1、BSI Standards PublicationPD CEN/TR 16793:2016 Guide for the selection, application and use of flame arrestersPD CEN/TR 16793:2016 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of CEN/TR 16793:2016. The UK participation in its preparation was entrusted to Techn
2、ical Committee EPL/278, Potentially explosive atmospheres - Explosion prevention and protection. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are respo
3、nsible for its correct application. The British Standards Institution 2016. Published by BSI Standards Limited 2016 ISBN 978 0 580 85209 1 ICS 03.220.01; 35.240.60 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authorit
4、y of the Standards Policy and Strategy Committee on 31 January 2016. Amendments/corrigenda issued since publication Date Text affected TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 16793 January 2016 ICS 23.060.40; 13.220.99 English Version Guide for the selection, application and us
5、e of flame arresters Guide pour la slection, lapplication et lutilisation des arrte-flammes R i c h t l i n i e f r d i e A u s w a h l, die Anwendung und den Einsatz von Flammendurchschlagssicherungen This Technical Report was approved by CEN on 22 December 2014. It has been drawn up by the Technic
6、al Committee CEN/TC 305. 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, Ne
7、therlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All
8、rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TR 16793:2016 EPD CEN/TR 16793:2016 8.2 Safety information . 30 8.3 Checking and installing . 30 8.4 Inspection and maintenance intervals . 31 8.5 Liquid seal flame arrester . . 31 9 Commiss
9、ioning checklist . . 32 Bibliography 33 CEN/TR 16793:2016 (E)PD CEN/TR 16793:2016 European foreword This document (CEN/TR 16793:2016) has been prepared by Technical Committee CEN/TC 305 “Potentially explosive atmospheres - Explosion prevention and protection”, the secretariat of which is held by DIN
10、. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. 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 fo
11、r identifying any or all such patent rights. CEN/TR 16793:2016 (E)PD CEN/TR 16793:2016 Introduction The document provided is general in nature and for specific applications further expert advice should be sought. In addition to the content of operating manuals from manufacturers, the local accident
12、prevention regulations, environmental protection and general safety provisions for the devices area of use, as well as relevant laws and national directives, this paper will support the user for a proper use of flame arresters. In Europe, the “Directive 2014/34/EU on equipment and protective systems
13、 intended for use in potentially explosive atmospheres” (ATEX Atmosphres Explosibles) is mandatory for the production and test intended for use of products in potentially explosive atmospheres. Flame arresters are defined as a Protective System. Flame arresters should be tested according to EN ISO 1
14、6852, Flame arresters Performance requirements, test methods and limits for use, to fulfill the health and safety requirements of this directive. Flame arresters are subjected to an EC type examination and are designed for use in areas at risk from explosion. The Directive 1999/92/EC of the European
15、 Parliament and of the Council of 16 December 1999 on minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres - gives the minimum requirements for the improvement of health protection and safety of employers who could be endangere
16、d by explosive atmospheres. The main issues are assessment of explosion risk, zone classification and the explosion protection documents (including requirements for personnel to do engineering, equipment selection, installation, maintenance, repair, etc.). National regulations and/or codes relating
17、to specific industries or applications may exist which have to followed. Flame arresters are required to protect against many types of explosion events within equipment. The safety obtained depends heavily upon correct choice, installation and maintenance of the flame arrester. This cannot be achiev
