SIST EN 1127-2:2014
(Main)Explosive atmospheres - Explosion prevention and protection - Part 2: Basic concepts and methodology for mining
Explosive atmospheres - Explosion prevention and protection - Part 2: Basic concepts and methodology for mining
EN 1127-2 specifies methods for explosion prevention and protection in mining by outlining the basic concepts and methodology for the design and construction of equipment, protective systems and components. This European Standard applies to Group I equipment, protective systems and components intended for use in underground parts of mines and those parts of their surface installations at risk from firedamp and/or combustible dust. This European Standard specifies methods for the identification and assessment of hazardous situations that may lead to explosions and describes the design and construction measures appropriate for the required safety. This is achieved by - risk assessment; - risk reduction. The safety of equipment, protective systems, and components can be achieved by eliminating hazards and/or limiting the risk, i.e. a) by appropriate design (without using safeguarding); b) by safeguarding; c) by information for use; d) by any other preventive measures. Measures in accordance with a) (prevention) and b) (protection) against explosions are dealt with in Clause 6 of this standard; measures according to c) against explosions are dealt with in Clause 7 of this standard. Measures in accordance with d) are not described in this European Standard. They are dealt with in EN ISO 12100:2010, Clause 6. The preventive and protective measures described in this European Standard will not provide the required level of protection unless the equipment, protective systems and components are operated in line with their intended use and are installed and maintained according to the relevant codes of practice or requirements. This standard is applicable to any equipment, protective systems and components intended to be used in potentially explosive atmospheres. These atmospheres can arise from flammable materials processed, used or released by the equipment, protective systems and components or from materials in the vicinity of the equipment, protective systems and components and/or from the materials of construction of the equipment, protective systems and components. As shot firing can release potentially explosive atmospheres, this standard is also applicable to the equipment used for shot firing, apart from the explosives and detonators. This standard is applicable to equipment, protective systems and components at all stages of use. This standard is not applicable to: - medical devices intended for use in a medical environment; - equipment, protective systems and components where the explosion hazard results exclusively from the presence of explosives or unstable chemical substances; - equipment, protective systems and components where the explosion can result from reaction of substances with oxidising agents other than atmospheric oxygen or by other hazardous reactions or conditions other than atmospheric conditions; - equipment intended for use in domestic and non-commercial environments where explosive atmospheres may only rarely be created and solely as a result of the accidental leakage of fuel gas; - personal protective equipment covered by Directive 89/686/EEC; the design and construction of systems containing desired, controlled combustion processes, unless they can act as ignition sources in potentially explosive atmospheres; - mines where firedamp and/or combustible dust are not naturally present and surface installations such as coal preparation plants, power plants, coke oven plants etc. in which an explosive atmosphere can be present, but which are not part of a coal mine. These are covered by EN 1127-1:2011.
Explosionsfähige Atmosphären - Explosionsschutz - Teil 2: Grundlagen und Methodik in Bergwerken
Diese Europäische Norm legt allgemeine Verfahrensweisen für den Explosionsschutz im Bergbau fest, indem grundlegende Konzepte und Verfahren für die Konstruktion und den Bau von Geräten, Schutzsystemen und Komponenten dargelegt werden.
Diese Europäische Norm gilt für Geräte, Schutzsysteme und Komponenten der Gruppe I zur Verwendung in Untertagebetrieben von Bergwerken sowie deren Übertageanlagen, die durch Grubengas und/oder brennbare Stäube gefährdet werden können.
ANMERKUNG Detaillierte Informationen über spezielle Geräte, Schutzsysteme und Komponenten sind in entsprechenden Einzelnormen zusammengefasst. Für Konstruktion und Bau von Explosionsschutzmaßnahmen müssen die sicherheitsrelevanten Daten der brennbaren Stoffe und explosionsfähigen Atmosphären bekannt sein.
Diese Europäische Norm legt Verfahren zum Erkennen und Beurteilen von gefährlichen Situationen, die zu Explosionen führen können, fest und beschreibt geeignete Planungs- und Fertigungsmaßnahmen, um die erforderliche Sicherheit zu erreichen. Dies wird erreicht durch
Risikobewertung;
Risikoverringerung.
