1、BRITISH STANDARDBS EN 12953-9:2007Shell boilers Part 9: Requirements for limiting devices of the boiler and accessoriesThe European Standard EN 12953-9:2007 has the status of a British StandardICS 27.060.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g4
2、9g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 12953-9:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2007 BSI 2007ISBN 978 0 580 58655 2National forewordThis Bri
3、tish Standard is the UK implementation of EN 12953-9:2007.The UK participation in its preparation was entrusted to Technical Committee PVE/2, Water tube and shell boilers.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purpo
4、rt to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 1295
5、3-9July 2007ICS 27.060.30English VersionShell boilers - Part 9: Requirements for limiting devices of theboiler and accessoriesChaudires tubes de fume - Partie 9: Exigences pourles dispositifs de limitation de la chaudire et de sesaccessoiresGrowasserraumkessel - Teil 9: Anforderungen anBegrenzungsei
6、nrichtungen an Kessel und ZubehrThis European Standard was approved by CEN on 26 May 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lis
7、ts and bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the respon
8、sibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Icelan
9、d, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassa
10、rt, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12953-9:2007: EEN 12953-9:2007 (E) 2 Contents Page Foreword 4 1 Scope 6 2 Normative references 6 3 Terms and definitions . 7 4 Requirements for limiter . 9 4
11、.1 General 9 4.2 Materials and design . 9 4.3 Electrical equipment 10 4.4 Fault assessment. 10 4.5 Marking . 12 5 Special requirements for water level limiters .14 5.1 Components. 14 5.2 Design . 14 5.3 Floating devices. 15 5.4 Level electrode devices 15 5.5 Examination of functional capability . 16
12、 5.6 Fault detection . 19 6 Special requirements for pressure limiters 19 6.1 Components. 19 6.2 Additional fault assessment requirements .19 6.3 Design . 19 6.4 Electrical equipment 20 6.5 Examination of functional capability . 20 6.6 Fault detection . 22 7 Special requirements for temperature limi
13、ters. 22 7.1 Components. 22 7.2 Design . 22 7.3 Electrical equipment 24 7.4 Examination of functional capability . 24 8 Special requirements for flow limiters. 25 8.1 Components. 25 8.2 Design . 25 8.3 Electrical equipment 25 8.4 Examination of functional capability . 25 Annex A (informative) Limiti
14、ng device 26 Annex B (informative) Example of an examination plan . 27 Annex C (informative) Marking of limiters 29 Annex D (normative) Immunity against electrical and electromagnetic influences Requirements and testing. 32 D.1 General 32 D.2 Immunity against mains voltage variations 32 D.3 Immunity
15、 against short-time voltage interruptions and reductions. 32 D.4 Immunity against mains frequency changes 33 D.5 Immunity against electrostatic discharge (ESD) 33 D.6 Immunity against fast transient disturbance variables (burst). 33 D.7 Immunity against surges 34 D.8 Immunity against high-frequency
16、electromagnetic fields. 34 D.9 Immunity against conducted disturbances induced by high frequency fields. 35 D.10 Immunity against power frequency magnetic fields 35 EN 12953-9:2007 (E) 3 Annex ZA (informative) Relationship between this European Standard and the Essential Requirements of EU Directive
17、 97/23/EC 36 Bibliography 37 EN 12953-9:2007 (E) 4 Foreword This document (EN 12953-9:2007) has been prepared by Technical Committee CEN/TC 269 “Shell and water-tube boilers”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by
18、publication of an identical text or by endorsement, at the latest by January 2008 and conflicting national standards shall be withdrawn at the latest by January 2008. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and
19、supports essential requirements of EU Directive(s). For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document. The European Standard EN 12953 concerning shell boilers consists of the following Parts: Part 1: General Part 2: Materials for pressure par
20、ts of boilers and accessories Part 3: Design and calculation for pressure parts Part 4: Workmanship and construction of pressure parts of the boiler Part 5: Inspection during construction, documentation and marking of pressure parts of the boiler Part 6: Requirements for equipment for the boiler Par