18、ed without responsible, informed management. CEN/TR 16793:2016 (E)PD CEN/TR 16793:2016 1 Scope This Technical Report is aimed primarily at persons who are responsible for the safe design and operation of installations and equipment using flammable liquids, vapours or gases. This document applies to
19、both industrial and mining applications This document describes possible risks and gives proposals for the protection against these risks by the use of flame arresters. This document gives some guidance to choice of flame arresters according to EN ISO 16852 for different common scenarios and it give
20、s best practice for the installation and maintenance of these flame arresters. 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
21、 references, the latest edition of the referenced document (including any amendments) applies. EN 60079-20-1, Explosive atmospheres Part 20-1: Material characteristics for gas and vapour classification Test methods and data (IEC 60079-20-1) EN ISO 16852:2010, Flame arresters Performance requirements
22、, test methods and limits for use (ISO 16852:2008, including Cor 1:2008 and Cor 2:2009) EN ISO 28300:2008, Petroleum, petrochemical and natural gas industries Venting of atmospheric and low-pressure storage tanks (ISO 28300:2008) 3 Terms, definitions and abbreviated terms 3.1 Terms and definitions F
23、or the purposes of this document, the following terms and definitions apply. 3.1.1 atmospheric condition pressure ranging from 80 kPa to 110 kPa (0,8 bar to 1,1 bar); temperatures ranging from -20 C to +60 C 3.1.2 end-of-line flame arrester flame arrester that is fitted with one pipe connection only
24、 3.1.3 explosion abrupt oxidation or decomposition reaction producing an increase in temperature, pressure, or in both simultaneously 3.1.4 explosion group Ex.G ranking of flammable gas-air mixtures with respect to the MESG Note 1 to entry: See EN ISO 16852:2010, 3.12.2. CEN/TR 16793:2016 (E)PD CEN/
25、TR 16793:2016 3.1.5 explosion-pressure-resistant property of vessels and equipment designed to withstand the expected explosion pressure without becoming permanently deformed 3.1.6 explosion-pressure-shock resistant property of vessels and equipment designed to withstand the expected explosion press
26、ure without rupturing, but allowing permanent deformation 3.1.7 deflagration explosion propagating at subsonic velocity SOURCE: EN ISO 16852:2010, 3.8 3.1.8 detonation explosion propagating at supersonic velocity and characterized by a shock wave SOURCE: EN ISO 16852:2010, 3.9 3.1.9 stable detonatio
27、n detonation progressing through a confined system without significant variation of velocity and pressure characteristics Note 1 to entry: For the atmospheric conditions, test mixtures and test procedures of this International Standard, typical velocities range between 1 600 m/s and 2 200 m/s. SOURC
28、E: EN ISO 16852:2010, 3.10 3.1.10 unstable detonation detonation during the transition of a combustion process from a deflagration into a stable detonation Note 1 to entry: The transition occurs in a limited spatial zone, where the velocity of the combustion wave is not constant and where the explos
29、ion pressure is significantly higher than in a stable detonation. The position of this transition zone depends, amongst other factors, on pipe diameter, pipe configuration, test gas and explosion group. SOURCE: EN ISO 16852:2010, 3.11 3.1.11 flame arrester device fitted to the opening of an enclosur
30、e, or to the connecting pipe work of a system of enclosures, and whose intended function is to allow flow but prevent the transmission of flame SOURCE: EN ISO 16852:2010, 3.1 3.1.12 flame arrester element part of a flame arrester whose principal function is to prevent flame transmission SOURCE: EN I
31、SO 16852:2010, 3.3 CEN/TR 16793:2016 (E)PD CEN/TR 16793:2016 3.1.13 in-line flame arrester flame arrester that is fitted with two pipe connections, one on each side of the flame arrester SOURCE: EN ISO 16852:2010, 3.22 3.1.14 mixture used to represent any mixtures of gas and/or product vapour/air 3.
32、1.15 product equipment, protective systems, safety devices, components and their combinations 3.1.16 protected side side of the plant component to be protected 3.1.17 protective system autonomous devices to stop an explosion immediately and/or limit the effects of explosion flames and pressures 3.1.