Die Sicherheit von Geräten, Schutzsystemen und Komponenten kann durch das Beseitigen von Gefährdungen und/oder die Begrenzung des Risikos erreicht werden durch
a) geeignete konstruktive Auslegung (ohne Anwendung von technischen Schutzmaßnahmen);
b) technische Schutzmaßnahmen;
c) Benutzerinformation;
d) sonstige Vorsichtsmaßnahmen.
Explosionsschutzmaßnahmen nach a) (Vorbeugung) und b) (Schutz) werden in Abschnitt 6 dieser Norm behandelt, Maßnahmen nach c) in Abschnitt 7. Maßnahmen nach d) sind in dieser Norm nicht beschrieben; letztere werden in EN ISO 12100:2010, Abschnitt 6, behandelt.
Die in dieser Europäischen Norm beschriebenen Schutzmaßnahmen führen nur dann zu der erforderlichen Sicherheit, wenn die Geräte, Schutzsysteme und Komponenten bestimmungsgemäß betrieben und entsprechend den für sie geltenden Regeln oder Vorschriften installiert und gewartet werden.
Diese Norm gilt für alle Geräte, Schutzsysteme und Komponenten, die bestimmungsgemäß in explosionsgefährdeten Bereichen eingesetzt werden. Solche Bereiche können vorliegen, wenn brennbare Stoffe verarbeitet, verwendet oder von den Geräten, Schutzsystemen und Komponenten freigesetzt werden. Sie können auch auftreten in der Umgebung von Geräten, Schutzsystemen und Komponenten sowie durch die Konstruktionsmaterialien der Geräte, Schutzsysteme und Komponenten.
Da durch Sprengarbeiten möglicherweise explosionsfähige Atmosphären freigesetzt werden können, gilt diese Norm auch für Geräte zur Sprengarbeit, nicht aber für Sprengstoffe und Zünder.
Diese Norm gilt für Geräte, Schutzsysteme und Komponenten in allen Anwendungsstadien.
Diese Norm ist nicht anwendbar auf:
medizinische Geräte zur bestimmungsgemäßen Verwendung in medizinischen Bereichen;
Geräte, Schutzsysteme und Komponenten, bei denen die Explosionsgefahr ausschließlich durch die Anwesenheit von Sprengstoffen oder chemisch instabilen Stoffen hervorgerufen wird;
Geräte, Schutzsysteme und Komponenten, bei denen die Explosion durch Reaktion von Stoffen mit anderen Oxidationsmitteln als Luftsauerstoff oder durch andere gefährliche Reaktionen oder andere als atmosphärische Bedingungen erfolgen kann;
Geräte, die zur Verwendung in häuslicher und nichtkommerzieller Umgebung vorgesehen sind, in der eine explosionsfähige Atmosphäre nur selten und lediglich infolge eines unbeabsichtigten Brennstoffaustritts gebildet werden kann;
persönliche Schutzausrüstungen im Sinne der Richtlinie 89/686/EWG; Planung und Ausführung von Systemen, die beabsichtigte, gesteuerte Verbrennungsvorgänge umfassen, falls sie nicht als Zündquellen in explosionsgefährdeten Bereichen wirken können;
Atmosphères explosives - Prévention de l'explosion et protection contre l'explosion - Partie 2: Notions fondamentales et méthodologie dans l'exploitation des mines
La présente Norme Européenne définit des méthodes pour la prévention de l’explosion et la protection contre les effets de l’explosion dans l’industrie minière, en précisant les notions fondamentales et la méthodologie relatives à la conception et à la construction des appareils, systèmes de protection et composants.
La présente Norme Européenne s’applique aux appareils, systèmes de protection et composants du groupe I destinés aux travaux souterrains des mines et aux parties de leurs installations de surface susceptibles d’être mis en danger par le grisou et/ou des poussières inflammables.
