EN ISO 80079-37:2016

SLOVENSKI STANDARD
01-julij-2016
1DGRPHãþD
SIST EN 13463-5:2011
SIST EN 13463-6:2005
SIST EN 13463-8:2003
(NVSOR]LYQHDWPRVIHUHGHO1HHOHNWULþQDRSUHPD]DXSRUDERYSRWHQFLDOQR
HNVSOR]LYQLKDWPRVIHUDK1HHOHNWULþQDYUVWD]DãþLWHVNRQVWUXNFLMVNRYDUQRVWMR
FNRQWURORYLURYYåLJDEVSRWRSLWYLMRYWHNRþLQRN,62
Explosive atmospheres - Part 37: Non-electrical equipment for use in explosive
atmospheres - Non-electrical type of protection constructional safety 'c', control of ignition
sources 'b', liquid immersion 'k' (ISO 80079-37:2016)
Explosionsfähige Atmosphären - Nicht-elektrische Geräte für den Einsatz in
explosionsfähigen Atmosphären - Teil 37: Sicherheit 'c', Zündquellenüberwachung 'b',
Flüssigkeitskapselung 'k' (ISO 80079-37:2016)
Atmosphères explosives - Partie 37: Matériels non électriques pour atmosphères
explosives - Mode de protection non électrique par sécurité de construction "ch", par
contrôle de source d'inflammation "bh", par immersion dans un liquide "kh" (ISO/DIS
80079-37:2016)
Ta slovenski standard je istoveten z: EN ISO 80079-37:2016
ICS:
13.230 Varstvo pred eksplozijo Explosion protection
29.260.20 (OHNWULþQLDSDUDWL]D Electrical apparatus for
HNVSOR]LYQDR]UDþMD explosive atmospheres
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 80079-37
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2016
EUROPÄISCHE NORM
ICS 29.260.20 Supersedes EN 13463-5:2011, EN 13463-6:2005, EN
13463-8:2003
English Version
Explosive atmospheres - Part 37: Non-electrical equipment
for explosive atmospheres - Non-electrical type of
protection constructional safety ''c'', control of ignition
sources ''b'', liquid immersion ''k'' (ISO 80079-37:2016)
Atmosphères explosives - Partie 37: Appareils non Explosionsgefährdete Bereiche - Teil 37: Nicht-
électriques destinés à être utilisés en atmosphères elektrische Geräte für den Einsatz in
explosives - Mode de protection non électrique par explosionsgefährdeten Bereichen - Schutz durch
sécurité de construction "c", par contrôle de la source konstruktive Sicherheit 'c', Zündquellenüberwachung
d'inflammation "b", par immersion dans un liquide "k" 'b', Flüssigkeitskapselung 'k' (ISO 80079-37:2016)
(ISO 80079-37:2016)
This European Standard was approved by CEN on 8 February 2016.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 80079-37:2016 E
worldwide for CEN national Members.

Contents Page
European Foreword . 3
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/34/EU . 4
Annex ZB (informative) Significant changes between this European Standard and
EN 13463-5:2011, EN 13463-6:2005 and EN 13463-8:2003 . 6

