Potentially explosive atmospheres - Terms and definitions for equipment and protective systems intended for use in potentially explosive atmospheres

This European Standard specifies terms and definitions (vocabulary) to be used in suitable standards dealing with equipment and protective systems intended for use in potentially explosive atmospheres.
NOTE   Directive 94/9/EC concerning equipment and protective systems intended for use in potentially explosive atmospheres can be applicable to the type of machine or equipment covered by this European Standard. The present standard is not intended to provide means of complying with the essential health and safety requirements of Directive 94/9/EC.

Explosionsgefährdete Bereiche - Begriffe für Geräte und Schutzsysteme zur Verwendung in explosionsgefährdeten Bereichen

Diese Europäische Norm legt Begriffe für die Anwendung in Normen fest, die sich mit Geräten und Schutzsystemen befassen, die für den Einsatz in explosionsgefährdeten Bereichen bestimmt sind.
ANMERKUNG   Die Richtlinie 94/9/EG über Geräte und Schutzsysteme zur bestimmungsgemäßen Verwendung in explosionsgefährdeten Bereichen kann auf in dieser Norm behandelte Bauarten von Maschinen oder Einrichtungen anwendbar sein. Die vorliegende Norm ist nicht dafür vorgesehen, damit Übereinstimmung mit den grundlegenden Gesundheits- und Sicherheitsanforderungen der Richtlinie 94/9/EG festzustellen.

Atmosphères explosibles - Termes et définitions pour les appareils et systèmes de protection destinés à être utilisés en atmosphères explosibles

La présente Norme européenne spécifie les termes et définitions (vocabulaire) à employer dans les normes spécifiques concernant les appareils et les systèmes de protection destinés à être utilisés en atmosphères explosibles.
NOTE   La Directive 94/9/CE concernant les appareils et les systèmes de protection destinés à être utilisés en atmosphères explosibles peut être applicable au type de machine ou d’appareil couvert par la présente Norme européenne. La présente Norme n'est pas destinée à fournir des mesures pour satisfaire aux exigences essentielles de santé et de sécurité de la Directive 94/9/CE.

Potencialno eksplozivne atmosfere - Izrazi in definicije za opremo in zaščitne sisteme, namenjene za uporabo v potencialno eksplozivnih atmosferah

Ta evropski standard določa izraze in definicije (besedišče), ki se uporabljajo v primernih standardih, ki se ukvarjajo z opremo in zaščitnimi sistemi, namenjenimi za uporabo v potencialno eksplozivnih atmosferah.

General Information

Status
Published
Publication Date
23-Oct-2012
Current Stage
9092 - Decision on results of review/2YR ENQ - revise - Review Enquiry
Due Date
04-Jun-2018
Completion Date
18-Dec-2018

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.DKExplosionsgefährdete Bereiche - Begriffe für Geräte und Schutzsysteme zur Verwendung in explosionsgefährdeten BereichenAtmosphères explosibles - Termes et définitions pour les appareils et systèmes de protection destinés à être utilisés en atmosphères explosiblesPotentially explosive atmospheres - Terms and definitions for equipment and protective systems intended for use in potentially explosive atmospheres13.230Varstvo pred eksplozijoExplosion protection01.040.13Varstvo okolja in zdravja. Varnost (Slovarji)Environment and health protection. Safety (Vocabularies)ICS:Ta slovenski standard je istoveten z:EN 13237:2012SIST EN 13237:2013en01-marec-2013SIST EN 13237:2013SLOVENSKI

STANDARDSIST EN 13237:20031DGRPHãþD
SIST EN 13237:2013
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 13237

October 2012 ICS 01.040.13; 01.040.29; 13.230; 29.260.20 Supersedes EN 13237:2003English Version

Potentially explosive atmospheres - Terms and definitions for equipment and protective systems intended for use in potentially explosive atmospheres

Atmosphères explosibles - Termes et définitions pour les appareils et systèmes de protection destinés à être utilisés en atmosphères explosibles

Explosionsgefährdete Bereiche - Begriffe für Geräte und Schutzsysteme zur Verwendung in explosionsgefährdeten Bereichen This European Standard was approved by CEN on 1 September 2012.

