SIST EN ISO/IEC 80079-20-1:2020
(Main)Explosive atmospheres - Part 20-1: Material characteristics for gas and vapour classification - Test methods and data (ISO/IEC 80079-20-1:2017)
Explosive atmospheres - Part 20-1: Material characteristics for gas and vapour classification - Test methods and data (ISO/IEC 80079-20-1:2017)
This part of ISO/IEC 80079 provides guidance on classification of gases and vapours. It describes a test method intended for the measurement of the maximum experimental safe gaps (MESG) for gas-air mixtures or vapour-air mixtures under normal conditions of temperature and pressure (20 °C, 100 kPa) so as to permit the selection of an appropriate group of equipment. The standard describes also a test method intended for use in the determination of the auto-ignition temperature (AIT) of a vapour-air mixture or gas-air mixture at atmospheric pressure, so as to permit the selection of an appropriate temperature class of equipment.
Values of chemical properties of materials are provided to assist in the selection of equipment to be used in hazardous areas. Further data may be added as the results of validated tests become available.
The materials and the characteristics included in a table (see Annex B) have been selected with particular reference to the use of equipment in hazardous areas. The data in this standard have been taken from a number of references which are given in the bibliography.
These methods for determining the MESG or the AIT may also be used for gas-air-inert mixtures or vapour-air-inert mixtures. However, data on air-inert mixtures are not tabulated.
Explosionsfähige Atmosphären - Stoffliche Eigenschaften zur Klassifizierung von Gasen und Dämpfen - Teil 20-1: Prüfverfahren und Daten (ISO/IEC 80079-20-1:2017)
Dieser Teil von ISO/IEC 80079 dient als Hilfestellung bei der Klassifizierung von Gasen und Dämpfen. Er beschreibt ein Prüfverfahren zur Messung der Normspaltweite (NSW) für Gas oder Dampf-Luft-Gemische unter Laborbedingungen von Temperatur und Druck (20° C; 101,3 kPa) und ermöglicht somit die Einteilung in die zutreffende Explosionsgruppe. Dieses Dokument beschreibt auch ein Prüfverfahren zur Bestimmung der Zündtemperatur (Tz) eines Dampf-Luft-Gemisches oder Gas-Luft-Gemisches bei Atmosphärendruck, um so Geräte der geeigneten Temperaturklasse auszuwählen.
Daten physikochemischer Eigenschaften von Stoffen werden bereitgestellt als Hilfestellung für die Auswahl der in explosionsgefährdeten Bereichen einzusetzenden Geräte. Weitere Daten, die durch validierte Prüfungen erhalten wurden, dürfen künftig hinzugefügt werden.
Die Stoffe und die in einer Tabelle (siehe Anhang B) aufgeführten Eigenschaften wurden vor allem im Hinblick auf den Einsatz von Geräten in explosionsgefährdeten Bereichen ausgewählt. Die Daten in diesem Dokument wurden verschiedener Quellen entnommen, die in den Literaturhinweisen aufgeführt sind.
Die Verfahren zur Bestimmung der NSW oder der Tz dürfen auch für Gas-Luft-Inertgas-Gemische oder Dampf-Luft-Inertgas-Gemische eingesetzt werden. Daten über Luft-Inertgas-Gemische sind jedoch nicht in der Tabelle aufgeführt
Atmosphères explosives - Partie 20-1: Caractéristiques des produits pour le classement des gaz et des vapeurs - Méthodes et données d'essai (ISO/IEC 80079-20-1:2017)
ISO/IEC 80079-20-1:2017 est publiée en tant que norme sous double logo et donne des recommandations pour le classement des gaz et des vapeurs. Elle décrit une méthode d'essai destinée à mesurer les interstices expérimentaux maximaux de sécurité (IEMS ou MESG maximum experimental safe gaps) des mélanges gaz-air ou vapeur-air dans des conditions normales de température et de pression (20 °C, 101,3 kPa) afin de pouvoir choisir un groupe approprié d'appareils. Le présent document décrit également une méthode d'essai qui permet d'établir la température dauto-inflammation (TAI ou AIT auto-ignition temperature) d'un mélange vapeur-air ou gaz-air à la pression atmosphérique, afin de pouvoir choisir une classe de température appropriée des appareils. Les valeurs des propriétés chimiques des produits sont fournies pour faciliter le choix des appareils à utiliser dans les emplacements dangereux. Des données supplémentaires peuvent être ajoutées au fur et à mesure de lobtention de résultats dessai validés. Les produits et les caractéristiques indiqués dans un tableau (voir lAnnexe B) ont été choisis tout particulièrement pour l'utilisation d'appareils dans des emplacements dangereux. Les données fournies dans le présent document sont extraites dun certain nombre de documents de référence qui sont cités dans la bibliographie. Ces méthodes de détermination de lIEMS ou détablissement de la TAI peuvent être également appliquées pour les mélanges gaz-air-matière inerte ou les mélanges vapeur-air-matière inerte. Les données relatives aux mélanges air-matière inerte ne sont toutefois pas fournies.