European Foreword
This document (EN ISO 80079-37:2016) has been prepared by Technical Committee ISO/TMBG
"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 October 2016, and conflicting national standards shall
be withdrawn at the latest by October 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
The significant changes with respect to EN 13463-5:2011, EN 13463-6:2005 and EN 13463-8:2003 are
included in Annex ZB “Significant changes between this European Standard and EN 13463-5:2011,
EN 13463-6:2005 and EN 13463-8:2003".
This document supersedes EN 13463-5:2011, EN 13463-6:2005, EN 13463-8:2003.
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 2014/34/EU.
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this
document.
Extensions to the marking scheme described in the Directive are found in the ATEX Guidelines
published by the European Commission. These are particularly useful for equipment that conforms to
more than one category.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 80079-37:2016 has been approved by CEN as EN ISO 80079-37:2016 without any
modification.
Annex ZA
(informative)
Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/34/EU
This European Standard has been prepared under a mandate given to CEN by the European
Commission and the European Free Trade Association to provide a means of conforming to Essential
Requirements of the New Approach Directive 2014/34/EU.
Once this standard is cited in the Official Journal of the European Union under that Directive and has
been implemented as a national standard in at least one Member State, compliance with the 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 94/9/EC
Clause(s)/sub- Essential Requirements Qualifying remarks/Notes
clause(s) of this EN (ERs) of 2014/34 EU
4 1.1.1
1.1.3
5.1 1.3.4 See also 80079-36
1.4.1 Clause has some limited relevance to ESR
1.2.4
5.2 1.1.1
5.3.1 1.3.1 See also 80079-36
5.3.2 1.2.3 See also 80079-36
5.4 1.3.1 See also 80079-36
5.6.1 1.0.6a Not much additional information
1.1.3
5.6.2 1.3.4 See also 80079-36
5.6.3 1.3.1 See also 80079-36
5.7.1 1.0.6a
1.0.6c
1.2.1
5.7.2 1.3.1 See also 80079-36
5.7.3 1.1.3
5.8.1 1.1.3 See also 80079-36
1.3.1 Limited information in respect of 1.1.3
1.3.4
5.8.2.1 1.3.1 See also 80079-36
5.8.2.2 1.3.1 See also 80079-36
Clause(s)/sub- Essential Requirements Qualifying remarks/Notes
clause(s) of this EN (ERs) of 2014/34 EU
1.3.2
5.8.2.3 1.3.4 See also 80079-36
5.8.2.4 1.3.4 See also 80079-36
5.8.5.1 1.3.4 See also 80079-36
5.9.3 1.3.4 See also 80079-36
6.1 1.3.1 See also 80079-36
6.2 1.0.6a See also 80079-36
1.1.3 Clause has some limited relevance to ESR
1.2.4
1.2.1
1.3.4
1.4.1
6.3 1.0.6a
1.2.1
6.4 1.0.6a
1.2.1
6.5 1.0.6a
1.2.1
7.1 1.0.6a See also 80079-36
1.2.1 Clause has some limited relevance to ESR
1.2.4
1.3.2
1.3.4
1.4.1
7.2 1.0.6a
1.2.1
7.3 1.0.6a
1.1.3
1.2.1
7.3.3 1.3.1
7.3.4 1.2.3 See also 80079-36
1.3.2
WARNING — Other requirements and other EU Directives may be applicable to the product(s) falling
within the scope of this standard.
Annex ZB
(informative)
Significant changes between this European Standard and EN 13463-5:2011,
EN 13463-6:2005 and EN 13463-8:2003
This European Standard supersedes EN 13463-5:2011, EN 13463-6:2005 and EN 13463-8:2003.
Table ZB.1 — Significant changes between this European Standard and EN 13463-5:2011,
EN 13463-6:2005 and EN 13463-8:2003
Clauses of this European Standard Type
Minor and Substantial
formal Extension change
changes regarding ESRs
Introduction of new definitions and slight
redefinitions concerning ignition sources to
improve ignition hazard assessment
Clause 3 X X
(EN 13463-5, EN 13463-6, EN 13463-8
Clause 3)
Differentiation in requirements for ingress
prevention for dust and liquids (EN 13463-5, 5.2.2 X
Clause 4.3.4)
Changing note to normative text (EN 13463-5,
5.3.3 X X
Clause 4.4.3)
Note 2 deleted and moved to 5.6 (EN 13463-5,
5.5 X
Clause 4.6)
nd
Additional requirement listed (2 clause)
5.6 X X
(from EN 13463-5, Clause 4.6)
Additional measure listed (EN 13463-5,
5.6.3 X X
Clause 5.3)
Changing of wording regarding information
5.7.1 X
for instructions (EN 13463-5, Clause 6.1)
Changing of wording regarding information
5.7.2 X
for instructions (EN 13463-5, Clause 6.2)
Additional requirement New reference
regarding electrostatic requirements
5.8.2.2 X
(EN 13463-5, note in 7.2.2)
New note
Changing of wording (EN 13463-5,
5.8.2.5 X
Clause 7.6.5)
Changing to clarify dependency of
requirements
5.10 X
(EN 13463-5, Clause 7.3.2)
Differentiation to clarify dependency of 5.11.1 X X
Clauses of this European Standard Type
Minor and Substantial
formal Extension change
changes regarding ESRs
requirements (EN 13463-5, Clause 8.1)
Additional requirement (EN 13463-5,
5.13.3 X
Clause 10.3)
Editorial modification for clarification
Clause 6 X X
(EN 13463-6, Clause 6.1)
Editorial modification for clarification
7.1 X
(EN 13463-8, Clause 5.1)
Editorial modification for clarification
7.3.2 X
(EN 13463-8, Clause 7.2)
Additional example (EN 13463-8, Clause 7.4) 7.3.4 X
Editorial modification for clarification
7.3.6 X
(EN 13463-8, Clause 7.8)
Introduction of new definitions for marking Clause 10 X X