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
Management Centre:
Avenue Marnix 17,

B-1000 Brussels © 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13237:2012: ESIST EN 13237:2013

EN 13237:2012 (E) 2 Contents Page Foreword ..............................................................................................................................................................3Introduction .........................................................................................................................................................41 Scope ......................................................................................................................................................52 Normative references ............................................................................................................................53 Terms and definitions ...........................................................................................................................5Annex A (informative)

Definitions from the Directive 94/9/EC and corrigenda ......................................... 21Annex B (informative)

Significant changes between this European Standard and EN 13237:2003 ........ 24Annex ZA (informative)

Relationship between this European Standard and the Essential Requirements of EU Directive 94/9 EC ............................................................................................. 25Bibliography ..................................................................................................................................................... 26 Figures Figure 1 — Explosion area for a ternary system of test substance, air and inert gas ............................... 9Figure 2 — Relationship between ignition source definitions .................................................................... 16

SIST EN 13237:2013

EN 13237:2012 (E) 3 Foreword This document (EN 13237:2012) has been prepared by 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 2013, and conflicting national standards shall be withdrawn at the latest by April 2013. 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. This document supersedes EN 13237:2003. The significant changes between this European Standard and EN 13237:2003 are given in Annex B. 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 94/9/EC. For relationship with EU Directive 94/9/EC, see informative Annex ZA, which is an integral part of this document. According to the CEN/CENELEC Internal Regulations, the national standards organisations 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. SIST EN 13237:2013

EN 13237:2012 (E) 4 Introduction This European Standard has been produced to assist designers, manufacturers and other interested parties to use harmonised terms and definitions (vocabulary) for equipment and protective systems intended for use in potentially explosive atmospheres. It describes the vocabulary to be used to give all standards in this area an overall uniformity of terminology. Throughout this European Standard, the only hazard considered is the explosion of an explosive atmosphere. SIST EN 13237:2013

EN 13237:2012 (E) 5 1 Scope This European Standard specifies terms and definitions (vocabulary) to be used in suitable standards dealing with equipment and protective systems intended for use in potentially explosive atmospheres. NOTE Directive 94/9/EC concerning equipment and protective systems intended for use in potentially explosive atmospheres can be applicable to the type of machine or equipment covered by this European Standard. The present standard is not intended to provide means of complying with the essential health and safety requirements of Directive 94/9/EC. 2 Normative references Not applicable. 3 Terms and definitions 3.1 ambient atmosphere normal atmosphere surrounding the equipment and protective system 3.2 ambient temperature temperature of the air or other medium where the equipment and protective system are to be used

3.3 combustible dust dust able to undergo an exothermic reaction with air when ignited Note 1 to entry: The terms "flammable" and "combustible" are used synonymously. [SOURCE: EN 14034-1:2004+A1:2011, 3.3] 3.4 conductive dust dust with an electrical resistivity equal to or less than 103 m 3.5 continuous grade of release release which is continuous or is expected to occur frequently or for long periods

[SOURCE: EN 60079-10-1:2009, 3.11] 3.6 deflagration explosion propagating at subsonic velocity

[SOURCE: ISO 8421-1:1987] 3.7 degree of protection extent of protection provided by an enclosure against access to hazardous parts, against ingress of solid foreign objects and/or ingress of water and verified by standardised test methods

[SOURCE: EN 60529:1991 + A1:2000, 3.3] SIST EN 13237:2013

EN 13237:2012 (E) 6 Note 1 to entry: The enclosure which provides the degree of protection IP is not necessarily identical with the types of protection as defined in EN 60079-0. 3.8 detonation explosion propagating at supersonic velocity and characterised by a shock wave

[SOURCE: ISO 8421-1:1987]

3.9 dust small solid particles in the atmosphere which settle out under their own weight, but which may remain suspended in air for some time

[SOURCE: EN 14034-1:2004+A1:2011, 3.1, modified] Note 1 to entry: Generally combustible dusts with a median value below 500 µm may form explosive dust/air-mixtures. 3.10 electrical equipment items applied as a whole or in part for the utilisation of electrical energy

Note 1 to entry: These include, among others, items for the generation, transmission, distribution, storage, measurement, regulation, conversion and consumption of electrical energy and items for telecommunications.

[SOURCE: EN 60079-0:2009, 3.14] 3.11 electrostatic leakage resistance electrical resistance measured between an object and earth [SOURCE: EN 14983:2007, 3.1] 3.12 enclosure (of equipment or protective system) all the walls including doors, covers, cable entries, rods, spindles and shafts which contribute to the type of protection and/or their degree of protection (IP)

3.13 equipment machines, apparatus, fixed or mobile devices, control components and instrumentation thereof and detection or prevention systems which, separately or jointly are intended for the generation, transfer, storage, measurement, control and conversion of energy and/or the processing of material and which are capable of causing an explosion through their own potential ignition source

Note 1 to entry: If equipment supplied to the user contains any interconnecting parts e.g. fastenings, pipes, etc. these form part of the equipment. Note 2 to entry: Simple apparatus with no moving parts, containers and pipes on their own are not considered as equipment under the scope of this European Standard.