Mots clés: classement des gaz et des vapeurs, mesurer les interstices expérimentaux maximaux de sécurité (IEMS ou MESG)
Eksplozivne atmosfere - 20-1. del: Lastnosti materiala in razvrstitev za pline in hlape - Preskusne metode in podatki (ISO/IEC 80079-20-1:2017)
Ta del standarda ISO/IEC 80079 podaja smernice glede razvrstitve plinov in hlapov. Opisuje preskusno metodo, namenjeno merjenju največjih poskusnih varnih vrzeli (MESG) za zmesi plinov in zraka ali zmesi hlapov in zraka v normalnih pogojih temperature in tlaka (20 °C, 100 kPa), da se omogoči izbira ustrezne skupine opreme. Standard opisuje tudi preskusno metodo, ki se uporablja za določanje temperature samovžiga (AIT) zmesi hlapov in zraka ali plinov in zraka pri atmosferskem tlaku, da se omogoči izbira ustreznega temperaturnega razreda opreme. Navedene so vrednosti kemijskih lastnosti materialov, ki so namenjene kot pomoč pri izbiri opreme za uporabo v nevarnih območjih. Ko bodo na voljo rezultati potrjenih testov, se lahko dodajo dodatni podatki. Materiali in značilnosti, vključene v tabelo (glej dodatek B), so bile izbrane s posebnim poudarkom na uporabi opreme v nevarnih območjih. Podatki v tem standardu so vzeti iz številnih referenc, ki so podane v bibliografiji. Te metode za določanje MESG ali AIT se lahko uporabljajo tudi za zmesi plinov, zraka in inertnih plinov ali zmesi hlapov, zraka in inertnih plinov. Vendar podatki o zmeseh zraka in inertnih plinov niso tabelirani.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO/IEC 80079-20-1:2020
01-februar-2020
Eksplozivne atmosfere - 20-1. del: Lastnosti materiala in razvrstitev za pline in
hlape - Preskusne metode in podatki (ISO/IEC 80079-20-1:2017)
Explosive atmospheres - Part 20-1: Material characteristics for gas and vapour
classification - Test methods and data (ISO/IEC 80079-20-1:2017)
Explosionsfähige Atmosphären - Stoffliche Eigenschaften zur Klassifizierung von Gasen
und Dämpfen - Teil 20-1: Prüfverfahren und Daten (ISO/IEC 80079-20-1:2017)
Atmosphères explosives - Partie 20-1: Caractéristiques des produits pour le classement
des gaz et des vapeurs - Méthodes et données d'essai (ISO/IEC 80079-20-1:2017)
Ta slovenski standard je istoveten z: EN ISO/IEC 80079-20-1:2019
ICS:
29.260.20 Električni aparati za Electrical apparatus for
eksplozivna ozračja explosive atmospheres
SIST EN ISO/IEC 80079-20-1:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO/IEC 80079-20-1:2020
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SIST EN ISO/IEC 80079-20-1:2020
EN ISO/IEC 80079-20-1
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2019
EUROPÄISCHE NORM
ICS 29.260.20 Supersedes EN 60079-20-1:2010
English Version
Explosive atmospheres - Part 20-1: Material
characteristics for gas and vapour classification - Test
methods and data (ISO/IEC 80079-20-1:2017, including
Cor 1:2018)
Atmosphères explosives - Partie 20-1 : Caractéristiques Explosionsfähige Atmosphären - Stoffliche
des produits pour le classement des gaz et des vapeurs Eigenschaften zur Klassifizierung von Gasen und
- Méthodes et données d'essai (ISO/CEI 80079-20- Dämpfen - Teil 20-1: Prüfverfahren und Daten
1:2017, y compris Cor 1:2018) (ISO/IEC 80079-20-1:2017, einschließlich Cor 1:2018)
This European Standard was approved by CEN on 8 January 2018.
This European Standard was corrected and reissued by the CEN-CENELEC Management Centre on 20 November 2019.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N
EUROPÄISCHES KOMITEE FÜR NORMUN G
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO/IEC 80079-20-1:2019 E
worldwide for CEN national Members.
