【BS英國標準】BS EN 961-1996 Gas welding equipment — Manifold regulators used in welding, cutting and allied processes up to 200 bar.doc

british standard bs en961:1996gas welding equipment manifold regulatorsused in welding, cutting and allied processes up to 200 barthe european standard en 961:1995 has the status of abritish standardics 23.060.40; 25.160.10bs en 961:1996committees responsible for thisbritish standardthe preparation of this british standard was entrusted to technical committee wee/18, gas welding and cutting appliances, upon which the following bodies were represented:british compressed gases associationbritish railways boardconsumer policy committee of bsi health and safety executivelp gas associationrailway industry associationsouth bank universitywelding manufacturers association (beama ltd.)this british standard, having been prepared under the direction of the engineering sector board, was published under the authority of the standards board and comes into effect on15 april 1996 bsi 11-1999the following bsi references relate to the work on this standard:committee reference wee/18draft for comment 92/86390 dcisbn 0 580 23731 1amd. no.datecommentsamendments issued since publicationbs en 961:1996contentspage committees responsibleinside front cover national forewordii foreword 2text of en 9613list of referencesinside back cover bsi 11-1999ibs en 961:1996national forewordthis british standard has been prepared by technical committee wee/18, and is the english language version of en 961:1995 gas welding equipment manifold regulators used in welding, cutting and allied processes up to 200 bar published by the european committee for standardization (cen).it is assumed that the execution of the provision of the document is entered to suitably qualified and experienced persons.cross-referencespublication referred to corresponding british standarden 562:1994bs en 562:1995 gas welding equipment. pressure gauges used in welding, cutting and allied processesen 585:1994bs en 585:1995 gas welding equipment. pressure regulators for gas cylinders used in welding, cutting and allied processes up to 200 baren 29090:1992bs en 29090:1992 specification for gas tightness of equipment for gas welding and allied processesen 29539:1992bs en 29539:1992 specification for materials for equipment used in gas welding, cutting and allied processesa 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 pagesthis document comprises a front cover, an inside front cover, pages i and ii, the en title page, pages 2 to 14, an inside back cover and a back cover.this standard has been updated (see copyright date) and may have had amendments incorporated. this will be indicated in the amendment table on the inside front cover. bsi 11-1999iieuropean standard norme europenneeuropische normen 961august 1995ics 23.060.40; 25.160.10descriptors: welding equipment, gas welding, gas cutting, compressed gas, acetylene, pressure regulators, gas cylinders, specifications, design, safety, equipment specifications, performance evaluation, tests, markingenglish versiongas welding equipment manifold regulators used in welding, cutting and allied processes up to 200 barmatriel de soudage aux gaz dtendeurs des centrales de bouteilles (de gaz industriels) pour le soudage, le coupage et les techniques connexes jusqu 200 bargasscheweigerte haupstellendruckregler fr schweien, schneiden und verwandte verfahren bis 200 barthis european standard was approved by cen on 1995-04-08. 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 cen central secretariat has the same status as the official versions.cen members are the national standards bodies of austria, belgium, denmark, finland, france, germany, greece, iceland, ireland, italy, luxembourg, netherlands, norway, portugal, spain, sweden, switzerland and united kingdom.ceneuropean committee for standardization comit europen de normalisation europisches komitee fr normungcentral secretariat: rue de stassart 36, b-1050 brussels 1995 all rights of reproduction and communication in any form and by any means reserved in all countries to cen and its members.ref. no. en 961:1995 een 961:1995forewordthis european standard has been prepared by subcommittee 7, equipment for gas welding, cutting and allied processes, of technical committee cen/tc 121, welding, of which the secretariat is held by ds.it is based on iso 7291:1990 welding, cutting and allied processes manifold regulators, but amended considering en 585 on pressure regulators for gas cylinders up to 200 bar.