[SOURCE: EN 13463-1:2009, 3.1] 3.13.1 equipment Group I category M 1 equipment designed and, where necessary, equipped with additional special means of protection to be capable of functioning in conformity with the operational parameters established by the manufacturer and ensuring a very high level of protection SIST EN 13237:2013

EN 13237:2012 (E) 7 Note 1 to entry: Equipment of this category is intended for use in underground parts of mines as well as those parts of surface installations of such mines endangered by firedamp and/or combustible dust. Note 2 to entry: Equipment of this category is required to remain functional even in the event of rare incidents relating to equipment, with an explosive atmosphere present, and is characterised by means of protection such that:  either, in the event of failure of one means of protection, at least an independent second means provides the requisite level of protection,  or the requisite level of protection is assured in the event of two faults occurring independently of each other. [SOURCE: EN 13463-1:2009, 3.2.1] 3.13.2 equipment Group I category M 2 equipment designed to be capable of functioning in conformity with the operational parameters established by the manufacturer and ensuring a high level of protection Note 1 to entry: Equipment of this category is intended for use in underground parts of mines as well as those parts of surface installations of such mines likely to be endangered by firedamp and/or combustible dust. Note 2 to entry: This equipment is intended to be de-energised in the presence of an explosive atmosphere. Note 3 to entry: The means of protection relating to equipment in this category assure the requisite level of protection during normal operation, expected malfunctions, and also in the case of more severe operating conditions, in particular, those arising from rough handling and changing environmental conditions. [SOURCE: EN 13463-1:2009, 3.2.2, modified] 3.13.3 equipment Group II category 1 equipment designed to be capable of functioning in conformity with the operational parameters established by the manufacturer and ensuring a very high level of protection Note 1 to entry: Equipment in this category is intended for use in areas in which explosive atmospheres caused by mixtures of air and gases, vapours or mists or by air/dust mixtures are present continuously, for long periods or frequently. Note 2 to entry: Equipment of this category ensures the requisite level of protection, even in the event of rare malfunctions relating to equipment, and is characterised by means of protection such that:  either, in the event of failure of one means of protection, at least an independent second means provides the requisite level of protection,  or the requisite level of protection is assured in the event of two faults occurring independently of each other. [SOURCE: EN 13463-1:2009, 3.2.3] 3.13.4 equipment Group II category 2 equipment designed to be capable of functioning in conformity with the operational parameters established by the manufacturer and ensuring a high level of protection Note 1 to entry: Equipment in this category is intended for use in areas in which explosive atmospheres caused by mixtures of air and gases, vapours or mists or by air/dust mixtures are likely to occur. Note 2 to entry: The means of protection relating to equipment in this category ensures the requisite level of protection, even in the event of frequently occurring disturbances or equipment faults which are normally taken into account. [SOURCE: EN 13463-1:2009, 3.2.3] SIST EN 13237:2013

EN 13237:2012 (E) 8 3.13.5 equipment Group II category 3 equipment designed to be capable of functioning in conformity with the operational parameters established by the manufacturer and ensuring a normal level of protection Note 1 to entry: Equipment in this category is intended for use in areas in which explosive atmospheres caused by mixtures of air and gases, vapours or mists or by air/dust mixtures are unlikely to occur or, if they do occur, are likely to do so only infrequently and for a short period only. Note 2 to entry: Equipment of this category ensures the requisite level of protection during normal operation. [SOURCE: EN 13463-1:2009, 3.2.5] 3.14 explosion abrupt oxidation or decomposition reaction producing an increase in temperature, pressure, or in both simultaneously

[SOURCE: ISO 8421-1:1987] 3.15 explosion area area inside the boundary curve formed by the explosion limits of a flammable substance in various mixtures with air and inert gas Note 1 to entry: See Figure 1. Note 2 to entry: In many cases the limiting air concentration corresponds to the apex of the boundary curve. SIST EN 13237:2013