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SIST EN ISO/IEC 80079-20-1:2020
EN ISO/IEC 80079-20-1:2019 (E)
Contents Page
European foreword . 3
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2014/34/EU aimed to be covered . 4
2
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SIST EN ISO/IEC 80079-20-1:2020
EN ISO/IEC 80079-20-1:2019 (E)
European foreword
This document (EN ISO/IEC 80079-20-1:2019) has been prepared by Technical Committee ISO/TMB
"Technical Management Board - groups" in collaboration with Technical Committee CEN/TC 305
“Potentially explosive atmospheres - Explosion prevention and protection” the secretariat of which is
held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by April 2020, and conflicting national standards shall be
withdrawn at the latest by April 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 60079-20-1:2010.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For the relationship with EU Directive(s) see informative Annex ZA, which is an integral part of this
document.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO/IEC 80079-20-1:2017, including Cor 1:2018 has been approved by CEN as
EN ISO/IEC 80079-20-1:2019 without any modification.
3
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SIST EN ISO/IEC 80079-20-1:2020
EN ISO/IEC 80079-20-1:2019 (E)
Annex ZA
(informative)
Relationship between this European Standard and the essential
requirements of Directive 2014/34/EU aimed to be covered
This European Standard has been prepared under a Commission’s standardization request
M/BC/CEN/92/46 to provide one voluntary means of conforming to essential requirements of 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)”.
Once this standard is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this standard given in Table ZA.1 confers, within the limits of
the scope of this standard, a presumption of conformity with the corresponding essential requirements
of that Directive, and associated EFTA regulations.
Table ZA.1 — Correspondence between this European Standard and Directive 2014/34/EU
Essential Requirements of Clause(s)/sub-clause(s) of Remarks/Notes
Directive 2014/34/EU this EN
1.0.1 All clauses
WARNING 1 — Presumption of conformity stays valid only as long as a reference to this European
Standard is maintained in the list published in the Official Journal of the European Union. Users of this
standard should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2 — Other Union legislation may be applicable to the product(s) falling within the scope of
this standard.
4
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SIST EN ISO/IEC 80079-20-1:2020
ISO/IEC 80079-20-1
Edition 1.0 2017-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Explosive atmospheres –
Part 20-1: Material characteristics for gas and vapour classification – Test
methods and data
Atmosphères explosives –
Partie 20-1: Caractéristiques des produits pour le classement des gaz et des
vapeurs – Méthodes et données d'essai
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.230; 29.260.20 ISBN 978-2-8322-5164-5
Warning! Make sure that you obtained this publication from an authorized distributor.
Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.
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CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Classification of gases and vapours . 9
4.1 General . 9
4.2 Classification according to the maximum experimental safe gap (MESG) . 9
4.3 Classification according to the minimum igniting current ratio (MIC ratio) . 10
4.4 Classification according to the similarity of chemical structure . 10
4.5 Classification of mixtures of gases . 10
5 Data for flammable gases and vapours, relating to the use of equipment . 11
5.1 Determination of the properties . 11
5.1.1 General . 11
5.1.2 Equipment group . 11
5.1.3 Flammable limits . 11
5.1.4 Flash point (FP) . 11
5.1.5 Temperature class . 12
5.1.6 Minimum igniting current (MIC) . 12
5.1.7 Auto-ignition temperature (AIT) . 12
5.2 Properties of particular gases and vapours . 12
5.2.1 Coke oven gas . 12
5.2.2 Ethyl nitrite . 12
5.2.3 MESG of carbon monoxide . 12
5.2.4 Methane, Equipment Group IIA . 13
6 Method of test for the maximum experimental safe gap (MESG) . 13
6.1 Outline of method . 13
6.2 Test apparatus . 13
6.2.1 General . 13
6.2.2 Material and mechanical strength . 14
6.2.3 Exterior chamber . 14
6.2.4 Interior chamber . 14
6.2.5 Gap adjustment . 14
6.2.6 Injection of mixture . 14
6.2.7 Position of ignition source . 14
6.3 Procedure . 14
6.3.1 Preparation of gas mixtures . 14
6.3.2 Temperature and pressure . 14
6.3.3 Gap adjustment . 15
6.3.4 Ignition . 15
6.3.5 Observation of the ignition process . 15
6.4 Determination of maximum experimental safe gap (MESG) . 15
6.4.1 General . 15
6.4.2 Preliminary tests . 15
6.4.3 Confirmatory tests . 15
6.4.4 Reproducibility of maximum experimental safe gaps (MESG) . 15
6.4.5 Tabulated values . 16
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6.5 Verification of the MESG determination method . 16
7 Method of test for auto-ignition temperature (AIT) . 16
7.1 Outline of method . 16
7.2 Apparatus . 16
7.2.1 General . 16
7.2.2 Test vessel and support . 17
7.2.3 Thermocouples . 17
