BS-EN-12078-1998.pdf
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 12078:1998 The European Standard EN 12078:1998 has the status of a British Standard ICS 23.060.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Zero governors for gas burners and gas burning appliances Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 15:02:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 12078:1998 This British Standard, having been prepared under the direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 December 1998 BSI 1998 ISBN 0 580 30375 6 Amendments issued since publication Amd. No.DateText affected National foreword This British Standard is the English language version of EN 12078:1998. The UK participation in its preparation was entrusted by Technical Committee GSE/22, Safety and control devices for gas governors and gas burning appliances, to Subcommittee GSE/22/19, Gas/air ratio controls, which has the responsibility to: Ð aid enquirers to understand the text; Ð present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; Ð monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled ªInternational Standards Correspondence Indexº, or by using the ªFindº facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 15 and a back cover. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 15:02:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN European Committee for Standardization Comite  Europe Âen de Normalisation Europa Èisches Komitee fu Èr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12078:1998 E EUROPEAN STANDARDEN 12078 NORME EUROPE ÂENNE EUROPA ÈISCHE NORM August 1998 ICS 23.060.40 Descriptors: gas appliance burners, pressure regulators, definitions, safety, equipment specifications, materials, junctions, dimensions, performance evaluation, durability, tests, leak tests, performance tests, marking, technical notices English version Zero governors for gas burners and gas burning appliances De Âtendeurs a Á ze Âro pour bru Ãleurs a Á gaz et appareils a Á gaz Nulldruckregler fu Èr Gasbrenner und Gasgera Ète This European Standard was approved by CEN on 26 July 1998. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 15:02:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 2 EN 12078:1998 BSI 1998 Foreword This European Standard has been prepared by Technical Committee CEN/TC 58, Safety and control devices for gas-burners and gas-burning appliances, the Secretariat of which is held by BSI. 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 February 1999, and conflicting national standards shall be withdrawn at the latest by February 1999. This European Standard 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(s). For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this standard. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Contents Page Foreword2 1Scope3 2Normative references3 3Definitions3 4Units of measurement4 5Construction requirements4 5.1General4 5.2Materials5 5.3Connections5 5.4Seals for glands for moving parts6 5.5Pressure test nipples6 6Performance requirements6 6.1General6 6.2External leak-tightness6 Page 6.3Torsion and bending6 6.4Durability7 6.5Zero governor performance8 6.6Endurance8 6.7Lock-up pressure8 6.8Response time8 7Test methods8 7.1Mounting position8 7.2Test conditions8 7.3External leak-tightness8 7.4Torsion and bending8 7.5Durability10 7.6Zero governor performance test10 7.7Pressure drop (fully open)13 7.8Endurance13 7.9Lock-up pressure13 7.10 Dynamic response test13 8Marking, installation and operating instructions13 8.1Marking13 8.2Installation, operating and servicing instructions13 8.3Warning notice13 Annex ZA (informative) Clauses of this European Standard addressing essential requirements or other Provisions of EU Directives14 Table 1 Ð Connection sizes6 Table 2 Ð Maximum external leakage rates6 Table 3 Ð Torque and bending moment7 Table 4 Ð Gas pressure at inlet to the zero governor8 Figure 1 Ð Arrangement for torsion test9 Figure 2 Ð Arrangement for bending moment test9 Figure 3 Ð Paint scratch test apparatus10 Figure 4 Ð Performance test rig11 Figure 5 Ð Characteristics of p2as p1 varies12 Figure 6 Ð Characteristics of p2as q varies12 Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 15:02:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 3 EN 12078:1998 BSI 1998 1 Scope This standard specifies the safety, constructional and performance requirements for zero pressure governors, hereafter referred to as zero governors, intended for use with gas appliances. It also gives the test procedures for evaluating these requirements and information necessary for the purchaser and user. This standard applies to zero governors for gas-burning appliances that may be used and tested independently of these appliances. These zero governors are suitable for one or more of the fuel gases of the 1st, 2nd and 3rd families, at inlet pressures up to and including 200 mbar. This standard does not cover: a) zero governors connected directly to distribution pipework or to a container that maintains a standard distribution pressure; b) zero governors intended for gas appliances to be installed out-of-doors and exposed to the environment. This standard covers type testing only. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. ISO 7-1:1994, Pipe threads where pressure-tight joints are made on the threads Ð Part 1: Dimensions, tolerances and designation. ISO 65:1981, Carbon steel tubes suitable for screwing in accordance with ISO 7-1. ISO 68:1973, ISO general purpose screw threads. Basic profile. ISO 228-1:1994, Pipe threads where pressure-tight joints are not made on the threads Ð Part 1: Dimensions, tolerances and designation. ISO 262:1973, ISO general purpose metric screw threads Ð Selected sizes for screws, bolts and nuts. ISO 274:1975, Copper tubes of circular section Ð Dimensions. ISO 301:1981, Zinc alloy ingots intended for casting. ISO 1817:1985, Rubber, vulcanized Ð Determination of the effect of liquids. ISO 7005, Metallic flanges. EN 60730-1:1995, Automatic electrical controls for household and similar use Ð Part 1: General requirements. 