NOTE Des informations détaillées sur les appareils, les systèmes de protection et les composants spécifiques sont données dans des normes séparées appropriées. La conception et l’élaboration des mesures de protection contre l’explosion nécessitent la détermination des données relatives à la sécurité des substances inflammables et des atmosphères explosives.
La présente Norme Européenne spécifie des méthodes d’identification et d’appréciation des situations dangereuses pouvant conduire à l’explosion ainsi que les mesures de conception et de construction appropriées pour assurer la sécurité requise. Celle-ci est obtenue par :
l’appréciation du risque ;
la réduction du risque.
La sécurité des appareils, systèmes de protection et composants peut être obtenue par l’élimination des phénomènes dangereux et/ou la limitation du risque, c’est-à-dire :
a) par une conception appropriée (sans utiliser de dispositifs de protection) ;
b) à l’aide de dispositifs de protection ;
c) au moyen d’informations pour l’utilisation ;
d) par toute autre mesure de prévention.
Les mesures contre les explosions correspondant à l’alinéa a) (prévention) et à l’alinéa b) (protection) sont traitées dans l’Article 6 de la présente norme. Les mesures contre l’explosion correspondant à l’alinéa c) sont traitées dans l’Article 7 de la présente Norme. Les mesures correspondant à l’alinéa d) ne sont pas décrites dans la présente Norme Européenne. Elles sont traitées dans l’Article 6 de l’EN ISO 12100:2010.
Les mesures de prévention et de protection décrites dans la présente Norme Européenne ne procurent le niveau requis de sécurité que si les appareils, systèmes de protection et composants sont employés conformément à leur utilisation prévue et sont installés et entretenus conformément aux codes de bonnes pratiques ou exigences approprié(e)s.
La présente Norme est applicable à tout type d’appareil, système de protection et composant destiné à être utilisé dans des atmosphères explosibles. Ces atmosphères peuvent être générées par les substances inflammables traitées et manipulées dans les appareils, systèmes de protection et composants ou évacuées par ceux-ci, par les substances se trouvant à proximité des appareils, systèmes de protection et composants et/ou par les matériaux constitutifs des appareils, systèmes de protection et composants.
Dans la mesure où l’abattage à l’explosif peut créer une atmosphère explosible, la présente Norme s’applique aussi aux appareils utilisés pour l’abattage à l’explosif, à l’exception des explosifs et détonateurs.
Cette Norme est applicable aux appareils, systèmes de protection et composants à tous les stades de leur utilisation.
Cette Norme ne s’applique pas :
aux dispositifs médicaux destinés à être utilisés dans un environnement médical ;
aux appareils, systèmes de protection et composants lorsque le phénomène dangereux d’explosion est exclusivement dû à la présence de matières explosives ou de substances chimiques instables ;
Eksplozivne atmosfere - Protieksplozijska zaščita - 2. del: Osnovni pojmi in metodologija za rudarstvo
EN 1127-2 določa metode za preprečevanje in zaščito pred eksplozijami v rudarstvu z opisom osnovnih konceptov in metodologij za načrtovanje in konstrukcijo opreme, zaščitnih sistemov in komponent. Ta evropski standard velja za opremo skupine I, zaščitne sisteme in sestavne dele za uporabo v podzemnih delih rudnikov in tiste dele površinskih naprav, ki jih ogroža jamski eksplozivni plin ali vnetljiv prah. Ta evropski standard določa metode za ugotavljanje in ocenjevanje nevarnih situacij, ki lahko povzročijo eksplozije, in opisuje strukturne in konstrukcijske ukrepe, primerne za zahtevano varnost. To je doseženo z - oceno tveganja; - zmanjšanjem tveganja. Varnost opreme, zaščitnih sistemov in komponent je mogoče doseči z odpravo nevarnosti in/ali omejevanjem tveganja, tj. a) z