33、18 stabilized burning steady burning of a flame stabilized at, or close to, the flame arrester element short time (max. 30 minutes) or endurance burning (for unlimited time) 3.1.19 unprotected side ignition source side 3.1.20 restriction reduction of the diameter of the pipe on the protected side of
34、 a flame arrester Note 1 to entry: For example, a restriction can be a not fully opened valve. 3.2 Abbreviated terms DN nominal size of the connection of a device or pipe fitting LEL lower explosion limit of the explosion range L r pipe length between flame arrester and restriction L u pipe length o
35、n the unprotected side, maximum allowable run-up length for installation p 0 maximum operational pressure T 0 maximum operational temperature MESG maximum experimental safe gap safe gap measured in accordance with EN 60079-20-1 p/v valve pressure and vacuum relief vent valve UEL upper explosion limi
36、t of the explosion range NPSH net positive suction head CEN/TR 16793:2016 (E)PD CEN/TR 16793:2016 Z 0min minimum operational water seal immersion depth when the mixture flow displaces the water from the immersion tubes, where Z 0min Z Rmin Z 0 operational immersion depth, corresponding to Z 0min plu
37、s the manufacturers recommended safety margin Z Rmin minimum water seal immersion depth at rest above the outlet openings of the immersion tubes Z R immersion depth at rest, corresponding to Z Rmin plus the manufacturers recommended safety margin max V safe volume flow rate s V safe volume flow rate
38、 including a safety margin 4 Explosion risks The following content is a summary of the non-binding guide to good practice for implementing the European Parliament and Council Directive 1999/92/EC 1. Three components are necessary at the same time for an explosion to occur. These are visualized in th
39、e so-called explosion triangle (see Figure 1). 1) Air (oxidizer) 2) Fuel (flammable gas) 3) Ignition Source (e.g. spark, hot surface, etc.) Figure 1 Explosion triangle Fuel mixed with air in a suitable ratio (above LEL and below UEL) is called explosive atmosphere. Assessment of explosion risks is f
40、ocused on: the likelihood that an explosive atmosphere will occur, and subsequently on the likelihood that sources of ignition will be present and become effective. Suitable methods for assessing the explosion risks associated with work processes or plant are those which lend themselves to a systema
41、tic approach to checking plant and process safety. An analysis is made of the existing sources of hazardous explosive atmospheres and the effective sources of ignition which could occur at the same time. Explosion risks can in practice be assessed by means of seven questions: CEN/TR 16793:2016 (E)PD
42、 CEN/TR 16793:2016 1) Are flammable substances present? 2) Can sufficient dispersal in air give rise to an explosive atmosphere? 3) Where can explosive atmospheres occur? 4) Is the formation of a hazardous explosive atmosphere possible? 5) Is the formation of hazardous explosive atmospheres reliably
43、 prevented? 6) To what zones can the places with hazardous explosive atmospheres be assigned? 7) Is the ignition of hazardous explosive atmospheres reliably prevented? Depending on the answers of these questions, it could be necessary to apply adequate explosion protection measures. “Explosion prote
44、ction measures“ mean all measures that prevent the formation of hazardous explosive atmospheres, avoid the ignition of hazardous explosive atmospheres or mitigate the effects of explosions. One of the possible measures is to use flame arresters. An idealized representation of the flame acceleration
45、process is presented in Figure 2. Key X pipe L/D 3 deflagration IIB - IIC Y1 flame speed in m s -14 deflagration IIA IIB3 Y2 pressure in bar 5 deflagration to detonation transition 1 flame speed 6 stable detonation 2 pressure Figure 2 Development of an explosion in a pipeline CEN/TR 16793:2016 (E)PD
46、 CEN/TR 16793:2016 5 Technical measures for explosion protection 5.1 General Priority shall be given to the prevention of the formation of hazardous explosive atmospheres. This can be done by avoiding or reducing the use or by limiting the concentration of flammable substances. Preventing of hazardo
47、us explosive atmospheres can also be realized by inerting. If it is not possible to prevent the formation of a hazardous explosive atmosphere, its ignition shall be avoided. This can be achieved by protective measures which avoid or reduce the probability of ignition sources. The probability that a
48、hazardous explosive atmosphere and a source of ignition will be present at the same place and time is estimated and the extent of the measures required is determined accordingly. This is done on the basis of the zone concept, from which the necessary precautions are derived. NOTE It is, however, rec
49、ognized that there can be sources of ignition that cannot be determined with a high degree of accuracy (e.g. an electrostatic discharge within a pipe or a lightning strike). 5.2 Mitigation of the effects of explosion 5.2.1 General In many cases, it is not possible to avoid explosive atmospheres and sources of ignition with a sufficient degree of certainty. Measures shall then be taken to limit the effects of an explosion to an acceptable extent. Such measures are: explosion-resistant design; explosion relief; explosion