EN 13237:2012 (E) 9

Key 1 explosion area 2 apex 3 stoichiometric line x molar fraction in % IN inert gas TS test substance a air Figure 1 — Explosion area for a ternary system of test substance, air and inert gas 3.16 explosion diverter passive device typically installed in a duct preventing flame jet ignition, pressure piling and reducing the probability of flame transmission into connected equipment [SOURCE: EN 16020:2011, 3.2] 3.17 explosion isolation flap valve flap valve able to stop explosions from propagating through pipelines in the opposing direction to the normal process flow through the valve 3.18 explosion isolation system

3.18.1 active explosion isolation system protective system which is designed to stop explosions from travelling through pipelines or limit the associated destructive effects of the explosion and is activated by detectors and control and indicating equipment (CIE) which are inherent parts of the system SIST EN 13237:2013

EN 13237:2012 (E) 10 [SOURCE: EN 15089:2009, 3.7.1, modified] 3.18.2 passive explosion isolation system protective system which is designed to stop explosions from travelling through pipelines or limit the associated destructive effects of the explosion and does not require detectors and a control and indicating equipment (CIE) [SOURCE: EN 15089:2009, 3.7.2, modified] 3.19 explosion limits

3.19.1 lower explosion limit

LEL lowest concentration of the explosion range at which an explosion can occur Note 1 to entry: Those concentrations are given at which an explosion just fails during the tests (see EN 1839, EN 14034-3). 3.19.2 upper explosion limit

UEL highest concentration of the explosion range at which an explosion can occur Note 1 to entry: Those concentrations are given at which an explosion just fails during the tests (see EN 1839, EN 14034-3). 3.20 explosion points

3.20.1 lower explosion point temperature of a flammable liquid at which the concentration of the saturated vapour in air is equal to the lower explosion limit

3.20.2 upper explosion point temperature of a flammable liquid at which the concentration of the saturated vapour in air is equal to the upper explosion limit

3.21 explosion pressure

pex highest pressure occurring in a closed vessel during the explosion of a specific mixture of flammable substances with air or air and inert gases determined under specified test conditions Note 1 to entry: pex is expressed as absolute pressure with gases and vapour and as overpressure with dusts. [SOURCE: EN 15967:2011, 3.1] 3.21.1 maximum explosion pressure

pmax maximum value of explosion pressure measured in the tests for explosion pressure when the content of the flammable substances in the mixture is varied Note 1 to entry: pmax is expressed as absolute pressure with gases and vapour and as overpressure with dusts. SIST EN 13237:2013

EN 13237:2012 (E) 11 [SOURCE: EN 15967:2011, 3.2] 3.21.2 rate of explosion pressure rise

(dp/dt)ex highest value of the slope (first derivative) of the pressure-time curve (smoothed if necessary), measured in a closed vessel during the explosion of a specific mixture of flammable substances with air or air and inert substances determined under specified test conditions [SOURCE: EN 15967:2011, 3.3] 3.21.3 maximum rate of explosion pressure rise

(dp/dt)max maximum value of the explosion pressure rise per unit time measured in the tests when the content of the flammable substances in the mixture is varied [SOURCE: EN 15967:2011, 3.3, modified] 3.22 explosion range range of the concentration of a flammable substance or mixture of substances in air, within which an explosion can occur, respectively range of the concentration of a flammable substance or mixture of substances in mixture with air/inert gas, within which an explosion can occur, determined under specified test conditions [SOURCE: EN 1839:2012; 3.1] 3.23 explosion resistant property of vessels and equipment designed to be either explosion-pressure-resistant or explosion-pressure-shock resistant 3.23.1 explosion-pressure-resistant property of vessels and equipment designed to withstand the expected explosion pressure without becoming permanently deformed

3.23.2 explosion-pressure-shock resistant property of vessels and equipment designed to withstand the expected explosion pressure without rupturing, but allowing permanent deformation

3.24 explosion suppression technique by which burning in an explosive atmosphere is detected and arrested during incipient stages, restricting development of pressure [SOURCE: EN 14373:2005, 3.10] 3.25 explosion suppression system protective system to detect automatically the onset of an explosion and initiate the deployment of suppressant to limit destructive effects of an explosion and has to be activated by a detector and control and indicating equipment (CIE) which are inherent parts of the system [SOURCE: EN 14373:2005, 3.11, modified] SIST EN 13237:2013

EN 13237:2012 (E) 12 3.26 explosion venting protective measure which will prevent the explosion pressure in a vessel or other closed volume from exceeding the vessel design strength by exhausting the explosion through an explosion venting device in the vessel walls [SOURCE: EN 14797:2006, 3.3] 3.27 explosion venting device device which protects a vessel or other closed volume by explosion venting [SOURCE: EN 14797:2006, 3.4] 3.28 explosive atmosphere mixture with air, under atmospheric conditions, of flammable substances in the form of gases, vapours, mists or dusts, in which, after ignition has occurred, combustion spreads to the entire unburned mixture

