be helpful for the design, construction, testing and marking of engine 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, should clearly demonstrate and indicate the engine's suitability for the conditions it may encounter. It should also be recognized that changes in temperature and pressure can have a significant influence on characteristics of the explosive atmosphere, such as ignitability (see Annex I).
NOTE 4   Reciprocating internal combustion engines are not considered as pressure vessels.

Explosionsfähige Atmosphären - Teil 41: Hubkolben-Verbrennungsmotoren (ISO/IEC DIS 80079-41:2023)

Atmosphères explosives - Partie 41: Moteurs alternatifs à combustion interne (ISO/IEC DIS 80079-41:2023)

Eksplozivne atmosfere - 41. del: Batni motorji z notranjim zgorevanjem (ISO/IEC DIS 80079-41:2023)

General Information

• Status: Not Published
• Public Enquiry End Date: 29-Jun-2023
• ICS: 13.230 - Explosion protection
• ICS: 27.020 - Internal combustion engines
• ICS: 29.260.20 - Electrical apparatus for explosive atmospheres
• Technical Committee: EXP - Electrical apparatus for explosive atmospheres
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 03-May-2023
• Due Date: 20-Sep-2023
• Completion Date: 25-Jul-2023
• Directive: 2006/42/EC - Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast)
• Directive: 2014/34/EU - Directive 2014/34/EU Of The European Parliament And Of The Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres (recast)
• Mandate: M/396 - Mandate to CEN and Cenelec for standardisation in the field of machinery
• Mandate: M/BC/CEN/92/46 - Standardization mandate assigned to CEN/CENELEC concerning equipment and protective systems intended for use in potentially explosive atmospheres
• Ref Project: prEN ISO/IEC 80079-41 - Explosive atmospheres - Part 41: Reciprocating internal combustion engines (ISO/IEC DIS 80079-41:2023)

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO/IEC 80079-41:2023
01-junij-2023
Eksplozivne atmosfere - 41. del: Batni motorji z notranjim zgorevanjem (ISO/IEC
DIS 80079-41:2023)
Explosive atmospheres - Part 41: Reciprocating internal combustion engines (ISO/IEC
DIS 80079-41:2023)
Explosionsfähige Atmosphären - Teil 41: Hubkolben-Verbrennungsmotoren (ISO/IEC
DIS 80079-41:2023)
Atmosphères explosives - Partie 41: Moteurs alternatifs à combustion interne (ISO/IEC
DIS 80079-41:2023)
Ta slovenski standard je istoveten z: prEN ISO/IEC 80079-41
ICS:
13.230 Varstvo pred eksplozijo Explosion protection
27.020 Motorji z notranjim Internal combustion engines
zgorevanjem
29.260.20 Električni aparati za Electrical apparatus for
eksplozivna ozračja explosive atmospheres
oSIST prEN ISO/IEC 80079-41:2023 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 80079-41:2023

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oSIST prEN ISO/IEC 80079-41:2023
DRAFT INTERNATIONAL STANDARD
ISO/IEC DIS 80079-41
ISO/TMBG Secretariat: ISO
Voting begins on: Voting terminates on:
2023-04-21 2023-07-14
Explosive atmospheres —
Part 41:
Reciprocating internal combustion engines
ICS: 29.260.20; 27.020
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.
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oSIST prEN ISO/IEC 80079-41:2023
ISO/IEC DIS 80079-41:2023(E)
DRAFT INTERNATIONAL STANDARD
ISO/IEC DIS 80079-41
ISO/TMBG Secretariat: ISO
Voting begins on: Voting terminates on:
2023-04-21 2023-07-14
Explosive atmospheres —
Part 41:
Reciprocating internal combustion engines
ICS: 29.260.20; 27.020
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.
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NATIONAL REGULATIONS.
Website: www.iso.org ISO/IEC DIS 80079-41:2023(E)
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ii
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oSIST prEN ISO/IEC 80079-41:2023
31M/182/CDV – 2 – ISO/IEC 80079-41 © IEC:2023
1 CONTENTS
2
3 1 Scope . 8
4 2 Normative references . 9
5 3 Definitions . 10
6 4 Ignition hazards . 12
7 5 Safety requirements and/or measures . 13
8 5.1 For all equipment protection levels (EPLs) . 13
9 5.1.1 General . 13
10 5.1.2 Ignition hazard assessment . 13
11 5.1.3 Joints . 14
12 5.1.4 Electrical systems . 14
13 5.1.5 Static electricity and bonding requirements . 16
14 5.1.6 Safety and automation systems . 17
15 5.1.7 Flame arresters . 24
16 5.1.8 Spark arresters . 26
17 5.1.9 Engine gas path configuration . 27
18 5.1.10 Fuel system . 29
19 5.1.11 Mechanically generated sparks . 30
20 5.2 Specific requirements for EPL Mb . 31
21 5.2.1 Maximum temperature . 31
22 5.2.2 Gas path . 31
23 5.2.3 Air intake system . 31
24 5.2.4 Exhaust system . 31
25 5.2.5 Fans and other rotating components . 31
26 5.2.6 Compressed air systems. 31
27 5.3 Specific requirements for EPL Gb and EPL Gc . 32
28 5.3.1 Maximum temperature . 32
29 5.3.2 Configuration of flame arresters & spark arresters . 32
30 5.3.3 Gas path . 33
31 5.3.4 Air intake system . 33
32 5.3.5 Exhaust system . 34
33 5.4 Specific requirements for EPL Db and EPL Dc . 34
34 5.4.1 Maximum temperature . 34
35 5.4.2 Air intake system . 34
36 5.4.3 Exhaust system . 34
37 5.4.4 Cold start devices . 35
38 5.4.5 Mechanically generated sparks . 35
39 5.4.6 Compressed air systems. 35
40 6 EPL Gc gaseous fuelled spark ignited engine . 35
41 6.1 General . 35
42 6.1.1 Differences between spark ignited, gas fuelled engines and
43 compression ignition engines . 35
44 6.1.2 Fuel System . 36
45 6.2 Ignition system . 36
46 6.3 Safe Starting Purge . 36
47 6.3.1 Ventilation . 36