ustreznim načrtovanjem (brez uporabe zaščite); b) z zaščito; c) z informacijami za uporabo; d) s poljubnimi drugimi preventivnimi ukrepi. Ukrepi v skladu z a) (preprečevanje) in b) (zaščita) proti eksploziji so obravnavani v točki 6 tega standarda; ukrepi v skladu s c) proti eksploziji so obravnavani v točki 7 tega standarda. Ukrepi v skladu z d) niso opisani v tem evropskem standardu. Obravnavani so v točki 6 standarda EN ISO 12100:2010. Preventivni in zaščitni ukrepi, opisani v tem evropskem standardu, ne zagotavljajo zahtevane ravni zaščite, razen če se z opremo, zaščitnimi sistemi in komponentami ravna v skladu z njihovim namenom uporabe in so nameščeni in vzdrževani v skladu z ustreznimi kodeksi ravnanja ali zahtev. Ta standard velja za vso opremo, zaščitne sisteme in komponente, ki so namenjeni za uporabo v potencialno eksplozivnih atmosferah. Te atmosfere lahko nastanejo iz vnetljivih materialov, ki jih obdeluje, uporablja ali sprošča oprema, zaščitni sistemi in sestavni del ali materiali v bližini opreme, zaščitnih sistemov in sestavnih delov in/ali iz konstrukcijskih materialov opreme, zaščitnih sistemov in komponent. Ker lahko streljanje povzroči nastanek potencialno eksplozivnih atmosfer, se ta standard uporablja tudi za opremo, ki se uporablja za streljanje, razen eksplozivov in detonatorjev. Ta standard se uporablja za opremo, zaščitne sisteme in sestavne dele v vseh fazah uporabe. Ta standard se ne uporablja za: - medicinske pripomočke, namenjene uporabi v medicinskem okolju; - opremo, zaščitne sisteme in komponente, kjer je nevarnost eksplozije izključno posledica navzočnosti eksplozivov ali nestabilnih kemikalij; - opremo, zaščitne sisteme in komponente, kjer je eksplozija lahko posledica reakcije snovi z oksidacijsko snovjo, razen atmosferskega kisika ali drugih nevarnih reakcij ali pogojev, razen atmosferskih pogojev; - opremo, namenjeno za uporabo v domačem in nekomercialnem okolju, kjer eksplozivna atmosfera nastane zelo redko, in sicer izključno zaradi naključnega uhajanja kurilnega plina; - osebno zaščitno opremo, zajeto z Direktivo 89/686/EGS; - projektiranje in gradnjo sistemov, ki vsebujejo želene, nadzorovane procese zgorevanja, razen če lahko delujejo kot viri vžiga v potencialno eksplozivnih atmosferah; - rudnike, kjer jamski eksplozivni plin in/ali vnetljiv prah nista naravno prisotna in površinske naprave, kot so obrati za pripravo premoga, elektrarne, peči na koks itd., v katerih je lahko prisotna eksplozivna atmosfera, vendar niso del premogovnika. Te so zajete v standardu v EN 1127-1:2011.
General Information
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Explosionsfähige Atmosphären - Explosionsschutz - Teil 2: Grundlagen und Methodik in BergwerkenAtmosphères explosives - Prévention de l'explosion et protection contre l'explosion - Partie 2: Notions fondamentales et méthodologie dans l'exploitation des minesExplosive atmospheres - Explosion prevention and protection - Part 2: Basic concepts and methodology for mining73.020Rudarstvo in kamnolomsko izkopavanjeMining and quarrying13.230Varstvo pred eksplozijoExplosion protectionICS:Ta slovenski standard je istoveten z:EN 1127-2:2014SIST EN 1127-2:2014en01-september-2014SIST EN 1127-2:2014SLOVENSKI
STANDARDSIST EN 1127-2:2002+A1:20081DGRPHãþD
SIST EN 1127-2:2014
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 1127-2
June 2014 ICS 13.230; 73.100.01 Supersedes EN 1127-2:2002+A1:2008English Version
Explosive atmospheres - Explosion prevention and protection - Part 2: Basic concepts and methodology for mining
Atmosphères explosives - Prévention de l'explosion et protection contre l'explosion - Partie 2: Notions fondamentales et méthodologie dans l'exploitation des mines
Explosionsfähige Atmosphären - Explosionsschutz - Teil 2: Grundlagen und Methodik in Bergwerken This European Standard was approved by CEN on 7 May 2014.