7.2.4 Oven . 17
7.2.5 Metering devices . 18
7.2.6 Mirror . 18
7.2.7 Timer . 18
7.2.8 Equipment for purging the test vessel with air . 18
7.2.9 Automated apparatus . 18
7.3 Sampling, preparation and preservation of test samples . 19
7.3.1 Sampling . 19
7.3.2 Preparation and preservation . 19
7.4 Procedure . 19
7.4.1 General . 19
7.4.2 Sample injection . 20
7.4.3 Determination of the auto-ignition temperature (AIT) . 20
7.5 Auto-ignition temperature (AIT) . 21
7.6 Validity of results . 21
7.6.1 Repeatability . 21
7.6.2 Reproducibility . 21
7.7 Data . 22
7.8 Verification of the auto-ignition temperature determination method . 22
Annex A (normative) Ovens of test apparatus for the tests of auto-ignition temperature . 23
A.1 General . 23
A.2 “IEC oven” . 23
A.3 “DIN oven” . 23
Annex B (informative) Tabulated values . 30
Annex C (informative) Determination of cool flames . 84
Annex D (informative) Volume dependence of auto-ignition temperature . 86
Bibliography . 87
Figure 1 − Test apparatus . 13
Figure A.1 − Test apparatus: assembly . 24
Figure A.2 − Section A-A (flask omitted) . 25
Figure A.3 − Base heater (board made of refractory material) . 25
Figure A.4 − Flask guide ring (board made of refractory material) . 26
Figure A.5 − Neck heater (board made of refractory material) . 26
Figure A.6 − Oven . 27
Figure A.7 − Lid of steel cylinder . 28
Figure A.8 − Lid of steel cylinder . 29
Figure A.9 − Injection of gaseous sample. 29
Figure C.1 − Additional thermocouple to detect cool flames . 84
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Figure C.2 − ‘Negative temperature coefficient’ shown for butyl butyrate as an example . 85
Figure D.1 − Volume dependence of auto-ignition temperature . 86
Table 1 − Classification of temperature class and range of auto-ignition temperatures . 12
Table 2 − Values for verification of the apparatus . 16
Table 3 − Values for verification of the apparatus . 22
Table B.1 − Material data . 32
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHERES –
Part 20-1: Material characteristics for gas and vapour classification –
Test methods and data
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard ISO/IEC 80079-20-1 has been prepared by subcommittee 31M: Non-
electrical equipment and protective systems for explosive atmospheres, of IEC technical
committee 31: Equipment for explosive atmospheres.
This first edition of ISO/IEC 80079-20-1 cancels and replaces IEC 60079-20-1:2010. It
constitutes a technical revision. No significant changes were made with respect to
IEC 60079-20-1:2010.
It is published as a double logo standard.
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The text of this standard is based on the following documents:
FDIS Report on voting
31M/122/FDIS 31M/126/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60079 series, under the general title: Explosive atmospheres, as
well as the International Standard 80079 series, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
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ISO/IEC 80079-20-1:2017 © ISO/IEC 2017 − 7 −
EXPLOSIVE ATMOSPHERES –
Part 20-1: Material characteristics for gas and vapour classification –
Test methods and data
1 Scope
This part of ISO/IEC 80079 provides guidance on classification of gases and vapours. It
describes a test method intended for the measurement of the maximum experimental safe
gaps (MESG) for gas-air mixtures or vapour-air mixtures under normal conditions of
temperature and pressure (20 °C, 101,3 kPa) so as to permit the selection of an appropriate
group of equipment. This document also describes a test method intended for use in the
determination of the auto-ignition temperature (AIT) of a vapour-air mixture or gas-air mixture
at atmospheric pressure, so as to permit the selection of an appropriate temperature class of
equipment.
Values of chemical properties of materials are provided to assist in the selection of equipment
to be used in hazardous areas. Further data may be added as the results of validated tests
become available.
The materials and the characteristics included in a table (see Annex B) have been selected
with particular reference to the use of equipment in hazardous areas. The data in this
document have been taken from a number of references which are given in the bibliography.
These methods for determining the MESG or the AIT may also be used for gas-air-inert
mixtures or vapour-air-inert mixtures. However, data on air-inert mixtures are not tabulated.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 60050-426, International Electrotechnical Vocabulary − Part 426: Electrical apparatus for
explosive atmospheres (available at http://www.electropedia.org/)
IEC 60079-11, Explosive atmospheres − Part 11: Equipment protection by intrinsic safety "i"
IEC 60079-14, Explosive atmospheres − Part 14: Electrical installations design, selection and
erection
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-426 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
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3.1
auto-ignition
reaction which is evidenced by a clearly perceptible flame and/or explosion, and for which the
ignition delay time does not exceed 5 min
Note 1 to entry: See 7.2.2 for a test method.