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48 6.3.2 Engine starting . 36
49 6.3.3 Engine stopping . 37
50 7 Test setup and testing procedures . 37
51 7.1 General . 37
52 7.2 Documentation . 37
53 7.3 Engine operation . 37
54 7.4 Measuring instruments . 37
55 7.5 Temperature measurement . 37
56 7.5.1 Purpose of the test . 37
57 7.5.2 Test procedure . 37
58 7.5.3 Acceptance criteria . 38
59 7.5.4 (Type) Test report / protocol . 39
60 7.6 Pressure determination . 39
61 7.6.1 General . 39
62 7.6.2 Test procedure . 39
63 7.6.3 (Type) Test report . 42
64 7.7 Over pressure test (Gc, Gb and Mb) . 42
65 7.7.1 General . 42
66 7.7.2 Test procedure static test . 43
67 7.7.3 Test procedure alternative dynamic test . 43
68 7.8 Propagation testing . 45
69 7.8.1 General . 45
70 7.8.2 Test set-up . 45
71 7.8.3 Non-transmission test procedure intake system . 48
72 7.8.4 Non-transmission test procedure exhaust side . 50
73 7.9 Crankcase explosion containment testing . 51
74 7.9.1 General . 51
75 7.9.2 Apparatus . 51
76 7.9.3 Test procedure . 52
77 7.9.4 Acceptance criteria . 52
78 7.9.5 Dry type - spark arrester tests (according to 1834-1:2006, 6.4.2) . 52
79 7.9.6 Liquid type – spark arrester tests . 52
80 7.10 Static electricity / Non-metallic material . 53
81 7.11 Verification engine control, alarms and shutdown . 53
82 7.12 Leak test for ducts . 53
83 8 Instructions . 53
84 8.1 Accompanying documents . 53
85 8.1.1 Group I Mining . 53
86 8.1.2 Group II Flammable gas and vapours . 53
87 8.1.3 Group III Combustible dust . 53
88 8.2 Inspection check list . 54
89 8.2.1 Group I Mining . 54
90 8.2.2 Group II Flammable gas and vapours . 54
91 8.2.3 Group III Combustible dust . 55
92 9 Marking . 55
93 9.1.1 General . 55
94 9.1.2 EPL Mb . 56
95 9.1.3 EPL Gb and EPL Gc . 56
96 9.1.4 EPL Db and EPL Dc . 56