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 © 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1127-2:2014 ESIST EN 1127-2:2014
EN 1127-2:2014 (E) 2
Contents Page Foreword .4 Introduction .5 1 Scope .8 2 Normative references .9 3 Terms and definitions . 10 4 Risk assessment . 11 4.1 General . 11 4.2 Identification of explosion hazards. 11 4.3 Identification of ignition hazards . 11 4.4 Estimation of the possible effects of an explosion . 11 5 Possible ignition sources . 12 5.1 Hot surfaces . 12 5.2 Flames and hot gases (including hot particles) . 12 5.3 Mechanically generated sparks . 12 5.4 Electrical equipment . 12 5.5 Stray electric currents . 12 5.6 Static electricity . 13 5.7 Lightning . 13 5.8 Radio frequency (RF) electromagnetic waves from 104 Hz to 3 × 1011 Hz (high frequency) . 13 5.9 Electromagnetic waves from 3 × 1011 Hz to 3 × 1015 Hz . 13 5.10 Ionizing radiation . 13 5.11 Ultrasonics . 13 5.12 Adiabatic compression and shock waves . 13 5.13 Exothermic reactions, including self-ignition of dusts . 13 6 Risk reduction . 14 6.1 Fundamental principles . 14 6.2 Avoidance or reduction of explosive atmosphere . 14 6.2.1 Process parameters . 14 6.2.2 Design and construction of equipment, protective systems and components containing flammable substances . 16 6.3 Classification of hazardous atmospheric conditions . 16 6.3.1 General . 16 6.3.2 Hazardous atmospheric conditions . 17 6.4 Requirements for the design and construction of equipment, protective systems and components by avoidance of effective ignition sources. 17 6.4.1 General . 17 6.4.2 Hot surfaces . 18 6.4.3 Flames and hot gases . 19 6.4.4 Mechanically generated sparks . 19 6.4.5 Electrical equipment . 20 6.4.6 Stray electric currents . 20 6.4.7 Static electricity . 20 6.4.8 Lightning . 20 6.4.9 Radio frequency (RF) electromagnetic waves from 104 Hz to 3 × 1011 Hz . 20 6.4.10 Electromagnetic waves from 3 × 1011 Hz to 3 × 1015 Hz . 21 6.4.11 Ionizing radiation . 22 SIST EN 1127-2:2014
EN 1127-2:2014 (E) 3 6.4.12 Ultrasonics . 22 6.4.13 Adiabatic compression and shock waves . 22 6.4.14 Exothermic reactions, including self-ignition of dusts . 22 6.5 Requirements for design and construction of equipment, protective systems and components to reduce the explosion effects . 23 6.5.1 General . 23 6.5.2 Special equipment for underground mining. 23 6.6 Provisions for emergency measures . 24 6.7 Principles for measuring and control systems for explosion prevention and protection . 24 7 Information for use . 24 7.1 General . 24 7.2 Information for commissioning, maintenance and repair to prevent explosion . 25 7.3 Qualifications and training . 26 Annex A (informative)
Relation between categories and hazardous atmospheric conditions . 27 Annex B (normative)
Tools for use in potentially explosive atmospheres . 28 Annex C (informative)
Significant technical changes between this document and the previous edition of this European Standard . 29 Annex ZA (informative)
Relationship between this European Standard and the Essential Requirements of EU Directive 94/9/EC . 30 Annex ZB (informative)
Relationship between this European Standard and the Essential Requirements of EU Directive 2006/42/EC . 31 Bibliography . 32
SIST EN 1127-2:2014
EN 1127-2:2014 (E) 4
Foreword This document (EN 1127-2:2014) 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 December 2014 and conflicting national standards shall be withdrawn at the latest by December 2014. 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 1127-2:2002+A1:2008. 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 Directives. For relationship with EU Directives, see informative Annexes ZA and ZB, which are an integral part of this document. EN 1127, Explosive atmospheres — Explosion prevention and protection is composed of the following parts: — Part 1: Basic concepts and methodology — Part 2: Basic concepts and methodology for mining (the present document) Annex C provides details of significant changes between this document and the previous edition. 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. SIST EN 1127-2:2014
EN 1127-2:2014 (E) 5 Introduction General CEN and CENELEC are producing a series of standards to assist designers, manufacturers and other interested bodies to interpret the essential safety requirements in order to achieve conformity with European legislation. Within this series of standards, CEN has undertaken to draw up a standard to give guidance in the field of explosion prevention and protection, as hazards from explosions are to be considered in accordance with EN ISO 12100. In accordance with EN ISO 12100, it is a type A standard. Special considerations for mining Explosions can result from: — materials processed or used by the equipment and components, e.g. minerals obtained as part of the winning process; — materials released by the equipment and components; — materials