21、t 7: Requirements for firing systems for liquid and gaseous fuels for the boiler Part 8: Requirements for safeguards against excessive pressure Part 9: Requirements for limiting devices of the boiler and accessories Part 10: Requirements for feedwater and boiler water quality Part 11: Acceptance tes
22、ts Part 12: Requirements for grate firing systems for solid fuels for the boiler Part 13: Operating instructions CR 12953 Part 14: Guideline for the involvement of an inspection body independent of the manufacturer. Although these Parts may be obtained separately, it should be recognised that the Pa
23、rts are interdependent. As such, the design and manufacture of shell boilers requires the application of more than one Part in order for the requirements of the European Standard to be satisfactorily fulfilled. According to the CEN/CENELEC Internal Regulations, the national standards organizations o
24、f the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slo
25、vakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 12953-9:2007 (E) 5 Introduction The types of limiters which shall be fitted to boilers are specified in EN 12953-6 and the design of the safety systems are specified in EN 50156-1. A limiter (or limiting device) is one element of a s
26、hell boiler safety system. It comprises a sensor and monitoring elements to achieve the desired level of reliability. In order to provide the necessary safety function, for example, to cut off the heat supply to the boiler in the event of a low water fault, the limiter is connected to other elements
27、 in the safety system such as actuators and safety logic circuits. EN 12953-9:2007 (E) 6 1 Scope This European Standard specifies requirements for limiters (or limiting devices) which are incorporated into safety systems for shell boilers as defined in EN 12953-1. A limiter (or limiting device) can
28、be either: a safety accessory as defined in the Pressure Equipment Directive, Article 1, clause 2.1.3, and needs to include the safety logic and final actuator, or one element of a safety system, for example, a self-monitoring water level sensor used as part of a safety accessory as defined in the P
29、ressure Equipment Directive, Article 1, clause 2.1.3. The overall boiler protection function needs to be provided in association with additional safety logic (where appropriate) and a final actuator. The design requirements and examination of functional capability for the limiters are covered in thi
30、s European Standard. For an explanation of the extent of the limiter (or limiting device) see Figure A.1. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, th
31、e latest edition of the referenced document (including any amendments) applies. EN 298:2003, Automatic gas burner control systems for gas burners and gas burning appliances with or without fans EN 50156-1:2004, Electrical equipment for furnaces and ancillary equipment Part 1: Requirements for applic
32、ation design and installation EN 60529:1991, Degrees of protection provided by enclosures (IP code) (IEC 60529:1989) EN 60664-1:2003, Insulation coordination for equipment within low-voltage systems Part 1: Principles, requirements and tests (IEC 60664-1:1992 + A1:2000 + A2:2002) EN 60730-1:2000, Au
33、tomatic electrical controls for household and similar use Part 1: General requirements (IEC 60730-1:1999, modified) EN 61000-4-2:1995, Electromagnetic compatibility (EMC) Part 4: Testing and measurement techniques Section 2: Electrostatic discharge immunity test Basic EMC publication (IEC 61000-4-2:
34、1995) EN 61000-4-3:2006, Electromagnetic compatibility (EMC) Part 4-3: Testing and measurement techniques Radiated, radio-frequency, electromagnetic field immunity test (IEC 61000-4-3:2006) EN 61000-4-4:2004, Electromagnetic compatibility (EMC) Part 4-4: Testing and measurement techniques Electrical
35、 fast transient/burst immunity test (IEC 61000-4-4:2004) EN 61000-4-5:2006, Electromagnetic compatibility (EMC) Part 4: Testing and measurement techniques Section 5: Surge immunity test (IEC 61000-4-5:2005) EN 61000-4-6:1996, Electromagnetic compatibility (EMC) Part 4: Testing and measurement techni