NOTE 1 The technical changes referred include the significant technical changes from the EN revised but is not
an exhaustive list of all modifications from the previous version.
Explanations:
A) Definitions
Minor and editorial changes clarification
decrease of technical requirements
minor technical change
editorial corrections
Changes in a standard classified as ‘Minor and editorial changes’ refer to changes regarding the
previous standard, which modify requirements in an editorial or a minor technical way. Also changes of
the wording to clarify technical requirements without any technical change are classified as ‘Minor and
editorial changes’.
A reduction in level of existing requirement is also classified as ‘Minor and editorial changes’
Extension addition of technical options

Changes in a standard classified as ‘extension’ refers to changes regarding the previous standard, which
add new or modify existing technical requirements, in a way that new options are given, but without
increasing requirements for equipment that was fully compliant with the previous standard. Therefore
these ‘extensions’ will not have to be considered for products in conformity with the preceding edition.
Major technical changes addition of technical requirements
increase of technical requirements

Changes in a standard classified as ‘Major technical change’ refer to changes regarding the previous
standard, which add new or increase the level of existing technical requirements, in a way that a
product in conformity with the preceding standard will not always be able to fulfil the requirements
given in the standard. ‘Major technical changes’ have to be considered for products in conformity with
the preceding edition. For every change classified as ‘Major Technical Change’ additional information is
provided in clause B) of the Annex ZB.
NOTE 2 These changes represent current technological knowledge . However, these changes should not
normally have an influence on equipment already placed on the market.
B) Information about the background of ‘Major Technical Changes’
None
see also ATEX Guide 10.3 and Annex ZA.
ISO 80079-37
Edition 1.0 2016-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 37: Non-electrical equipment for explosive atmospheres – Non electrical

type of protection constructional safety “c”, control of ignition source “b”, liquid

immersion “k”
Atmosphères explosives –
Partie 37: Appareils non électriques destinés à être utilisés en atmosphères

explosives – Mode de protection non électrique par sécurité de construction "c",

par contrôle de la source d'inflammation "b", par immersion dans un liquide "k"

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.230; 29.260.20 ISBN 978-2-8322-3181-4

– 2 – ISO 80079-37:2016 © ISO 2016
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references. 7
3 Terms and definitions . 8
4 Determination of suitability . 9
5 Requirements for equipment with Type of Protection constructional safety “c” . 9
5.1 General requirements . 9
5.2 Ingress protection . 10
5.2.1 General . 10
5.2.2 Ingress protection in special cases . 10
5.3 Seals for moving parts . 10
5.3.1 Unlubricated gaskets, seals, sleeves, bellows and diaphragms . 10
5.3.2 Stuffing box seals (packed glands) . 11
5.3.3 Lubricated seals . 11
5.4 Equipment lubricants, coolants and fluids . 11
5.5 Vibration . 11
5.6 Requirements for moving parts . 11
5.6.1 General . 11
5.6.2 Clearance . 12
5.6.3 Lubrication . 12
5.7 Requirements for bearings . 12
5.7.1 General . 12
5.7.2 Lubrication . 13
5.7.3 Chemical compatibility . 13
5.8 Requirements for power transmission systems . 14
5.8.1 Gear drives . 14
5.8.2 Belt drives . 14
5.8.3 Chain drives. 15
5.8.4 Other drives . 15
5.8.5 Hydrostatic, hydrokinetic and pneumatic equipment . 15
5.9 Requirements for clutches and variable speed couplings . 16
5.9.1 General . 16
5.9.2 Slipping . 16
5.9.3 Friction . 17
5.10 Flexible couplings . 17
5.11 Requirements for brakes and braking systems . 17
5.11.1 Brakes used only for stopping in emergency . 17
5.11.2 Service brakes (including friction brakes and fluid based retarders) . 18
5.11.3 Parking brakes . 18
5.12 Requirements for springs and absorbing elements . 18
5.13 Requirements for conveyor belts . 18
5.13.1 Electrostatic requirements . 18
5.13.2 Materials . 18
5.13.3 Belt tension . 18
5.13.4 Alignment . 19
5.13.5 Earthing and bonding . 19