in the vicinity of the equipment, protective systems and components; — materials of which the equipment, protective systems and components are constructed. As the explosion protection of equipment, protective systems and components depends on: — the design and construction of the equipment, protective systems and components; — the intended use; — the foreseeable misuse; — the ambient conditions; — the materials extracted and handled. This standard also includes safety aspects related to these factors, i.e. it is imperative that the manufacturer consider how and for what the equipment, protective systems and components will be used and take this into account during their design and construction. Only in this way can hazards inherent in equipment, protective systems and components be reduced. NOTE 1 This standard can also serve as a guide for users of equipment, protective systems and components when assessing the risk of explosion in the workplace and selecting the appropriate equipment, protective systems and components. Mines can be either gassy or non-gassy depending upon the mineral/material being extracted and whether or not firedamp can occur in the workings. It is usual practice to consider all coal mines as gassy mines. Non-coal mines can, however, also be susceptible to the occurrence of firedamp, e.g. if minerals/materials are being extracted in the vicinity of oil-bearing strata or unworked coal seams which are disturbed by the extraction process or mines susceptible to outbursts of flammable gas. In mines where flammable minerals/materials are extracted, there can also be a risk of explosions because small particles of the extracted product can be blown into the air to form dust/air mixtures able to support rapid combustion. Combustible dust can either be an explosion risk on its own (when in the form of an explosive dust/air mixture), or it can settle in layers which may be blown from the floor and sides of the roadways by a SIST EN 1127-2:2014
EN 1127-2:2014 (E) 6
firedamp explosion. In the latter case, the explosive violence can increase many times as more and more fuel in the form of combustible dust is raised by a blast wave and added to the flame as it travels along the roadways. The risk of an explosive atmosphere occurring and its consequences will therefore vary from mine to mine, depending on the type of mine, its layout, the mineral being extracted and the likelihood of firedamp and/or combustible dust occurring. In coal mining, firedamp and coal dust naturally associated with the coal is released by the activity of the miners. Therefore, the potential explosion risk is greater as a result of explosive air/gas or air/dust mixtures forming that cannot be totally excluded by the preventive measures taken. Firedamp/air mixtures are usually diluted by the ventilation and evacuated to the surface via the mine workings so that the gas content in normal operation is kept far below the lower explosion limit. However, as a result of system malfunction (e.g. fan failure), sudden release of large gas quantities (gas outbursts) or intensified gas release caused by decreasing air pressure or by increased coal production, the permissible gas concentration thresholds may be exceeded. The explosive atmosphere caused in this way, even though limited in space and/or time, may cause a hazard not just at its point of origin but also in the escape roads, waste air paths and other connected mine structures in the mine layout. Coal dust/air mixtures are usually neutralized at the dust source by water sprays, dust removal systems on heading machines and/or treating with inert dust in order to reduce the explosive potential. However, an explosion hazard can exist if explosive dust can become airborne, e.g. at transfer points, in bunkers and other conveying systems. In contrast to surface industries, in gassy mines electrical and non-electrical equipment and mining personnel are in permanent contact with gas and/or dust/air mixtures which, under unfavourable conditions, may constitute explosive atmospheres. Accordingly, particularly stringent safety requirements are in force for explosion protection and escape possibilities in the event of a hazard. Due to the possibly devastating effects of underground gas/dust explosions, underground mining is permitted only well outside the explosion range. In gassy mines, the decision as to whether or not mine workers can operate in a particular workplace depends upon the atmospheric conditions prevailing at the time. Traditionally, a factor of safety is also introduced so that it is common practice throughout the European member states for equipment to be de-energized or made safe and for miners to be withdrawn from their workplace if the atmospheric conditions attain a specific percentage of the lower explosion limit (LEL) of methane (firedamp) in air as defined by the