00257495 PDF BRITISH STANDARD BS EN 27842 1991 ISO 7842 1988 Methods for Determination of discharge capacity of automatic steam traps The European Standard EN 27842 1991 has the status of a British St[.]
BRITISH STANDARD Methods for Determination of discharge capacity of automatic steam traps The European Standard EN 27842:1991 has the status of a British Standard BS EN 27842:1991 ISO 7842:1988 BS EN 27842:1991 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 This British Standard was published under the authority of the Standards Board and comes into effect on 29 November 1991 © BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference PSE/7 Draft for comment 85/72012 DC ISBN 580 20222 Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y France Association franỗaise de normalisation Germany Deutsches Institut fỹr Normung e.V Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portuguès da Qualidade Spain Asociación Espola de Normalización y Certificación Sweden Standardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom British Standards Institution Amendments issued since publication Amd No Date Comments BS EN 27842:1991 Contents Cooperating organizations National foreword Foreword Text of EN 27842 National appendix NA (informative) National appendix NB (informative) © BSI 11-1999 Page Inside front cover ii 14 Inside back cover i BS EN 27842:1991 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 27842:1991 “Automatic steam traps — Determination of discharge capacity — Test methods” published by the European Committee for Standardization (CEN) It supersedes BS 6028:1990 which is withdrawn EN 27842:1991 is identical with ISO 7842:1988 published by the International Organization for Standardization (ISO) A British Standard does not purport to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 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 ii © BSI 11-1999 EUROPEAN STANDARD EN 27842:1991 NORME EUROPÉENNE October 1991 EUROPÄISCHE NORM UDC 621.646.9.057:621.186.1:620.1:532.57 Descriptors: Industrial valves, traps: drainage, water vapour, steam, tests, flow measurements English version Automatic steam traps — Determination of discharge capacity — Test methods (ISO 7842:1988) Purgeurs automatiques de vapeur d’eau — Détermination du débit — Méthodes d’essai (ISO 7842:1988) Kondensatableiter — Bestimmung des Durchflusses — Prüfverfahren (ISO 7842:1988) 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 Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © CEN 1991 Copyright reserved to all CEN members Ref No EN 27842:1991 E EN 27842:1991 Foreword On the proposal of the Technical Committee CEN/TC 69 “Industrial Valves” CEN BT decided by resolution C67/1990 to submit the International Standard ISO 7842:1988: Automatic steam traps — Determination of capacity — Test methods to Formal Vote This European Standard was adopted by CEN on August 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 Endorsement The text of the International Standard ISO 7482:1988 was approved by CEN as a European Standard without any modifications Contents Foreword Scope and field of application References Test arrangements Test method A Test method B Reporting of results — Test method A or B Bibliography Figure — Test arrangement for test method A Figure — Test arrangement for test method B — Continuous and intermittent flow Figure — Maximum submergence on steam trap versus test pressure Page 3 3 13 13 10 © BSI 11-1999 EN 27842:1991 Scope and field of application This International Standard specifies two test methods to determine the discharge capacity of automatic steam traps to ISO 6552 References ISO 651, Solid-stem calorimeter thermometers ISO 652, Enclosed-scale calorimeter thermometers ISO 653, Long solid-stem thermometers for precision use ISO 654, Short solid-stem thermometers for precision use ISO 4185, Measurement of liquid flow in closed conduits — Weighing method ISO 5167, Measurement of fluid flow by means of orifice plates, nozzles and Venturi tubes inserted in circular cross-section conduits running full ISO 5168, Measurement of fluid flow — Estimation of uncertainty of a flow-rate measurement ISO 6552, Automatic steam traps — Definition of technical terms Test arrangements The test arrangements for condensate capacity determination are shown in Figure and Figure All piping and equipment shall be insulated to a value of to reduce thermal losses to a minimum The instruments used for the measurements shall comply with International Standards, if such standards exist, e.g — ISO 651, ISO 652, ISO 653 and ISO 654 for temperature measurements; — ISO 4185, ISO 5167 and ISO 5168 for flow measurements The condensate removal device shall not be modified in any way from its commercial form Test method A © BSI 11-1999 EN 27842:1991 © BSI 11-1999 NOTE The diameter of the pipework from the accumulator to the condensate removal device shall be the same as, or greater than, the diameter of the pipework to the inlet connection on the device NOTE The distance L1 shall not exceed 10 internal pipe diameters NOTE The distance L2 shall be not less than 10 or more than 20 internal pipe diameters NOTE The distance Z shall be measured vertically from the centre of the inlet connection of the condensate removal device Figure — Test arrangement for test method A EN 27842:1991 4.1 Procedure NOTE Test method A is applicable only to continuous discharge measurement Start with all valves closed 4.1.1 Warm up the system by gradually opening valves 1, 2, 3, and 