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97 Annex A (informative) Engine conditions and ignition sources – Group I equipment . 57
98 A.1 Engine conditions . 57
99 A.1.1 Normal operating conditions . 57
100 A.1.2 Expected malfunctions . 57
101 A.1.3 Rare malfunctions . 57
102 A.2 Ignition sources . 57
103 A.2.1 Hot surfaces . 57
104 A.2.2 Flame and hot gases . 58
105 A.2.3 Sparks . 58
106 A.2.4 Adiabatic compression . 58
107 Annex B (informative) Engine conditions and ignition sources – Group II and Group III
108 equipment – Flammable gas, vapour and combustible dust atmospheres . 59
109 B.1 General . 59
110 B.2 Engine conditions . 59
111 B.2.1 Normal operating conditions . 59
112 B.2.2 Foreseeable malfunctions . 59
113 B.2.3 Rare malfunctions . 59
114 B.3 Ignition sources . 60
115 B.3.1 Hot surfaces . 60
116 B.3.2 Flame and hot gases . 60
117 B.3.3 Sparks . 60
118 B.3.4 Adiabatic compression . 60
119 Annex C (informative) Ignition hazard assessment for reciprocating internal
120 combustion engines . 61
121 C.1 General requirements . 61
122 C.2 Procedure of ignition hazard assessment . 61
123 C.3 Ignition hazard assessment report . 62
124 Annex D (informative) Identification of Ignition Hazards . 63
125 Annex E (informative) Test reports . 89
126 Annex F (normative) Test set up schematics . 108
127 Annex G (informative) Engine types . 126
128
129 Figure 1 – Basic gas path configurations . 29
130 Figure 2 – Maximum explosion pressure and Dynamic overpressure test - minimal
131 representation. 41
132 Figure 3 – Non-transmission test . 46
133 Figure F.1 – Explosion pressure on the exhaust side under atmospheric condition in a
134 pressure resistant chamber . 109
135 Figure F.2 – Explosion pressure on the exhaust side under atmospheric condition in a
136 closed pipe . 110
137 Figure F.3 – Flame transmission on the exhaust side under atmospheric conditions in a
138 plastic bag and heated flame arresters . 112
139 Figure F.4 – Flame transmission on the exhaust side under atmospheric conditions in
140 an explosion proof chamber and heated flame arresters . 113
141 Figure F.5 – Flame transmission on the exhaust side under atmospheric conditions
142 with plastic bags . 115
143 Figure F.6 – Explosion pressure on the Intake side under atmospheric conditions . 116

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144 Figure F.7 – Explosion pressure on the intake side under overpressure conditions in a
145 plastic bag . 118
146 Figure F.8 – Explosion pressure on the intake side under overpressure conditions in an
147 explosion proof chamber . 119
148 Figure F.9 – Explosion pressure on the intake side under overpressure conditions in a
149 closed pipe . 121
150 Figure F.10 – Flame transmission on the intake side under atmospheric conditions in a
151 plastic bag . 122
152 Figure F.11 – Flame transmission on the intake side under overpressure conditions in
153 an explosion proof chamber . 124
154 Figure F.12 – Flame transmission on the intake side under overpressure conditions in
155 a closed pipe . 125
156 Figure G.1 – Engine types . 127
157 Figure G.2 – Engine types – Fuels used . 128
158
159 Table 1 – Minimum level of Protection, equipment group, and ingress protection (IP)
160 relationship . 15
161 Table 2 – Minimum integrity for a safety device for ignition source control . 20
162 Table 3 – Alarms and Shutdown . 21
163 Table 4 – Classification of maximum temperatures . 32
164 Table 5 – Configuration of Gb and Gc flame arresters & spark arresters . 33
165 Table 4 – Test mixture for the determination of maximum explosion pressures . 40
166 Table 5 – Test mixtures for Propagation Tests . 47
167 Table D.1 – Possible ignition sources . 63
168 Table D.2 – Gc and Dc example . 65
169 Table D.3 – Gb, Db & Mb example . 76
170
171
172

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oSIST prEN ISO/IEC 80079-41:2023
31M/182/CDV – 6 – ISO/IEC 80079-41 © IEC:2023
173 INTERNATIONAL ELECTROTECHNICAL COMMISSION
174 ____________
175
176 Explosive atmospheres
177
178 Part 41: Reciprocating internal combustion engines
179
180 FOREWORD
181 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
182 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
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190 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
191 consensus of opinion on the relevant subjects since each technical committee has representation from all
192 interested IEC National Committees.
193 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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209 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
210 indispensable for the correct application of this publication.
211 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
212 rights. IEC shall not be held responsible for identifying any or all such patent rights.
213 International Standard ISO/IEC 80079-41 has been prepared by ISO/IEC subcommittee 31M:
214 Non-electrical equipment and protective systems for explosive atmospheres.
215 The text of this standard is based on the following documents:
FDIS Report on voting
31M/XX/FDIS 31M/XX/RVD
216
217 Full information on the voting for the approval of this standard can be found in the report on
218 voting indicated in the above table.
219 This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
220 The committee has decided that the contents of this publication will remain unchanged until the
221 stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
222 the specific publication. At this date, the publication will be
223 • reconfirmed,

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224 • withdrawn,
225 • replaced by a revised edition, or
226 • amended.
227
228 The National Committees are requested to note that for this publication the stability date
229 is 2020.
230 THIS TEXT IS INCLUDED FOR THE INFORMATION OF THE NATIONAL COMMITTEES AND WILL BE DELETED
231 AT THE PUBLICATION STAGE.
232

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31M/182/CDV – 8 – ISO/IEC 80079-41 © IEC:2023
233 Explosive atmospheres
234
235 Part 41: Reciprocating internal combustion engines
236
237 1 0BScope
238 This part of ISO/IEC 80079 specifies the technical require
...