relevant national legislation of the member states. NOTE 2 The current limit values for disconnecting equipment and withdrawing personnel are different in each member state. Two different ranges of explosive atmospheres originating from the intended installation and use of the equipment are taken into account when dealing with requirements for Equipment Groups M 2 and M 1: — potentially explosive atmosphere — range between 0 % and below LEL or above UEL up to 100 % of firedamp in air; — explosive atmosphere — range between LEL and UEL of firedamp in air. In mine workings with explosive atmospheres, only M 1 equipment is acceptable as it has a very high level of protection. M 1 equipment, e.g. telephones or gas measuring equipment may continue to be operated in explosive atmospheres, because they are safe even in the event of rare equipment faults. This is ensured by the existence of two independent protective measures or double fail-safe systems. In mine workings with potentially explosive atmospheres, both M 1 and M 2 equipment may be used. M 2 equipment may be used as it has a high level of protection and is suitable for the severe conditions in mining. In an explosive atmospheres, M 2 equipment needs to be capable of being disconnected or made safe. SIST EN 1127-2:2014
EN 1127-2:2014 (E) 7 NOTE 3 Under special conditions, it might be necessary to operate M 2 equipment in an explosive atmosphere for a short time, e.g. when personnel are escaping from mine workings with high firedamp readings with their M 2 caplights switched on, when personnel are being recovered by the mine rescue service or the firedamp extraction system has been started up. M 1 and M 2 equipment can only be operated with the characteristics specified by the manufacturer as only then do they ensure the relevant level of protection. The manufacturer specifies the operating characteristics for the equipment. In practice, national regulations require that gas measurements be taken at certain points and at specific intervals and suitable measures are taken to de-energize the equipment either manually or automatically if the firedamp concentration reaches a certain value. A subdivision into hazards caused by an explosive gas atmosphere and those caused by an explosive dust atmosphere is, in contrast to EN 1127-1:2011, not advisable in underground mining as the hazard to the mine workings can be caused simultaneously by firedamp and by clouds of combustible dust. Therefore, the explosion protection measures will always cover both, i.e. the hazard caused by firedamp and the one caused by combustible dust. The definition of potentially explosive atmospheres in coal mines susceptible to firedamp based on Directive 94/9/EC extends the definition of potentially explosive atmosphere to include combustible dust as well as firedamp. Extensive research has shown that the minimum ignition energy (MIE) of coal dust/air mixtures is several hundred times that of firedamp/air mixtures and that the maximum experimental safe gap (MESG) of coal dust particles is more than double that for firedamp. It is therefore reasonable to assume that the equipment, protective systems and components which are designed and constructed for use in firedamp/air mixtures are also suitable for use in coal dust/air mixtures. The comparison of methane and coal dust experimental data relates only to atmospheres (mixtures of gas and/or dust with air), not to dust layers. Additional precautions are required when considering coal dust deposits as, in this case, the maximum surface temperature of the equipment (limited to 150 °C for Group I equipment) on which the deposits can form can be limited to values below the minimum ignition temperature. It is vital to bear in mind that in both coal mines and non-coal mines there can be areas where firedamp does not occur but where there is a risk of explosion because of combustible dust. SIST EN 1127-2:2014
EN 1127-2:2014 (E) 8
1 Scope This European Standard specifies methods for explosion prevention and protection in mining by outlining the basic concepts and methodology for the design and construction of equipment, protective systems and components. This European Standard applies to Group I equipment, protective systems and components intended for use in underground parts of mines and those parts of their surface installations at risk from firedamp and/or combustible dust. NOTE Detailed information on specific equipment, protective systems and components is contained in the relevant individual standards. Safety-relevant data regarding flammable materials and explosive atmospheres are required for the design and construction of the explosion protection measures. This European Standard specifies methods for the identification and assessment of hazardous situations that may lead to explosions and describes the design and construction measures appropriate