36、ques Section 6: Immunity to conducted disturbances, induced by radio-frequency fields (IEC 61000-4-6:1996) EN 61000-4-8:1993, Electromagnetic compatibility (EMC) Part 4: Testing and measurement techniques Section 8: Power frequency magnetic field immunity test; basic EMC publication (IEC 61000-4-8:1
37、993) EN 12953-9:2007 (E) 7 EN 61000-4-11:2004, Electromagnetic compatibility (EMC) Part 4-11: Testing and measurement techniques Voltage dips, short interruptions and voltage variations immunity tests (IEC 61000-4-11:2004) EN 61000-6-2:2005, Electromagnetic compatibility (EMC) Part 6-2: Generic stan
38、dards Immunity for industrial environments (IEC 61000-6-2:2005) EN 61508-3:2001, Functional safety of electrical/electronic/programmable electronic safety-related systems Part 3: Software requirements (IEC 61508-3:1998 + Corrigendum 1999) 3 Terms and definitions For the purposes of this document, th
39、e following terms and definitions apply. 3.1 limiter limiting device that, on reaching a fixed value (e.g. pressure, temperature, flow, water level) is used to interrupt and lock-out the energy supply NOTE Limiting device comprises: a measuring or detection function and an activation function for co
40、rrection, or shutdown, or shutdown and lockout, and which is used to carry out safety related functions as defined in the PED, on its own or as part of a safety (protective) system (e.g. sensors, limiters) (see also Figure 1). If this is achieved by multi channel systems, then all items or limiters
41、for safety purposes are included within the safety (protective) system Figure 1 Protective devices and safety accessories according to Directive 97/23/EC (PED) 3.2 actuating element component which produces changes in other electrical circuits or volume flows (e.g. fuel, air) as a result of the effe
42、ct of changes in signal NOTE For example, a gas shut off valve is not an actuating element. 3.3 fail-safe limiter is fail-safe if it possesses the capability of remaining in a safe condition or transferring immediately to another safe condition in the event of certain faults occurring EN 12953-9:200
43、7 (E) 8 3.4 self-monitoring regular and automatic determination that all chosen components of a safety system are capable of functioning as required 3.5 redundancy provision of more than one device or system which, in the event of a fault, will still be provided by the necessary facilities 3.6 diver
44、sity provision of different means of performing the required function, e.g. other physical principles or other ways of solving the same problem 3.7 complex electronics assemblies which use electronic components with more than one functional output 3.8 safety shut-down process which is effected immed
45、iately following the detection of a fault within the limiter or caused by exceeding the threshold of the process value limit resulting in a defined state with deactivated terminals of the safety output(s) 3.9 lock-out safety shut-down condition of the limiter, such that a restart can only be accompl
46、ished by a manual reset of the limiter or by a manual reset of the safety logic and by no other means NOTE This will be achieved by a competent operator taking account of the physical situation 3.10 sensor transducer which, on reaching a defined limit value, outputs a signal and/or cuts out and only
47、 reverses the output signal in the event of a specific change in the performance quantity (e.g. pressure, temperature, flow, level) NOTE Sensors are used for signalling or for triggering control processes EN 12953-9:2007 (E) 9 4 Requirements for limiter 4.1 General 4.1.1 The requirements set out bel
48、ow have been established to ensure uniform assessment of different devices. A limiter shall be such that a single fault in any related part shall not lead to a loss of the safety function. This shall be achieved by fault avoidance techniques such as self-monitoring with redundancy, diversity or a co
49、mbination of these methods. Fault assessment for the electrical components shall be in accordance with 4.4. The fault assessment chart, see Figure 2 shall also be applied for faults in hydraulic, pneumatic and mechanical components. NOTE The various elements of limiters are given in Annex A. 4.1.2 Limiters shall function independently of each other and of controls unless their safety function cannot be affected by other such functions. Manual resetting can be realised as a part of the limiter or as