3.2
ignition delay time
time between the completed injection of the flammable material and the ignition
3.3
auto-ignition temperature
AIT
lowest temperature (of a surface) at which under specified test conditions an ignition of a
flammable gas or vapour in mixture with air or air-inert gas occurs
Note 1 to entry: See Clause 7 for a test method.
3.4
maximum experimental safe gap
MESG
maximum gap of a joint of 25 mm in width which prevents any transmission of an explosion
during tests made under the conditions specified in this document
Note 1 to entry: See Clause 6 for a test method.
3.5
minimum ignition current
MIC
minimum current in a specified test circuit that causes the ignition of the explosive test
mixture in the spark test apparatus according to IEC 60079-11
Note 1 to entry: See 5.1.6 for the test circuit.
3.6
flammable limits
lower flammable limit (LFL) and upper flammable limit (UFL) of gas in a gas-air mixture,
between which a flammable mixture is formed
Note 1 to entry: The term “explosive limits” is used especially in European standardization and regulations
interchangeably to describe these limits.
Note 2 to entry: The concentration can be expressed as either a vol
...
SLOVENSKI STANDARD
oSIST prEN ISO/IEC 80079-20-1:2016
01-februar-2016
Eksplozivne atmosfere - 20-1. del: Lastnosti materiala in razvrstitev za pline in
hlape - Preskusne metode in podatki (ISO/IEC/DIS 80079-20-1:2015)
Explosive atmospheres - Part 20-1: Material characteristics for gas and vapour
classification - Test methods and data (ISO/IEC/DIS 80079-20-1:2015)
Atmosphères explosives - Partie 20-1: Caractéristiques des produits pour le classement
des gaz et des vapeurs - Méthodes et données d'essai (ISO/IEC/DIS 80079-20-1:2015)
Ta slovenski standard je istoveten z: prEN ISO/IEC 80079-20-1
ICS:
29.260.20 (OHNWULþQLDSDUDWL]D Electrical apparatus for
HNVSOR]LYQDR]UDþMD explosive atmospheres
oSIST prEN ISO/IEC 80079-20-1:2016 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 80079-20-1:2016
DRAFT INTERNATIONAL STANDARD
ISO/DIS 80079-20-1
ISO/TMBG Secretariat: ISO
Voting begins on: Voting terminates on:
2015-12-03 2016-03-03
Explosive atmospheres —
Part 20-1:
Material characteristics for gas and vapour classification —
Test methods and data
Atmosphères explosives —
Partie 20-1: Caractéristiques des produits pour le classement des gaz et des vapeurs — Méthodes et
données d’essai
ICS: 29.260.20
ISO/CEN PARALLEL PROCESSING
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as defined in the Vienna Agreement.
This draft is hereby submitted to the ISO member bodies and to the CEN member
bodies for a parallel five month enquiry.
Should this draft be accepted, a final draft, established on the basis of comments
received, will be submitted to a parallel two-month approval vote in ISO and
THIS DOCUMENT IS A DRAFT CIRCULATED
formal vote in CEN.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
To expedite distribution, this document is circulated as received from the
IN ADDITION TO THEIR EVALUATION AS
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composition will be undertaken at publication stage.