4.1.2 Adjust valves 1, and with valve wide open and valve closed to bring the system into equilibrium Equilibrium is defined as a steady water level in the accumulator with the vent valve partially open and a difference of °C or less showing on the temperature differential indicator 4.1.3 Observe and record the following data as appropriate depending on the method of condensate determination: — p1 = steam supply pressure, in bars1); — p2 = accumulator steam pressure, in bars; — p3 = trap inlet pressure, in bars; — p4 = trap outlet pressure, in bars; — Ú1 = steam supply temperature, in degrees Celsius; — Ú2 = water supply temperature, in degrees Celsius; — %Ú = temperature differential (subcooling) between steam in the accumulator and fluid entering the trap, in degrees Celsius; — X = steam supply quality, in per cent; — Z = accumulator water level, in metres; — %t = time interval, in hours, minutes or seconds; — qm1 = water supply flow-rate, in kilograms per hour; — qm2 = steam supply flow-rate, in kilograms per hour; — mc1 = mass of condensate and tank at start, in kilograms; — mc2 = mass of condensate and tank at end, in kilograms It is emphasized that Figure shows two alternative test arrangements for condensate measurement and that the choice is left to the test laboratory 4.1.4 Record the data specified in 4.1.3 at intervals for a minimum total of five sets of observations 4.1.5 During the test period observations as appropriate shall not exceed the following limits: a) the difference between the maximum and minimum tank level shall not exceed 50 mm; b) the maximum value of the tank level shall not exceed 450 mm at any time during the test; c) the maximum temperature differential (%Ú) shall not exceed °C during the test; d) no individual trap inlet pressure (p3) observation shall vary by more than % of the average of all observations; e) the calculated vent steam flow-rate (qm6) shall not exceed a maximum value equal to an exit velocity of 0,31 m/s in the tank 4.1.6 Repeat the operations specified in 4.1.1 to 4.1.5 as necessary to produce three sets of observations which result in three calculated capacity ratings, none of which varies from the average by more than 10 % 1) bar = 105 Pa © BSI 11-1999 EN 27842:1991 4.2 Flow calculations or where qmf is the discharge flow, in kilograms per hour; qm1 is the water flow, in kilograms per hour; qm3 is the steam flow to heat water supply (qm1), in kilograms per hour; qm4 is the flash steam flow in the accumulator, in kilograms per hour; qm8 is the accumulator storage rate, in kilograms per hour; mc1 and mc2 are as given in 4.1.3; h1 is the specific enthalpy of the supply water, in kilojoules per kilogram; h2 is the specific enthalpy of the supply steam, in kilojoules per kilogram; h3 is the specific enthalpy of saturated water at the supply pressure, in kilojoules per kilogram; h4 is the specific enthalpy of saturated steam in the accumulator, in kilojoules per kilogram; h5 is the specific enthalpy of saturated water in the accumulator, in kilojoules per kilogram; v1 is the specific volume of saturated steam in the accumulator, in cubic metres per kilogram; v2 is the specific volume of saturated water in the accumulator, in cubic metres per kilogram; %t is time interval, in seconds; D is the inside diameter of the accumulator, in metres; Z1 is the initial accumulator tank level, in metres; Z2 is the final accumulator tank level, in metres © BSI 11-1999 EN 27842:1991 4.3 Data sheet © BSI 11-1999 EN 27842:1991 Test method B © BSI 11-1999 © BSI 11-1999 Figure — Test arrangement for test method B — Continuous and intermittent flow EN 27842:1991 NOTE The piping from the accumulator to the test device shall be of the same diameter as the inlet connection on the test device This inlet to the piping from the accumulator shall be well-rounded NOTE The distance between the sensors and the test device shall not exceed 20 internal pipe diameters NOTE The distance Z shall be measured vertically from the centre of the inlet pipe connection of the test device and shall not exceed the distance shown in Figure NOTE The diagram indicates the use of a steam injector for heating the water in the accumulator It could equally be achieved by the use of a steam circulating coil inside the accumulator or any other means EN 27842:1991 5.1 Procedure Start with all valves closed 5.1.1 Open valves and and fill the accumulator tank to the desired level Close valve 5.1.2 Open valve and heat the water in the accumulator tank to the desired temperature Throttle valve as required to obtain water temperatures above 100 °C Leave valve open slightly while venting steam to purge air from the space above the water Close valves and and open valve 5.1.3 Open valves and to heat the test pipe and condensate removal device Monitor and adjust the system to produce the desired pressure at the test condensate removal device 5.1.4 When thermal equilibrium is reached, begin the test A circulation device may be necessary to ensure uniform temperature within the tank Do not take data until the tank level complies with that shown in Figure 5.1.5 Observe and record as appropriate the following data: a) elapsed time, in hours, minutes or seconds; b) ambient temperature Úa, in degrees Celsius; c) barometric pressure pa, in bars; d) steam pressure and temperature ps and Ús, in bars and degrees Celsius; e) initial and final values of the following: 1) temperature differential Ús – Úc, in degrees Celsius, 2) inlet pressure p1, in bars; 3) back pressure, p2, in