for the required safety. This is achieved by — risk assessment; — risk reduction. The safety of equipment, protective systems, and components can be achieved by eliminating hazards and/or limiting the risk, i.e. a) by appropriate design (without using safeguarding); b) by safeguarding; c) by information for use; d) by any other preventive measures. Measures in accordance with a) (prevention) and b) (protection) against explosions are dealt with in Clause 6 of this standard; measures according to c) against explosions are dealt with in Clause 7 of this standard. Measures in accordance with d) are not described in this European Standard. They are dealt with in EN ISO 12100:2010, Clause 6. The preventive and protective measures described in this European Standard will not provide the required level of protection unless the equipment, protective systems and components are operated in line with their intended use and are installed and maintained according to the relevant codes of practice or requirements. This standard is applicable to any equipment, protective systems and components intended to be used in potentially explosive atmospheres. These atmospheres can arise from flammable materials processed, used or released by the equipment, protective systems and components or from materials in the vicinity of the equipment, protective systems and components and/or from the materials of construction of the equipment, protective systems and components. As shot firing can release potentially explosive atmospheres, this standard is also applicable to the equipment used for shot firing, apart from the explosives and detonators. This standard is applicable to equipment, protective systems and components at all stages of use. This standard is not applicable to: — medical devices intended for use in a medical environment; SIST EN 1127-2:2014
EN 1127-2:2014 (E) 9 — equipment, protective systems and components where the explosion hazard results exclusively from the presence of explosives or unstable chemical substances; — equipment, protective systems and components where the explosion can result from reaction of substances with oxidising agents other than atmospheric oxygen or by other hazardous reactions or conditions other than atmospheric conditions; — equipment intended for use in domestic and non-commercial environments where explosive atmospheres may only rarely be created and solely as a result of the accidental leakage of fuel gas; — personal protective equipment covered by Directive 89/686/EEC; the design and construction of systems containing desired, controlled combustion processes, unless they can act as ignition sources in potentially explosive atmospheres; — mines where firedamp and/or combustible dust are not naturally present and surface installations such as coal preparation plants, power plants, coke oven plants etc. in which an explosive atmosphere can be present, but which are not part of a coal mine. These are covered by EN 1127-1:2011. 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. EN 1127-1:2011, Explosive atmospheres — Explosion prevention and protection — Part 1: Basic concepts and methodology EN 1710, Equipment and components intended for use in potentially explosive atmospheres in underground mines EN 13237, Potentially explosive atmospheres — Terms and definitions for equipment and protective systems intended for use in potentially explosive atmospheres EN 13463-1:2009, Non-electrical equipment for use in potentially explosive atmospheres — Part 1: Basic method and requirements EN 13463-6, Non-electrical equipment for use in potentially explosive atmospheres — Part 6: Protection by control of ignition source 'b' EN 13478, Safety of machinery — Fire prevention and protection EN 14373, Explosion suppression systems EN 14460, Explosion resistant equipment EN 14797, Explosion venting devices EN 15089, Explosion isolation systems EN 60079-0, Explosive atmospheres — Part 0: Equipment — General requirements EN 60079-2, Explosive atmospheres — Part 2: Equipment protection by pressurized enclosure “p” EN ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk reduction (ISO 12100:2010) SIST EN 1127-2:2014
EN 1127-2:2014 (E) 10
EN ISO 13849-1, Safety of machinery — Safety-related parts of control systems — Part 1: General principles for design (ISO 13849-1) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 13237:2012 and the following apply. 3.1 firedamp any potentially explosive mixture of gases or any flammable gas naturally occurring in a mine Note 1 to entry: As firedamp consists mainly of methane, the terms firedamp and methane are used frequently in mining practice as synonyms. 3.2 protection against firedamp explosions explosion prevention and protection in underground parts of mines and those parts of surface installations of such mine
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