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ISO/DIS 80079-20-1:2015(E)
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©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2015
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oSIST prEN ISO/IEC 80079-20-1:2016
ISO/DIS 80079-20-1:2015(E)
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ii © ISO/IEC 2015 – All rights reserved
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1 CONTENTS
2
3 FOREWORD . 5
4 1 Scope . 7
5 2 Normative references . 7
6 3 Terms and definitions . 7
7 4 Classification of gases and vapours. 9
8 4.1 General . 9
9 4.2 Classification according to the maximum experimental safe gaps (MESG) . 9
10 4.3 Classification according to the minimum igniting current ratio (MIC ratio) . 9
11 4.4 Classification according to a similarity of chemical structure . 10
12 4.5 Classification of mixtures of gases . 10
13 5 Data for flammable gases and vapours, relating to the use of equipment . 10
14 5.1 Determination of the properties . 10
15 5.1.1 General . 10
16 5.1.2 Equipment group . 10
17 5.1.3 Flammable limits . 10
18 5.1.4 Flash point FP . 11
19 5.1.5 Temperature class . 11
20 5.1.6 Minimum igniting current (MIC) . 11
21 5.1.7 Auto-ignition temperature (AIT) . 11
22 5.2 Properties of particular gases and vapours . 11
23 5.2.1 Coke oven gas . 11
24 5.2.2 Ethyl nitrite . 11
25 5.2.3 MESG of carbon monoxide . 12
26 5.2.4 Methane, Group IIA . 12
27 6 Method of test for the maximum experimental safe gap (MESG) . 12
28 6.1 Outline of method . 12
29 6.2 Test apparatus . 12
30 6.2.1 General . 12
31 6.2.2 Material and mechanical strength . 13
32 6.2.3 Interior chamber . 13
33 6.2.4 Exterior chamber . 13
34 6.2.5 Gap adjustment . 13
35 6.2.6 Injection of mixture . 13
36 6.2.7 Position of ignition source. 13
37 6.3 Procedure . 13
38 6.3.1 Preparation of gas mixtures . 13
39 6.3.2 Temperature and pressure . 13
40 6.3.3 Gap adjustment . 13
41 6.3.4 Ignition . 14
42 6.3.5 Observation of the ignition process . 14
43 6.4 Determination of maximum experimental safe gap (MESG) . 14
44 6.4.1 General . 14
45 6.4.2 Preliminary tests . 14
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46 6.4.3 Confirmatory tests . 14
47 6.4.4 Reproducibility of maximum experimental safe gaps (MESG) . 14
48 6.4.5 Tabulated values . 14
49 6.5 Verification of the MESG determination method . 14
50 7 Method of test for auto-ignition temperature (AIT) . 15
51 7.1 Outline of method . 15
52 7.2 Apparatus . 15
53 7.2.1 General . 15
54 7.2.2 Test vessel and support . 16
55 Thermocouples . 16
7.2.3
56 7.2.4 Oven . 16
57 7.2.5 Metering devices . 17
58 7.2.6 Mirror . 17
59 7.2.7 Timer . 17
60 7.2.8 Equipment for purging the test vessel with air . 17
61 Automated apparatus . 17
7.2.9
62 7.3 Sampling, preparation and preservation of test samples . 17
63 7.3.1 Sampling . 17
64 7.3.2 Preparation and preservation . 17
65 7.4 Procedure . 18
66 7.4.1 General . 18
67 Sample injection . 18
7.4.2
68 7.4.3 Determination of the auto ignition temperature (AIT) . 19
69 7.5 Auto-ignition temperature (AIT) . 20
70 7.6 Validity of results . 20
71 7.6.1 Repeatability . 20
72 7.6.2 Reproducibility . 20
73 Data . 20
7.7
74 7.8 Verification of the auto-ignition temperature determination method . 20
75 Annex A (normative) Ovens of test apparatus for the tests of auto-ignition
76 temperature . 22
77 “IEC oven” . 22
A.1
78 A.2 “DIN oven” . 22
79 Annex B (informative) Tabulated values . 30
80 Annex C (informative) Determination of cool flames . 78
81 Annex D (informative) Volume dependence of auto ignition temperature . 79
82 Bibliography . 80
83
84 Figure 1 – Test apparatus . 12
85
Figure A.1 – Test apparatus: assembly . 23
86 Figure A.2 – Section A-A (flask omitted) . 24
87
Figure A.3 – Base heater (board made of refractory material) . 24
88 Figure A.4 – Flask guide ring (board made of refractory material) . 25
89
Figure A.5 – Neck heater (board made of refractory material) . 26
90 Figure A.6 – Oven . 27
91
Figure A.7 – Lid of steel cylinder . 28
92 Figure A.8 – Lid of steel cylinder . 29
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93 Figure A.9 – Injection of gaseous sample . 29
94 Figure C.1 – Additional thermocouple to detect cool flames . 78
95 Figure C.2 – ‘Negative temperature coefficient’ shown for butyl butyrate as an example . 78
96 Figure D.1 – Volume dependence of auto ignition temperature . 79
97
98 Table 1 – Classification of temperature class and range of auto-ignition temperatures . 11
99 Table 2 – Values for verification of the apparatus . 15
100 Table 3 – Values for verification of the apparatus . 20
101
102
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103 INTERNATIONAL ELECTROTECHNICAL COMMISSION
104 ____________
105
106 EXPLOSIVE ATMOSPHERES –
107
108 Part 20-1: Material characteristics for gas
109 and vapour classification –
110 Test methods and data
111
112
113 FOREWORD
114 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
115 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
116 international co-operation on all questions concerning standardization in the electrical and electronic fields. To
117 this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
118 Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
119 Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
120 in the subject dealt with may participate in this preparatory work. International, governmental and non-
121 governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
122 with the International Organization for Standardization (ISO) in accordance with conditions determined by
123 agreement between the two organizations.
124 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
125 consensus of opinion on the relevant subjects since each technical committee has representation from all
126 interested IEC National Committees.