ISO 80079-37:2016 © ISO 2016 – 3 –
6 Requirements for equipment with Type of Protection control of ignition source “b” . 19
6.1 General . 19
6.2 Determination of the control parameters . 19
6.2.1 General . 19
6.2.2 Determination of the safety critical values . 20
6.3 Ignition prevention system design and settings . 20
6.3.1 Determining the performance requirements or operating characteristics . 20
6.3.2 Instructions . 20
6.3.3 System lockout . 20
6.3.4 Operator intervention . 21
6.4 Ignition protection of sensors and actuators . 21
6.5 Ignition protection types . 21
6.5.1 Ignition protection type b1 . 21
6.5.2 Ignition protection type b2 . 21
6.5.3 Application of ignition protection types . 22
6.5.4 Requirements for ignition protection types . 23
6.5.5 Programmable electronic devices . 23
7 Requirements for equipment with Type of Protection liquid immersion “k”. 23
7.1 Determination of the maximum / minimum criteria . 23
7.2 Protective liquid . 24
7.3 Equipment construction . 24
7.3.1 General . 24
7.3.2 Working angle . 24
7.3.3 Measures to ensure effectiveness of liquid . 24
7.3.4 Accidental loosening . 25
7.3.5 Level monitoring . 25
7.3.6 Loss of liquid . 25
7.3.7 Open equipment . 26
8 Type tests . 26
8.1 Type tests for equipment with Type of Protection constructional safety “c” . 26
8.2 Type tests for equipment with Type of Protection control of ignition source
“b” . 26
8.2.1 Determination of control parameters . 26
8.2.2 Function and accuracy check of the ignition protection system . 26
8.3 Type tests for equipment with Type of Protection liquid immersion “k” . 26
8.3.1 General . 26
8.3.2 Increased pressure test on enclosed equipment having a sealed
enclosure that contains static, or flowing protective liquid . 26
8.3.3 Overpressure test on enclosed equipment having a vented enclosure . 26
9 Documentation . 26
9.1 Documentation for equipment with Type of Protection constructional safety
“c” . 26
9.2 Documentation for equipment with Type of Protection control of ignition
sources “”b” . 27
9.3 Documentation for equipment with Type of Protection liquid immersion “k” . 27
10 Marking . 28
10.1 General . 28
10.2 Safety devices . 28

– 4 – ISO 80079-37:2016 © ISO 2016
Annex A (informative) Approach and application: equipment with Type of
Protection “c” . 29
A.1 General remarks regarding ignition hazard assessment . 29
A.2 Stuffing box seal (see Table A.2) . 29
A.3 Slide ring seal . 31
A.4 Radial seal . 36
A.5 Belt drives . 40
Annex B (normative) Test requirements . 42
B.1 "Dry run" type test for lubricated sealing arrangements . 42
B.2 Type test for determining the maximum engaging time of clutch assembly . 42
B.2.1 Apparatus . 42
B.2.2 Procedure . 43
Annex C (informative) Methodology: equipment with Type of Protection “b” . 44
Annex D (informative) Approach to assign the required ignition protection type used
for equipment to achieve different EPL . 45
D.1 For EPL Gc and Dc . 45
D.2 For EPL Gb and Db . 45
D.3 For EPL Mb . 45
D.4 For EPL Ga and Da . 46
Annex E (informative) Information on functional safety concept . 47
E.1 ISO 13849-1 . 47
E.2 IEC 61508-1 . 47
E.3 IEC 62061 . 47
E.4 Reliability according to functional safety standards . 47
Bibliography . 49