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 1996, and conflicting national standards shall be withdrawn at the latest by february 1996.in accordance with the cen/cenelec internal regulations, the following countries are bound to implement this european standard: austria, belgium, denmark, finland, france, germany, greece, iceland, ireland, italy, luxembourg, netherlands, norway, portugal, spain, sweden, switzerland, united kingdom.contents9markingpage129.1regulator129.2relief valve12annex a (informative) decomposition test for manifold regulators used for acetylene13figure 1 typical dynamic expansion curves4figure 2 flow rate characteristics4figure 3 manifold regulator5figure 4 allowable internal leakage rates8figure 5 example of test set-up for the measurement of the maximum flow rate, qmax8figure 6 example of test set-up forplotting the dynamic curve for outlet pressure9figure 7 test bench for ignition test11figure 8 test interval12figure a.1 test bench for decomposition test13table 1 conversion coefficients, u5table 2 pressure7table 3 test pressures11table 4 code letters for gases to be used for marking of regulators12page1scope32normative references33definition34physical characteristics34.1pressures34.2flow rates34.3coefficients35units45.1pressures45.2flow rate45.3temperatures46design and safety requirements56.1general56.2design requirements56.3functional characteristics67type tests77.1general test conditions77.2performance and functional tests77.3mechanical tests107.4leakage tests107.5ignition test for oxygen manifold regulators108instruction for use11foreword213 bsi 11-19991 scopethis standard specifies requirements and test methods for manifold regulators for welding, cutting and allied processes.it is applicable to regulators normally used for compressed gases up to 200 bar (20 mpa), for dissolved acetylene,methylacetylene-propadiene-mixtures (mps) and carbon dioxide (co2), to regulate the pressure at the outlet of high-pressure lines from manifold gas cylinders.it is not applicable to regulators fitted directly to the gas cylinders, as defined in en 585 or to regulators for liquefied petroleum gases.2 normative referencesthis 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 revision 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.en 562, gas welding equipment pressure gauges used in welding, cutting and allied processes.en 585, gas welding equipment pressure regulators for gas cylinders used in welding, cutting and allied processes up to 200 bar.en 29090, gas tightness of equipment for gas welding and allied processes.(iso 9090:1989)en 29539, materials for equipment used in gas welding, cutting and allied processes.(iso 9539:1988)iso 554:1976, standard atmospheres for conditioning and/or testing specifications.3 definitionfor the purposes of this standard, the following definition applies.3.1manifold regulatordevice for regulating a generally variable inlet pressure to as constant as possible an outlet pressure, and intended to equip a manifold of cylinders4 physical characteristics4.1 pressures4.1.1 nominal (maximum) inlet pressure, p1nominal (maximum) upstream pressure for which the manifold regulator is designed.4.1.2 nominal (maximum) outlet pressure, p2nominal (maximum) downstream pressure corresponding to the nominal discharge, q1, indicated by the manufacturer.4.1.3 upstream pressure for type testing, p3the pressure, in bar, given by the equation:p3 = 2p2 + 1 bar.4.1.4 stabilized outlet pressure; stabilization pressure, p4the pressure recorded 1 min after discharge ceases, with the pressure regulator set to the standard initial conditions p2, p3, q highest or lowest outlet pressure, p5the highest or lowest value of the outlet pressure during the test for i in which the inlet pressure varies from p1 to p3 for a flow equal to the nominal discharge q1 indicated by the manufacturer(see figure 1).4.2 flow rates4.2.1 maximum discharge, qmaxthe maximum flow rate obtained at pressures p3 and p2. at these conditions the stabilized outlet pressure p4 shall not exceed the allowable value given in 4.3.1 (see figure 2):4.2.2 nominal discharge, q1the maximum flow rate for the manifold regulator defined by the manufacturer for a particular gas (see figure 2). q1 may not be less than 0,5 qmax.4.3 coefficients4.3.1 coefficient of pressure increase upon closure, rthe coefficient given by the equation:42p pr = -p2for acetylene regulator p2 = p2r. the resulting value shall be in conformity with r k 0, irregularity coefficient, ithe coefficient given by the equation:-22ii = p5 p2- for acetylene regulator p = p .p2the resulting value shall be in conformity with 0,3 k i k + 0,5.figure 1 typical dynamic expansion curvesfigure 2 flow rate characteristics5 units5.1 pressuresconversion coefficient, u, based on the formula:0pressures specified in this standard are gauge pressures1). they are expressed in bar (or in pascals or multiples thereof) at normal conditions2).u =where-15.2 flow rateflow rates are measured in cubic metres per hour (m3/h) at normal conditions2) taking into account the corrections for the relevant gas (see table 1).0 is the specific weight of the gas;1 is the specific weight of gas used.5.3 temperaturestemperatures are measured in degrees celsius.1) pressure exceeding the atmospheric pressure.2) nominal conditions are: 23c and 1,013 bar (0,1013 mpa) according to iso 554.table 1 conversion coefficients, utest gasconversion