127 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
128 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
129 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
130 misinterpretation by any end user.
131 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
132 transparently to the maximum extent possible in their national and regional publications. Any divergence
133 between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
134 the latter.
135 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
136 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
137 services carried out by independent certification bodies.
138 6) All users should ensure that they have the latest edition of this publication.
139 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
140 members of its technical committees and IEC National Committees for any personal injury, property damage or
141 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
142 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
143 Publications.
144 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
145 indispensable for the correct application of this publication.
146 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
147 patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
148 International Standard IEC 80079-20-1 has been prepared by IEC technical committee
149 SC31M: Non-electrical equipment and protective systems for explosive atmospheres.
150 This first edition of ISO/IEC 80079-20-1 cancels and replaces the first edition of IEC 60079-
151 20-1(2010). It constitutes a technical revision. No significant changes with respect to the other
152 edition were done.
153
154
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155 It is published as a double logo standard.
156 The text of this standard is based on the following documents:
FDIS Report on voting
31M/xxx/xxx 31M/xxx/xxx
157
158 Full information on the voting for the approval of this standard can be found in the report on
159 voting indicated in the above table.In ISO, the standard has been approved by xx P members
160 out of xx having cast a vote.
161 This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
162 A list of all parts of the IEC 60079 respectively ISO/IEC 80079 series, under the general title:
163 Explosives atmospheres can be found on the IEC website.
164 The committee has decided that the contents of this publication will remain unchanged until
165 the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
166 related to the specific publication. At this date, the publication will be
167 • reconfirmed,
168 • withdrawn,
169 • replaced by a revised edition, or
170 • amended.
171
172 The National Committees are requested to note that for this publication the stability date
173 is 2020
174 THIS TEXT IS INCLUDED FOR THE INFORMATION OF THE NATIONAL COMMITTEES AND WILL BE
175 DELETED AT THE PUBLICATION STAGE.
176
177
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178 EXPLOSIVE ATMOSPHERES –
179
180 Part 20-1: Material characteristics for gas
181 and vapour classification –
182 Test methods and data
183
184
185
186 1 Scope
187 This part of ISO/IEC 80079 provides guidance on classification of gases and vapours. It
188 describes a test method intended for the measurement of the maximum experimental safe
189 gaps (MESG) for gas-air mixtures or vapour-air mixtures under normal conditions of
1
190 temperature and pressure (20 °C, 100 kPa) so as to permit the selection of an appropriate
191 group of equipment. The standard describes also a test method intended for use in the
192 determination of the auto-ignition temperature (AIT) of a vapour-air mixture or gas-air mixture
193 at atmospheric pressure, so as to permit the selection of an appropriate temperature class of
194 equipment.
195 Values of chemical properties of materials are provided to assist in the selection of equipment
196 to be used in hazardous areas. Further data may be added as the results of validated tests
197 become available.
198 The materials and the characteristics included in a table (see Annex B) have been selected
199 with particular reference to the use of equipment in hazardous areas. The data in this
200 standard have been taken from a number of references which are given in the bibliography.
201 These methods for determining the MESG or the AIT may also be used for gas-air-inert
202 mixtures or vapour-air-inert mixtures. However, data on air-inert mixtures are not tabulated.
203 2 Normative references
204 The following referenced documents are indispensable for the application of this document.
205 For dated references, only the edition cited applies. For undated references, the latest edition
206 of the referenced document (including any amendments) applies.
207 IEC 60079-11, Explosive atmospheres – Part 11: Equipment protection by intrinsic safety "i"
208 IEC 60079-14, Explosive atmospheres – Part 14: Electrical installations design, selection and
209 erection
210 3 Terms and definitions
211 For the purposes of this document, the following terms and definitions apply.
212 Note 1 to entry: For the definitions of any other terms, particularly those of a more general nature, reference should
213 be made to IEC 60050-426 or other appropriate parts of the IEV (International Electrotechnical Vocabulary).
214 3.1
215 ignition by hot surface (auto-ignition)
216 a reaction which is evidenced by a clearly perceptible flame and/or explosion, and for which
217 the ignition delay time does not exceed 5 min
218
219 Note 1 to entry: See 7.2.2 for a test method
—————————
1 An exception is made for substances with vapour pressures which are too low to permit mixtures of the required
concentrations to be prepared at normal ambient temperatures. For these substances, a temperature 5 K above that
needed to give the necessary vapour pressure or 50 K above the flash point is used.