Figure C.1 – Flow diagram of the procedures described in this document . 44

Table 1 – Minimum ignition protection types required when Ex “b” is selected to
achieve the intended EPL for Group II and III equipment. 22
Table 2 – Minimum ignition protection types required when Ex “b” is selected to
achieve the intended EPL for Group I equipment . 23
Table A.1 – List of examples for some of the thought processes and principles used . 29
Table A.2 – Stuffing box seal . 30
Table A.3 – Slide ring seal . 32
Table A.4 – Radial seal . 37
Table A.5 – Belt drives . 41
Table E.1 – Application of ignition protection type . 48

ISO 80079-37:2016 © ISO 2016 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHÈRES –
Part 37: Non-electrical equipment for explosive atmospheres –
Non electrical type of protection constructional safety “c”,
control of ignition source “b”, liquid immersion “k”

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 80079-37 has been prepared by IEC sub-committee 31M: Non-
electrical equipment and protective systems for explosive atmospheres, of IEC 31: Equipment
for explosive atmospheres.
The text of this standard is based on the following documents of the IEC:
FDIS Report on voting
31M/104/FDIS 31M/110/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. In ISO, the standard has been approved by 15 P members
out of 20 having cast a vote.
– 6 – ISO 80079-37:2016 © ISO 2016
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 web site 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.
.
ISO 80079-37:2016 © ISO 2016 – 7 –
EXPLOSIVE ATMOSPHERES –
Part 37: Non-electrical equipment for explosive atmospheres –
Non electrical type of protection constructional safety “c”,
control of ignition source “b”, liquid immersion “k”

1 Scope
This part of ISO/IEC 80079 specifies the requirements for the design and construction of non-
electrical equipment, intended for use in explosive atmospheres, protected by the types of
protection constructional safety “c”, control of ignition source “b” and liquid immersion “k”.
This part of ISO/IEC 80079 supplements and modifies the requirements in ISO 80079-36.
Where a requirement of this standard conflicts with the requirement of ISO 80079-36 the
requirement of this standard takes precedence.
Types of Protection “c”, “k” and “b” are not applicable for Group I, EPL Ma without additional
protective precautions.
The types of ignition protection described in the standard can be used either on their own or
in combination with each other to meet the requirements for equipment of Group I, Group II,
and Group III depending on the ignition hazard assessment in ISO 80079-36.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements
IEC TS 60079-32-1, Explosive atmospheres – Part 32-1: Electrostatic hazards, Guidance
IEC 60529, Degrees of protection provided by enclosures (IP Code)
ISO 281, Rolling bearings – Dynamic load ratings and rating life
ISO 1813, Belt drives – V-ribbed belts, joined V-belts and V-belts including wide section belts
and hexagonal belts – Electrical conductivity of antistatic belts: Characteristics and methods
of test
ISO 9563, Belt drives – Electrical conductivity of antistatic endless synchronous belts –
Characteristics and test method
ISO 4413, Hydraulic fluid power – General rules and safety requirements for systems and
their components
ISO 4414, Pneumatic fluid power – General rules and safety requirements for systems and
their components
ISO 19353, Safety of machinery – Fire prevention and protection