3 Definitions For the purposes of this standard, the following definitions apply. 3.1 zero governor (atmospheric pressure regulator) device which maintains the outlet pressure constant at a value equal to or close to atmospheric pressure independent of the variations in the inlet pressure and/or flow rate within defined limits 3.2 pressures 3.2.1 inlet pressure (p1) pressure at the inlet of the zero governor 3.2.2 outlet pressure (p2) pressure at the outlet of the zero governor 3.2.3 test pressure pressure to be applied during a test 3.2.4 pressure drop pressure difference between the inlet and the outlet pressure with the zero governor valve open to its fullest extent 3.2.5 maximum inlet pressure (p1max) highest inlet pressure declared by the manufacturer 3.2.6 minimum inlet pressure (p1min) lowest inlet pressure declared by the manufacturer 3.2.7 inlet pressure range range of inlet pressures between the maximum and minimum values 3.2.8 setting point this refers to the inlet and outlet pressures declared by the manufacturer, at which the zero governor is initially adjusted for test purposes (see 6.5.1 and 7.6.3) at a declared flow rate. The respective pressures and flow rate are termed ªinlet setting pressureº, ªoutlet setting pressureº and ªsetting flow rateº 3.3 flow rates 3.3.1 maximum flow rate (qmax) maximum rate, as a function of inlet and outlet pressures, declared by the manufacturer and expressed in m3/h of air at standard conditions. For a non-adjustable zero governor there is only one maximum flow rate Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 15:02:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 4 EN 12078:1998 BSI 1998 1) 1 mbar = 100 N/m2= 100 Pa. 3.3.2 minimum flow rate (qmin) minimum rate, as a function of inlet and outlet pressures, declared by the manufacturer and expressed in m3/h of air at standard conditions. For a non-adjustable zero governor there is only one minimum flow rate 3.3.3 flow rate range range of flow rates between the maximum and minimum values 3.3.4 setting flow rate see 3.2.8 3.4 component parts 3.4.1 breather hole orifice that allows atmospheric pressure to be maintained in a compartment of variable volume 3.4.2 diaphragm flexible member which, under the influence of the forces arising from loading and pressure, operates the zero governor valve 3.5 performance terms 3.5.1 external leak-tightness (soundness) leak-tightness of a gas-carrying compartment with respect to atmosphere 3.5.2 lock-up pressure outlet pressure at which a zero governor closes when the outlet of the governor is sealed. The increase in outlet pressure is expressed in mbar 3.5.3 maximum ambient temperature highest temperature of the surrounding air, declared by the manufacturer at which the zero governor may be operated 3.5.4 minimum ambient temperature lowest temperature of the surrounding air, declared by the manufacturer at which the zero governor may be operated 3.5.5 mounting position position declared by the manufacturer for mounting the zero governor 3.6 response time the maximum time taken for the output to reach stable conditions in response to a change in inlet pressure 3.7 classification (see Table 3) 3.7.1 group 1 a zero governor for use in an appliance and/or installation where it is not subjected to bending stresses imposed by installation pipework, e.g. by the use of rigid adjacent supports 3.7.2 group 2 a zero governor for use in any situation, either internal or external to the appliance, typically without supports. NOTEA zero governor which meets the requirements of group 2 also meets the requirements for group 1. 4 Units of measurement 4.1 All dimensions are given in millimetres. 4.2 All pressures are static pressures relative to atmospheric pressure and are expressed in millibars1). 4.3 Bending moment and torques are given in newton metres. 5 Construction requirements 5.1 General 5.1.1 Zero governors shall be designed, manufactured and assembled so that they function correctly when installed and used according to the manufacturer's instructions. 5.1.2 All parts of a zero governor shall be free from sharp edges and corners which might cause damage, injury or incorrect operation. 5.1.3 Holes for screws, pins, etc., which are used for the assembly of parts of the zero governor and for mounting, shall not penetrate gasways. The wall thickness between these holes and gasways shall be at least 1 mm. 5.1.4 Holes necessary in manufacture which connect gasways to atmosphere but which do not affect the operation of the zero governor shall be permanently sealed by metallic means. Suitable jointing compounds may additionally be used. 5.1.5 Closure parts, including those of measuring and test points, which may be dismantled for servicing, adjustment or conversion, shall be constructed such that leak-tightness in accordance with 7.3 is achieved by mechanical means (e.g. metal to metal joints, O-rings). This excludes all jointing compounds such as liquids, pastes and tapes. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 15:02:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 5 EN 12078:1998 BSI 1998 Jointing compounds, may be used for permanent assemblies and shall remain effective under normal operating conditions. Closure parts not intended to be dismantled during servicing, adjustment or conversion shall be sealed by means which will show evidence of interference (e.g. lacquer). 5.1.6 Parts that require dismantling, e.g. for servicing, shall be capable of being dismantled and reassembled using commonly available tools and shall be constructed or marked such that incorrect assembly is impossible when following the manufacturer's instructions. 5.1.7 Screwed fastenings that may be removed during servicing shall have metric