bars; f) one of the following: 1) accumulator tank levels Z1 and Z2, in metres, 2) mass of condensate plus weight of tank at start and finish mc, in kilograms 5.1.6 Repeat the operations specified in 5.1.1 to 5.1.5 as necessary to produce three sets of observations which result in three calculated capacity ratings, none of which varies from the average by more than 10 % Figure — Maximum submergence on steam trap versus test pressure 10 © BSI 11-1999 EN 27842:1991 5.2 Flow calculations where qmf is the discharge flow, in kilograms per hour; D is the inside diameter of the accumulator, in metres; %t is the time interval, in seconds; vf is the specific volume of water in the accumulator, in cubic metres per kilogram; or where mc1 is the mass of condensate plus weigh tank at start, in kilograms; mc2 is the mass of condensate plus weigh tank at end, in kilograms 5.3 Data sheet © BSI 11-1999 11 EN 27842:1991 12 © BSI 11-1999 EN 27842:1991 Reporting of results — Test method A or B Test results may be reported only if the following additional data are reported: a) trap inlet pressure; b) trap outlet pressure; c) subcooling, %Ú A minimum of five tests shall be used to plot any graph The extrapolation of any graph outside of the pressure range covered by the tests shall be clearly marked and the maximum subcooling (%Úmax) and minimum outlet pressure of the tests shall be noted on the graph Bibliography ISO 6704, Automatic steam traps — Classification ISO 6948, Automatic steam traps — Production and performance characteristic tests © BSI 11-1999 13 BS EN 27842:1991 National appendix NA (informative) The United Kingdom participation in the preparation of this European Standard was entrusted by the Piping Systems Components Standards Policy Committee (PSE/-) to Technical Committee PSE/7, upon which the following bodies were represented: Amalgamated Engineering Union Association of Bronze and Brass Founders Association of Building Component Manufacturers British Chemical Engineering Contractors’ Association British Foundry Association British Gas plc British Maritime Technology British Plumbing Fittings Manufacturers’ Association British Valve and Actuator Manufacturers’ Association Chartered Institution of Building Services Engineers Copper Development Association Department of the Environment (Property Services Agency) Electricity Industry in United Kingdom Energy Industries Council Engineering Equipment and Materials Users’ Association Fire Extinguishing Trades Association GAMBICA (BEAMA Ltd.) Health and Safety Executive Institute of British Foundrymen Institution of Chemical Engineers Institution of Mechanical Engineers Institution of Water and Environmental Management Liquefied Petroleum Gas Industry Technical Association (UK) Pipeline Industries Guild Society of British Gas Industries Society of British Water Industries Water Companies Association Water Services Association of England and Wales West Midlands CBI 14 © BSI 11-1999 BS EN 27842:1991 National appendix NB (informative) The British Standards corresponding to the International Standards referred to in the text are as follows: International Standard British Standard ISO 653:1980 ISO 654:1980 BS 5074:1974 Specification for short and long solid-stem thermometers for precision use (Technically equivalent) ü ý þ ISO 4185:1980 BS 6199 Measurement of liquid flow in closed conduits using weighing and volumetric methods Part 1:1981 Weighing method (Identical) ISO 5167:1980 BS 1042 Measurement of fluid flow in closed conduits Section 1.1:1981 Specification for square-edged orifice plates, nozzles and venturi tubes inserted in circular cross section conduits running full (Technically equivalent) ISO 5168:1978 BS 5844:1980 Methods of measurement of fluid flow: estimation of uncertainty of a flow-rate measurement (Identical) ISO 6552:1980 BS 6023:1981 Glossary of technical terms for automatic steam traps (Identical) © BSI 11-1999 BS EN 27842:1991 ISO 7842:1988 BSI — British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the international level It is incorporated by Royal Charter Revisions British Standards are updated by amendment or revision Users of British Standards should make sure that they possess the latest amendments or editions It is the constant aim of BSI to improve the quality of our products and services We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover Tel: 020 8996 9000 Fax: 020 8996 7400 BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services Tel: 020 8996 9001 Fax: 020 8996 7001 In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service Various BSI electronic information services are also available which give details on all its products and services Contact the Information Centre Tel: 020 8996 7111 Fax: 020 8996 7048 Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards For details of these and other benefits contact Membership Administration Tel: 020 8996 7002 Fax: 020 8996 7001 Copyright Copyright subsists in all BSI publications BSI also holds the copyright, in the UK, of the publications of the international standardization bodies Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means – electronic, photocopying, recording or otherwise – without prior written permission from BSI This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained BSI 389 Chiswick High Road London W4 4AL If permission is granted, the terms may include royalty payments or a licensing agreement Details and advice can be obtained from the Copyright Manager Tel: 020 8996 7070