– 8 – ISO 80079-37:2016 © ISO 2016
ISO 80079-36: 2016, Explosive atmospheres – Non-electrical equipment for explosive
atmospheres – Part 1: Basic method and requirements
EN 13237, Potentially explosive atmospheres – Terms and definitions for equipment and
protective systems intended for use in potentially explosive atmospheres
EN 13501-1, Fire classification of construction products and building elements – Part 1:
Classification using data from reaction to fire tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 80079-36,
IEC 60079-0 and the following apply.
3.1
constructional safety “c”
ignition protection where constructional measures are applied so as to protect against the
possibility of ignition from hot surfaces, sparks and adiabatic compression generated by
moving parts
3.2
mechanically generated sparks
sparks produced by mechanical impact or friction burning particles, as well as showers of
particles, produced by impact or friction between two solid materials
3.3
control of ignition source “b”
ignition protection where mechanical or electrical devices are used in conjunction with non-
electrical equipment to manually or automatically reduce the likelihood of a potential ignition
source from becoming an effective ignition source
Note 1 to entry: This might for example be a level sensor used to indicate loss of oil, a temperature sensor to
indicate a hot bearing or a speed sensor to indicate over-speed.
3.3.1
automatic control measure
action taken without manual intervention, to reduce the likelihood of a potential ignition source
from becoming an effective ignition source
3.3.2
manual control measure
action taken by a person as a result of a warning, indication, or alarm, to reduce the likelihood
of a potential ignition source from becoming an effective ignition source
3.3.3
ignition prevention devices/systems
arrangement that converts signals from one or more sensors into an action, or indication, to
reduce the likelihood of a potential ignition source from becoming an effective ignition source
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To be published.
ISO 80079-37:2016 © ISO 2016 – 9 –
3.3.4
safety devices
devices intended for use inside or outside explosive atmospheres but required for or
contributing to the safe functioning of equipment and protective systems with respect to the
risks of explosion
3.4
liquid immersion “k”
type of protection where potential ignition sources are made ineffective or separated from the
explosive atmosphere by either totally immersing them in a protective liquid, or by partially
immersing and continuously coating their active surfaces with a protective liquid in such a way
that an explosive atmosphere which may be above the liquid, or outside the equipment
enclosure, cannot be ignited
3.4.1
protective liquid
a liquid which prevents the explosive atmosphere from making direct contact with potential
ignition sources and thereby ensures the explosive atmosphere cannot be ignited
3.4.2
equipment with a sealed enclosure
totally enclosed equipment that limits the ingress of an external atmosphere during the
expansion and contraction of the internally contained protective liquid during use in service
Note 1 to entry: Such equipment includes any pipework associated with it and often contains an overpressure
relief device.
3.4.3
equipment with a vented enclosure
enclosed equipment that allows the ingress and egress of an external atmosphere through a
breathing device or constricted opening during the expansion and contraction of the internally
contained protective fluid during normal operation
Note 1 to entry: Such equipment includes any pipework associated with it.
3.4.4
open equipment
equipment that is immersed, or has its components immersed, in a protective liquid that is
open to the external atmosphere
Note 1 to entry: For example, an open top vessel with immersed moving components. Such equipment includes
any pipework associated with it.
4 Determination of suitability
Before a decision is made to protect equipment or parts of equipment for use as an assembly,
including interconnecting parts, by the measures described in this standard, it shall have been
subjected to the ignition hazard assessment in accordance with ISO 80079-36.
5 Requirements for equipment with Type of Protection constructional safety
“c”
5.1 General requirements
Equipment designed and constructed according to the applicable safety requirements of the
relevant industrial standards is intended to be capable of functioning in conformity with the
operational parameters established by the manufacturer, including any mechanical and
thermal stresses that they are intended to be subjected to.

– 10 – ISO 80079-37:2016 © ISO 2016
This also applies to interconnecting parts of equipment including joints (e.g. cemented,
soldered, or welded joints).
NOTE This is accomplished by using one or more of the following documents:
• International standards or Technical Specifications
• FDIS of International standards or Technical Specifications
• National Standards or Technical Specifications
• Technical specifications or Test Reports issued by an Ex accredited Test Laboratory
• Technical specifications of industrial associations.
5.2 Ingress protection
5.2.1 General
The degree of ingress protection (IP) as specified in IEC 60529 provided by the outer
enclosures of equipment depends upon its intended duty and the type of environment it is
designed to be used in. An appropriate rating shall be determined as part of the ignition
hazard assessment (see Clause 4) and, if relevant for ignition protection, shall be able to
provide that degree of protection.
NOTE IP degrees of protection according to IEC 60529 are not intended to provide protection against the ingress
of an explosive gas atmosphere.
5.2.2 Ingress protection in special cases
The following points specify the minimum IP rating for enclosures used in the circumstances
described.
a) In the case of equipment intended for use in explosive gas atmospheres, where entry of
foreign objects can cause ignition, but entry of dust is harmless, the required degree of
protection against the entry of foreign objects shall be determined in the ignition hazard
assessment and shall be at least IP20.
b) In the case of equipment intended for use in explosive gas atmospheres, where the entry
of dusts or liquids could cau
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