BS EN 26948-1991 自动凝汽阀生产和性能特点试验规范.pdf

BRITISH STANDARD BS EN 269481991 ISO 69481981 Specification for Production and perance characteristic tests for automatic steam traps The European Standard EN 269481991 has the status of a British Standard BS EN 269481991 This British Standard was published under the authority of the Standards Board and comes into effect on 29 November 1991 BSI 10-1999 The following BSI references relate to the work on this standard Committee reference PSE/7 Draft for comment 79/80385 DC ISBN 0 580 20220 8 Cooperating organizations The European Committee for Standardization CEN, under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries. AustriaOesterreichisches Normungsinstitut BelgiumInstitut belge de normalisation DenmarkDansk Standardiseringsraad FinlandSuomen Standardisoimisliito, r.y. FranceAssociation franaise de normalisation GermanyDeutsches Institut fr Normung e.V. GreeceHellenic Organization for Standardization IcelandTechnological Institute of Iceland IrelandNational Standards Authority of Ireland ItalyEnte Nazionale Italiano di Unificazione LuxembourgInspection du Travail et des Mines NetherlandsNederlands Normalisatie-instituut NorwayNorges Standardiseringsforbund PortugalInstituto Portugus da Qualidade SpainAsociacin Espaola de Normalizacin y Certificacin SwedenStandardiseringskommissionen i Sverige SwitzerlandAssociation suisse de normalisation United KingdomBritish Standards Institution Amendments issued since publication Amd. No.DateComments 标准分享网 w w w .b z f x w .c o m 免费下载 w w w . b z f x w . c o m BS EN 269481991 BSI 10-1999i Contents Page Cooperating organizationsInside front cover National forewordii Foreword2 Text of EN 269483 National appendix NA inativeInside back cover National appendix NB inativeInside back cover w w w . b z f x w . c o m BS EN 269481991 ii BSI 10-1999 National foreword This British Standard has been prepared under the direction of the Piping Systems Components Standards Policy Committee. It is the English language version of EN 269481991 “Automatic steam traps Production and perance characteristic tests” published by the European Committee for Standardization CEN. It supersedes BS 60251982 which is withdrawn. EN 269481991 is identical with ISO 69481981 published by the International Organization for Standardization ISO. A textual error exists in ISO 6948 and in EN 26948. This error has been reported to the Central Secretariat of CEN and the following amendment has been proposed. In 6.7 delete paragraph 2 and insert the following at the end of the clause. “The determination shall be carried out at different pressures within the operating range of the steam trap.” 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, pages i and ii, the EN title page, pages 2 to 6, 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. 标准分享网 w w w .b z f x w .c o m 免费下载 w w w . b z f x w . c o m EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 269481991 October 1991 UDC 621.646.9.057.6621.186.66620.1 Descriptors Valves and fittings, traps drainage, water vapour, steam, automatic equipment, tests, perance tests, perance uation English version Automatic steam traps Production and perance characteristic tests ISO 69481980 Purgeurs automatiques de vapeur d’eau Essais de production et essais des caractristiques de fonctionnement ISO 69481980 Kondensatableiter Fertigungsprfung und Prfung der Funktionsmerkmale ISO 69481980 This European Standard was approved by CEN on 30 September 1991 and is identical to the ISO standard as referred to. 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, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat rue de Stassart 36, B-1050 Brussels CEN 1991 Copyright reserved to all CEN members Ref. No. EN 269481991 E w w w . b z f x w . c o m EN 269481991 BSI 10-1999 2 Foreword On the proposal of the Technical Committee CEN/TC 69 “Industrial Valves” CEN BT decided by resolution C67/1990 to the International Standard ISO 69481981 Automatic steam traps Production and perance characteristic tests to al Vote. This European Standard EN 26948 was approved by CEN on 2 July 1991. According to the Common CEN/CENELEC Rules, 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 and United Kingdom. Contents Page Foreword2 1Scope and field of application3 2References3 3Definitions3 4Production tests3 5Perance characteristic tests3 6Test s4 Table Minimum durations for shell tests4 标准分享网 w w w .b z f x w .c o m 免费下载 w w w . b z f x w . c o m EN 269481991 BSI 10-19993 1 Scope and field of application This International Standard specifies tests applicable to automatic steam traps. These tests, which are hereafter referred to as production tests and perance characteristic tests, may be conducted to ensure the correct functioning of a steam trap or to uate the perance of a particular design. This International Standard specifies the tests to be pered relative to each one of these two categories and describes briefly the corresponding test s. 2 References ISO 6552, Automatic steam traps Terminology. ISO 6553, Automatic steam traps Marking. ISO 6704, Automatic steam traps Classification. 3 Definitions 3.1 production tests those tests carried out by the manufacturer to confirm that each automatic steam trap functions correctly. These tests may be witnessed by the purchaser or his representative; in this case, these tests are referred to as acceptance tests 3.2 perance characteristic tests those tests carried out to determine the operational characteristics of a particular design of steam trap 4 Production tests 4.1 Product inspection Samples of the finished traps shall be visually examined and dimensionally checked to ensure that the traps correspond to the stated specification and are marked in accordance with ISO 6553. 4.2 Shell testing Each steam trap shall be tested to confirm the integrity of its shell under pressure. Further details are given in 6.1. 4.3 Operational check Sample steam traps shall be tested to ensure that they open to discharge condensate and close satisfactorily. Further details are given in 6.2. This test does not apply to the labyrinth or orifice steam traps see ISO 6704. 4.4 Notice for acceptance tests If the purchaser wishes to witness the tests, this shall be specified in the order. If the manufacturer shall give the purchaser at least five days notice of the date when the tests will be pered. 5 Perance characteristic tests A manufacturer may describe the operations of a particular type of steam trap by referring to one or more of the following perance characteristic tests. A brief explanation of the derivation of each characteristic is given below; further details on the appropriate test s are specified in clause 6. 