coefficientairoxygennitrogenargonhydrogenheliumacetyleneco2air10,9501,020,8523,812,6951,050,809nitrogen0,9830,93010,8373,752,651,030,792figure 3 manifold regulator6 design and safety requirements6.1 generalfigure 3 shows a manifold regulator as an illustration only. optional design characteristics shall be compatible with the safety requirements specified in this standard.6.2 design requirements6.2.1 materialsmaterials used for the construction of regulators shall comply with the requirements specified in en 295 design and manufacture oxygen manifold regulatorsoxygen manifold regulators shall be so designed, machined and assembled as to avoid the risk of internal burning and shall comply with the requirements specified in 7.5. all components and accessories shall be thoroughly cleaned and degreased before assembly. acetylene manifold regulatorsmanifold pressure regulators used for acetylene shall be designed and constructed in such a way that they withstand a decomposition of acetylene.the test can be carried out in accordance withannex a. other equivalent tests can also be used. filtera dust filter having an effective cross-section compatible with the discharge shall be mounted within or directly fitted to the pressure regulator upstream of the pressure regulator valve. the filter shall retain particles greater than or equalto 0,1 mm. inlet connectionschoice of inlet connections for manifold regulators is left to the manufacturers discretion.if cylinder valve connections are used, they shall conform to the relevant national standard. outlet connectionschoice of outlet connection is left to the manufacturers discretion. pressure regulator coverthe manifold regulator shall be designed and assembled in such a way that, if the low pressure chamber or the intermediate chamber (in the case of a two-stage regulator) is subjected to direct full cylinder pressure, for example if the regulator valve is jammed in the open position or if the outlet union is closed (for example by a valve or a seal), high pressure gas is either contained or is vented safely without ejecting component parts.pneumatically controlled regulators, in which the diaphragm is held by the pressure of the control gas, shall comply with the safety requirements. relief valve.1 generalall manifold regulators shall be supplied with a relief valve designed to vent excess outlet pressure.note acetylene regulators are excluded from the requirement for a relief valve to allow for alternative safety systems, for example safety shut-off valves operating upstream of the regulator..2 locationthe relief valve shall be fitted downstream of the regulator valve.the relief valve may be fitted on the regulator or be supplied as a separate unit for installation downstream of the regulator outlet.the relief valve shall be designed to allow venting of the gas into a vent pipe of a diameter equal to or greater than the relief valve seat orifice..3 operationthe relief valve shall be tight against a pressure greater than the maximum pressure attained when the flow rate is set for the initial pressure, p2, plus an overpressure corresponding to the real coefficients i and r.when the gas to be vented is at a pressure of 2p2, the flow rate of the relief valve shall be equal to at least half the nominal discharge q1 (u 0,5 q1), of the manifold regulator.during its response, when the pressure falls, the relief valve shall seal when the downstream pressure is again equal or slightly superior to the maximum value, p2.note relief valves conforming to this standard may not provide adequate safety against excess pressure for all manifold systems. designers and installers of manifold systems should consider if additional relief valves are necessary. pressure gaugesmanifold regulators shall be fitted with pressure measuring devices complying with the functions and safety requirements specified in en 562. upstream pressure gauges shall form an integral part of the regulator or they shall be fitted to the manifold.downstream pressure gauges shall be fitted directly to the regulator or close to the latter.gauges fitted downstream shall satisfy the requirements resulting from a possible pressure rise due to the coefficients i and r. pressure-adjusting devicethis device shall be designed in such a way that it is not possible for the pressure regulator valve to be held in the open position, for example as a consequence of the spring going solid.if the dimensions of the pressure-adjusting screw are essential for the safe operation of the manifold regulator, then the pressure-adjusting screw shall not be removable.the movement of the pressure-adjusting screw of acetylene manifold regulators shall be restricted, in order to obtain a maximum permissible nominal outlet pressure, p2 (see table 2).6.3 functional characteristics6.3.1 mechanical resistance fitness for servicemanifold regulators shall be designed and constructed in such a way that the application of pressures given in 7.3