[SOURCE: EN 14034-1:2004+A1:2011, 3.4] Note 1 to entry: Close to the explosion limits (LEL and UEL, see 3.19.1 and 3.19.2), the explosion may not necessarily spread to the entire unburned mixture. 3.28.1 hazardous explosive atmosphere explosive atmosphere which causes harm, if it explodes

3.28.2 potentially explosive atmosphere: atmosphere which could become explosive due to local and operational conditions

3.29 extinguishing barrier

active explosion isolation system that is used to discharge suppressant agent into ductwork to isolate a flame and keep it from propagating to other process areas [SOURCE: EN 15089:2009, 3.11, modified] 3.30 flame arrester device fitted to the opening of an enclosure or to the connecting pipework of a system of enclosures and whose intended function is to allow flow, but prevent the transmission of flame

Note 1 to entry: This device should not be confused with a fire barrier, which is ineffective in case of explosion. [SOURCE: EN ISO 16852:2010, 3.1] 3.31 flameless explosion venting explosion venting protective measure which will in addition prevent the transmission of flames and reduce the external explosion effects Note 1 to entry: Examples of external explosion effects are: temperature, pressure and dust/combustion products. [SOURCE: EN 16009:2011, 3.1] SIST EN 13237:2013

EN 13237:2012 (E) 13 3.32 flameless explosion venting device device which protects a vessel or other closed volume by flameless explosion venting [SOURCE: EN 16009:2011, 3.2] 3.33 flameproof enclosure type of protection in which the parts which can ignite an explosive atmosphere are placed in an enclosure which can withstand the pressure developed during an internal explosion of an explosive mixture and which prevents the transmission of the explosion to the explosive atmosphere surrounding the enclosure

3.34 flameproof joint place where the corresponding surfaces of two parts of an enclosure, or the conjunction of enclosures, come together and which prevents the transmission of an internal explosion to the explosive gas atmosphere surrounding the enclosure

[SOURCE: EN 60079-1:2007, 3.3] 3.34.1 gap of flameproof joint distance between the corresponding surfaces of a flameproof joint when the electrical apparatus enclosure has been assembled

Note 1 to entry: For cylindrical surfaces, forming cylindrical joints, the gap is the difference between the diameters of the bore and the cylindrical component. [SOURCE: EN 60079-1:2007, 3.6] 3.34.2 width of flameproof joint

shortest path through a flameproof joint from the inside to the outside of a flameproof enclosure

[SOURCE: EN 60079-1:2007, 3.4] 3.35 flame velocity Sf velocity of a flame front relative to a fixed reference point [SOURCE: EN 15089:2009, 3.14] 3.36 flammable substances

3.36.1 flammable gas or vapour gas or vapour which, when mixed with air in certain proportions, will form an explosive gas atmosphere [SOURCE: EN 60079-10-1:2009, 3.22] 3.36.2 flammable liquid liquid capable of producing a flammable vapour under any foreseeable operating conditions [SOURCE: EN 60079-10-1:2009, 3.21, modified] SIST EN 13237:2013

EN 13237:2012 (E) 14 3.36.3 flammable mist droplets of liquid, dispersed in air so as to form an explosive atmosphere

[SOURCE: EN 60079-10-1:2009, 3.23] 3.37 flammable/combustible substance substance in the form of gas, vapour, liquid, solid, or mixtures of these, able to undergo an exothermic reaction with air when ignited

3.38 flash point lowest liquid temperature at which, under certain standardised conditions, a liquid gives off vapours in a quantity such as to be capable of forming an ignitable vapour/air mixture [SOURCE: EN 60079-10-1:2009, 3.24] 3.39 functional safety part of the overall safety relating to the intended use in terms of the function and integrity of the protective system including any safety related devices that are part of the protective system performance

Note 1 to entry: Functional safety covers all aspects where safety depends on the correct functioning of the protective system and other technology safety-related systems.