5.1 Minimum operating pressure The steam trap shall be tested to determine the minimum pressure atmospheric or above at which correct opening and closing will occur. 5.2 Maximum operating pressure PMO The steam trap shall be tested to determine the maximum pressure at which correct opening and closing will occur. 5.3 Maximum operating back pressure PMOB The steam trap shall be tested to determine the maximum pressure permissible at the outlet of the device which allows correct functioning. 5.4 Air venting capability The steam trap shall be tested to determine its ability to discharge air. 5.5 Operating temperature TO The steam trap shall be tested to determine the temperature at which the device operates and in particular the temperature at which it passes its specified capacity. 5.6 Condensate capacity QH or QC The steam trap shall be flow tested to determine its condensate capacity throughout its operating pressure range. 5.7 Live steam loss The steam trap shall be tested to determine the amount of live steam lost via the trap. w w w . b z f x w . c o m EN 269481991 4 BSI 10-1999 6 Test s 6.1 Shell testing The test fluid, the choice of which is left to the discretion of the manufacturer, shall be either water, which may contain a corrosion inhibitor, kerosene or any other suitable liquid having a viscosity not greater than that of water; steam, air or any other suitable gas. NOTEVarious statutory authorities require specific approval of test procedures where the test is conducted using steam, air or other gas. Any internal trim which will not withstand the test pressure may be removed before the test. The trap shall be essentially vented of air when testing with a liquid. Traps shall not be painted or otherwise coated with materials capable of sealing against leakage before the shell pressure tests are completed. Chemical corrosion protection treatments and internal linings are permitted. If pressure tests in the presence of a representative of the purchaser are specified, painted traps from stock may be re-tested without removal of paint. Test equipment shall not subject the trap to externally applied stresses which may affect the results of the tests. The shell test shall be pered by applying pressure inside the assembled trap with the ends closed. For all traps, the hydraulic shell test shall be pered at a pressure 1,5 times the maximum allowable pressure at 20 C. For traps with a nominal diameter less than or equal to DN 50 in the pressure range up to PN 50, the shell test may be carried out either using liquid at a pressure equal to 1,5 times the maximum allowable pressure at 20 C or using gas at a pressure gauge pressure of 6 bar 0,6 Mpa. Visually detectable leakage through the pressure retaining walls is not acceptable. Test durations shall not be less than those specified in the Table. Table Minimum durations for shell tests 6.2 Operational check The steam trap shall be fed with steam, and condensate shall be introduced intermittently. When only steam is present, the steam trap shall close; on the introduction of condensate, the steam trap shall open the time taken will vary as a function of the steam trap type; when the condensate has been discharged, the steam trap shall again close. The test is complete when at least one complete cycle has been pered. Certain types of trap may be tested with air or water. 6.3 Determination of minimum operating pressure Operational checks, as described in 6.2, shall be carried out whilst successively reducing the test pressure until the steam trap fails to open and close correctly. The minimum operating pressure is the lowest test pressure at which correct operation is observed. 6.4 Determination of maximum operating pressure The maximum operating pressure of the steam trap may be verified by carrying out operational checks, as described in 6.2, whilst successively increasing the test pressure up to the steam trap’s maximum operating pressure. The steam trap shall open and close correctly throughout the test. 6.5 Determination of maximum operating back pressure Operational checks, as described in 6.2, shall be carried out with the outlet from the steam trap connected to a vessel in which the pressure can be raised, independent of the test pressure upstream of the steam trap. Whilst maintaining a reference pressure at the steam trap’s inlet, the pressure at its outlet is to be raised successively until the steam trap fails to open and close correctly. The maximum operating back pressure is the highest pressure applied to the steam trap’s outlet at which correct operation is still observed. Nominal trap size DN Minimum test duration s DN u 5015 65 u DN u 20060 250 u DN180 标准分享网 w w w .b z f x w .c o m 免费下载 w w w . b z f x w . c o m EN 269481991 BSI 10-19995 6.6 Air venting capability test Air shall be introduced at a specified temperature into the trap or upstream piping. The air venting capability shall be checked by an air flow measurement carried out at minimum and maximum operating pressures, the temperature inside the trap being recorded. 6.7 Determination of operating temperature Steam shall be fed into the steam trap to effect closure. Condensate, at saturated steam temperature, shall then be introduced and, unless the steam trap opens immediately, shall be allowed to cool slowly at the steam trap’s inlet. The temperature of the condensate, measured at the steam trap’s inlet, at which the device opens, is the operating temperature. The operating temperatures are the temperatures of the condensate, measured at the inlet to the trap, at which the trap passes its specified capacities. 6.8 Condensate capacity test The capacity of the steam trap shall be determined by measuring the amount of condensate that is discharged from the device under specified conditions of pressure differential and condensate temperature. The test shall be carried out with condensate at different temperatures and at different pressures within the steam trap’s operating range to be specified in a forthcoming International Standard. 6.9 Determination of live steam loss Several s may be used to determine the amount of live steam lost, if any, by the steam trap in accordance with a forthcoming International Standard. w w w . b z f x w . c o m 6 blank 标准分享网 w w w .b z f x w .c o m 免费下载 w w w . b z f x w . c o m BS EN 269481991 BSI 10-1999 National appendix NA inative The United Kingdom participation in the preparation of th