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220 3.2
221 ignition delay time
222 time between the completed injection of the flammable material and the ignition
223 3.3
224 auto-ignition temperature
225 AIT
226 lowest temperature (of a hot surface) at which under specified test conditions an ignition of a
227 flammable gas or vapour in mixture with air or air-inert gas occurs
228 Note 1 to entry: See Clause 7 for a test method.
229 3.4
230 maximum experimental safe gap
231 MESG
232 maximum gap of a joint of 25 mm in width which prevents any transmission of an explosion
233 during the tests made under specified conditions
234 Note 1 to entry: See Clause 6 for a test method.
235 3.5
236 minimum igniting current
237 MIC
238 minimum current in a specified test circuit that causes the ignition of the explosive test mixture
239 in the spark-test apparatus according to IEC 60079-11
240 Note 1 to entry: See 5.1.6 for the test circuit.
241 3.6
242 flammable limits
243 the flammable limits of a gas or vapor are the lower (LFL) and upper (UFL) flammable limit, stated in
244 percent by volume or in g/m³ of gas in a gas-air mixture, between which a flammable mixture is formed
245 Note 1 to entry: In the past, flammable and explosive have been used interchangeably in many texts, but the trend
246 is to avoid the confusion that this causes. The term flammable relates to the properties of the material that
247 determine its ability to produce self-sustaining flame propagation in any direction (upwards, sideways or
248 downwards). The term explosive relates to flame propagation that is accompanied by pressure and temperature
249 rise and noise (usually higher-speed propagation) and is significantly affected by (non-material related) test-
250 chamber conditions (geometry, degree of confinement…). LFL concentrations are typically lower than LEL
251 concentrations for the same material and UFL concentrations are typically higher than UEL concentrations for the
252 same material.
253 3.7
254 equipment grouping
255 classification system of equipment related to the explosive atmosphere for which they are intended to
256 be used
257 Note 1 to entry: IEC 60079-0 identifies three equipment groups:
258 Group I, equipment for mines susceptible to fire damp;
259 Group II, which is divided into sub-groups, equipment for all places with an explosive gas atmosphere
260 other than mines susceptible to fire damp
261 Group III, which is divided into sub-groups, equipment for all places with an explosive dust atmosphere
262 other than mines susceptible to fire damp
263 3.8
264 flash point
265 FP
266 lowest liquid temperature at which, under specified test conditions, a liquid gives off vapours in
267 quantity such as to be capable of forming an ignitable vapour-air mixture
268 3.9
269 gas
270 gaseous phase of a substance that cannot reach equilibrium with its liquid or solid state in the
271 temperature and pressure range of interest
272 Note 1 to entry: This is a simplification of the scientific definition, and merely requires that the substance is above
273 its boiling point or sublimation point at the ambient temperature and pressure.
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274 3.10
275 vapour
276 gaseous phase of a substance that can reach equilibrium with its liquid or solid state in the
277 temperature and pressure range of interest
278 Note 1 to entry: This is a simplification of the scientific definition, and merely requires that the substance is below
279 its boiling point or sublimation point at the ambient temperature and pressure.
280 4 Classification of gases and vapours
281 4.1 General
282 Group I addresses mines susceptible to firedamp.
283 Note Firedamp consists mainly of methane, but always contains small quantities of other gases, such as nitrogen,
284 carbon dioxide, and hydrogen, and sometimes ethane and carbon monoxide. The terms firedamp and methane are
285 used frequently in mining practice as synonyms.
286 Group II addresses flammable gases and vapours other than in mines susceptible to
287 firedamp. Group II gases and vapours are classified according to their MESG and/or MIC ratio
288 into subgroups.
289 All flammable materials are classified according to their AIT into temperature classes.
290 4.2 Classification according to the maximum experimental safe gaps (MESG)
291 Gases and vapours may be classified according to their MESG into Groups IIA, IIB or IIC,
292 based on the determination method described in this standard. This method does not take into
2
293 account the possible effects of obstacles on the safe gaps .
294 NOTE 1 The standard method for determining MESG is described in 6.2, but where determinations have been
295 undertaken only in an 8 l spherical vessel with ignition close to the flange gap these can be accepted provisionally.
296 For the purpose of classification the MESG limits are:
297 Group IIA: MESG ≥ 0,90 mm.
298 Group IIB: 0,50 mm < MESG < 0,90 mm.
299 Group IIC: MESG ≤ 0,50 mm.
300 Determination of both the MESG and MIC ratio is required when 0,50 < MESG < 0,55. Then
301 the Group is determined by MIC ratio,
302 NOTE 2 For gases and highly volatile liquids, the MESG is determined at 20 °C.
303 NOTE 3 If it was necessary to do the MESG determination at temperatures higher than ambient temperature a
304 temperature 5 K above that needed to give the necessary vapour pressure or 50 K above the flash point is used
305 and this value of MESG is given in the table
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