Note 2 to entry: This definition deviates from the definition in EN 61508-4 to reflect differences in explosion safety terminology. [SOURCE: EN 15233:2007, 3.2] 3.39.1 functional safety estimation determination of the probability of occurrence of the failures violating the functional safety of the protective system [SOURCE: EN 15233:2007, 3.4] 3.39.2 functional safety evaluation procedure to determine whether the functional safety of the protective system meets the predefined acceptance criteria [SOURCE: EN 15233:2007, 3.5] 3.40 hybrid mixture mixture of flammable substances with air in different physical states 3.41 ignition propagation of a flame away from the ignition source position 3.42 ignition hazard

occurrence of a potential ignition source that is capable of igniting an explosive atmosphere

[SOURCE: EN 15198:2007, 3.2] SIST EN 13237:2013
EN 13237:2012 (E) 15 3.43 ignition risk

probability of occurrence of an ignition source that is capable of igniting an explosive atmosphere

[SOURCE: EN 15198:2007, 3.1] 3.43.1 ignition risk estimation determination of the probability of the occurrence of an ignition source

[SOURCE: EN 15198:2007, 3.5] 3.43.2 ignition risk evaluation procedure to determine whether the intended level of protection (related to the equipment category) has been achieved

[SOURCE: EN 15198:2007, 3.6] 3.44 ignition source

3.44.1 possible ignition source any kind of ignition source Note 1 to entry: See EN 1127-1 for a list of all possible ignition sources. Note 2 to entry: See Figure 2. [SOURCE: EN 13463-1:2009, 3.5] 3.44.2 equipment related ignition source any possible ignition source, which is caused by the equipment under consideration regardless of its ignition capability Note 1 to entry: These are sometimes called "relevant ignition sources"; however this can lead to misunderstanding as to whether the ignition source is relevant in terms of it being present, in terms of its ignition capability or in terms of whether it is present in the equipment or not.

Note 2 to entry: All equipment related ignition sources are considered in the ignition hazard assessment to determine whether they are potential ignition sources. Note 3 to entry: See Figure 2. [SOURCE: EN 13463-1:2009, 3.4] 3.44.3 potential ignition source equipment related ignition source that has the capability to ignite an explosive atmosphere (i.e. to become an effective ignition source) Note 1 to entry: The probability of becoming effective determines the equipment category (they may arise in normal operation, expected malfunction, rare malfunction). Note 2 to entry: See Figure 2. [SOURCE: EN 13463-1:2009, 3.5] SIST EN 13237:2013

EN 13237:2012 (E) 16 3.44.4 effective ignition source potential ignition source which is able to ignite an explosive atmosphere when consideration is taken of when it occurs (i.e. in normal operation, expected malfunction or rare malfunction) whereby the intended category is determined Note 1 to entry: An effective ignition source is a potential ignition source which can ignite the explosive atmosphere if preventive or protective measures are not used. Note 2 to entry: For example the frictional heat which may be produced by a bearing is a possible ignition source. This is an equipment related ignition source if the piece of equipment contains a bearing. If the energy which may be produced by the friction in the bearing is capable of igniting an explosive atmosphere then this is a potential ignition source. Whether this potential ignition source is effective depends on the probability that it will occur in a particular situation (e.g. following loss of lubrication). Note 3 to entry: See Figure 2. [SOURCE: EN 13463-1:2009, 3.6]

Figure 2 — Relationship between ignition source definitions
3.45 auto ignition temperature

Ti lowest temperature (of a hot surface) at which under specified test conditions an ignition of a flammable gas or flammable vapour in mixture with air or air/inert gas occurs

[SOURCE: EN 14522:2005, 3.1] Note 1 to entry: In literature, auto ignition temperature is also referred to as self ignition temperature. In the case of dusts, the respective safety characteristic is referred to as minimum ignition temperature. 3.45.1 minimum ignition temperature of a dust cloud lowest temperature of a hot surface on which the most ignitable mixture of the dust with air is ignited under specified test conditions

SIST EN 13237:2013

EN 13237:2012 (E) 17 3.45.2 minimum ignition temperature of a dust layer lowest temperature of a hot surface at which ignition occurs in a dust layer under specified test conditions

3.46 inert gas non-flammable gas which will not support combustion and does not react to produce a flammable gas [SOURCE: EN 14034-4:2004+A1:2011, 3.4] 3.47 inerting replacement of atmospheric oxygen in a system by a non-reactive, non-flammable gas, to make the atmosphere within the system unable to propagate flame [SOURCE: CEN/TR 15281:2006, 3.1.1] 3.48 KSt dust specific, volume independent characteristic which is calculated using the cubic law equation (dp /dt )max ·V1/3 =const.= KSt [SOURCE: EN 14034-2:2006+A1:2011, 3.8] 3.49 limiting

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