00257468 PDF BRITISH STANDARD BS EN 26704 1991 ISO 6704 1982 Classification of Automatic steam traps The European Standard EN 26704 1991 has the status of a British Standard BS EN 26704 1991 This Brit[.]
BRITISH STANDARD Classification of Automatic steam traps The European Standard EN 26704:1991 has the status of a British Standard BS EN 26704:1991 ISO 6704:1982 BS EN 26704:1991 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 Austria Belgium Denmark Finland France Germany Greece Iceland Ireland Italy Luxembourg Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom This British Standard was published under the authority of the Standards Board and comes into effect on 29 November 1991 © BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference PSE/7 Draft for comment 80/71920 DC ISBN 580 20219 Oesterreichisches Normungsinstitut Institut belge de normalisation Dansk Standardiseringsraad Suomen Standardisoimisliito, r.y Association franỗaise de normalisation Deutsches Institut fỹr Normung e.V Hellenic Organization for Standardization Technological Institute of Iceland National Standards Authority of Ireland Ente Nazionale Italiano di Unificazione Inspection du Travail et des Mines Nederlands Normalisatie-instituut Norges Standardiseringsforbund Instituto Portuguès da Qualidade Asociación Espola de Normalización y Certificación Standardiseringskommissionen i Sverige Association suisse de normalisation British Standards Institution Amendments issued since publication Amd No Date Comments BS EN 26704:1991 Contents Cooperating organizations National foreword Foreword Text of EN 26704 National appendix NA (informative) National appendix NB (informative) © BSI 09-1999 Page Inside front cover ii Inside back cover Inside back cover i BS EN 26704:1991 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 26704:1991 “Automatic steam traps — Classification” published by the European Committee for Standardization (CEN) It supersedes BS 6022:1983 which is withdrawn EN 26704:1991 is identical with ISO 6704:1982 published by the International Organization for Standardization (ISO) A British Standard does not purport to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 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 ii © BSI 09-1999 EUROPEAN STANDARD EN 26704:1991 NORME EUROPÉENNE October 1991 EUROPÄISCHE NORM UDC 621.646.9.057.6:621.186.6:6:001.4 Descriptors: Valves and fittings, traps: drainage, water vapour, steam, automatic equipment, classification English version Automatic steam traps — Classification (ISO 6704:1980) Purgeurs automatiques de vapeur d’eau — Classification (ISO 6704:1980) Kondensatableiter — Klassifikation (ISO 6704:1980) 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 26704:1991 E EN 26704:1991 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 6704:1952, Automatic steam traps — Classification to Formal Vote This European Standard EN 26704 was approved by CEN on 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 Foreword Scope and field of application References Definition Classification Page 3 3 © BSI 09-1999 EN 26704:1991 Scope and field of application Classification The purpose of this International Standard is to establish a simple classification of the main types of automatic steam traps according to the mode of actuation of their obturation device and disregarding their details of conception and construction The types of traps defined hereunder are classified according to their mode of actuation; other traps, combining these different types (or of a new design) may be developed, but these traps shall not be regarded as a characteristic type of automatic steam traps in the sense of this International Standard If one considers the mode of actuation of the obturation device, three categories of automatic steam traps can be distinguished: — mechanical traps, actuated by the level of condensate (4.1); — thermostatic traps, actuated by the temperature of condensate (4.2); — thermodynamic traps, actuated by fluid dynamics (4.3) References ISO 6552, Automatic steam traps — Terminology ISO 6553, Automatic steam traps — Marking ISO 6554, Flanged automatic steam traps — Face-to-face dimensions Definition For this International Standard, the following definition applies: 3.1 automatic steam trap self-contained valve which automatically drains the condensate from a steam-containing enclosure whilst remaining tight to live steam or, if necessary, allowing steam to flow at a predetermined rate © BSI 09-1999 EN 26704:1991 Sketch (diagrammatic) Operation 4.1 Mechanical traps (float traps) (actuated by the level of condensate) 4.1.1 Steam trap with closed float The opening or closing movements of the obturator are caused by the variations of the level of condensate in the trap shell 4.1.2 Steam trap with open top float The opening or closing movements of the obturator are caused by the variations of the level of condensate in the float 4.1.3 Steam trap with open inverted float The opening or closing movements of the obturator are caused by the variations of the level of condensate in the float © BSI 09-1999 EN 26704:1991 Sketch (diagrammatic) Operation 4.2 Thermostatic traps (actuated by the temperature of condensate) 4.2.1 Vapour pressure trap The opening or closing movements of the obturator are actuated by imbalances created between the pressure of condensate in the trap and the vapour pressure of the volatile liquid contained in a deformable element 4.2.2 Bimetallic or thermoelastic trap The temperature changes of the incoming condensate cause the deformation of the bimetallic or thermoelastic element, and consequently the opening and closing movements of the obturator 4.2.3 Liquid or solid expansion trap The opening or closing movements of the obturator are caused by the temperature variations of the condensate acting on an element with a high thermal expansion coefficient © BSI 09-1999 EN 26704:1991 Sketch (diagrammatic) Operation 4.3 Thermodynamic traps (actuated by fluid dynamics) 4.3.1 Obturator trap The successive differences of pressure between the inlet and the pressure chamber cause the opening or closing movements of the obturator 4.3.2 Impulse trap The successive differences of pressure between the inlet and the pressure chamber cause the opening or closing movements of the obturator (piston valve) 4.3.3 Labyrinth or orifice trap Fluids pass freely through the orifice Condensate may eliminate or reduce the flow of steam or non-condensables © BSI 09-1999 BS EN 26704:1991 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 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 6552:1980 BS 6023:1981 Glossary of technical terms for automatic steam traps (Identical) BS EN 26553:1991 Specification for marking of automatic steam traps (Identical) BS EN 26554:1991 Specification for face-to-face dimensions for flanged automatic steam traps (Identical) ISO 6553:1980 ISO 6554:1980 © BSI 09-1999 BS EN 26704:1991 ISO 6704:1982 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