BS ISO 25760-2009 气瓶.从气瓶上安全卸除阀门的操作规程.pdf

BS ISO 257602009 ICS 23.020.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Gas cylinders Operational procedures for the safe removal of valves from gas cylinders This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2009 BSI 2009 ISBN 978 0 580 57712 3 Amendments/corrigenda issued since publication DateComments BS ISO 257602009 National foreword This British Standard is the UK implementation of ISO 257602009. The UK participation in its preparation was entrusted to Technical Committee PVE/3/7, Gas cylinder receptacle operations. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. 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 ISO 257602009 Reference number ISO 257602009E ISO 2009 INTERNATIONAL STANDARD ISO 25760 First edition 2009-06-15 Gas cylinders Operational procedures for the safe removal of valves from gas cylinders Bouteilles gaz Modes opratoires de dpose en toute scurit des robinets de bouteilles gaz w w w . b z f x w . c o m BS ISO 257602009 ISO 257602009E PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer pering the editing. In downloading this file, parties accept therein the respons bility of not infringing Adobes licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please in the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2009 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. 41 22 749 01 11 Fax 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 – All rights reserved 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 ISO 257602009 ISO 257602009E ISO 2009 – All rights reserved iii Contents Page Foreword............................................................................................................................................................ iv Introduction........................................................................................................................................................ v 1 Scope ..................................................................................................................................................... 1 2 Normative references........................................................................................................................... 1 3 Terms and definitions........................................................................................................................... 1 4 General requirements........................................................................................................................... 3 4.1 Application ............................................................................................................................................ 3 4.2 Hazards.................................................................................................................................................. 3 4.3 Operator safety and protection........................................................................................................... 3 4.4 Operator qualifications......................................................................................................................... 3 4.5 Operator errors ..................................................................................................................................... 4 4.6 Special valve designs........................................................................................................................... 5 5 s for inoperable valves............................................................................................................ 5 5.1 Summary of s........................................................................................................................... 5 5.2 Choice of .................................................................................................................................. 6 6 Procedures ............................................................................................................................................ 6 6.1 Procedures to identify and segregate cylinders with inoperable valves........................................ 6 6.2 Standard dving procedure for treating cylinders with operable valves................................... 7 6.3 Procedures for treating cylinders with inoperable valves................................................................ 8 7 Damaged valves and cylinders ........................................................................................................... 8 Annex A inative Reasons cylinder valves become inoperable ........................................................... 9 Annex B inative Examples of s for depressurization of gas cylinders with inoperable valves................................................................................................................................................... 11 Bibliography..................................................................................................................................................... 18 w w w . b z f x w . c o m BS ISO 257602009 ISO 257602009E iv ISO 2009 – All rights reserved Foreword ISO the International Organization for Standardization is a worldwide federation of national standards bodies ISO member bodies. The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission IEC on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 25760 was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee SC 4, Operational requirements for gas cylinders and is based on EIGA Document 129/05 Pressure receptacles with blocked or inoperable valves. EIGA has granted permission to reproduce excerpts from their document. 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 ISO 257602009 ISO 257602009E ISO 2009 – All rights reserved v Introduction Cylinders are dved for many purposes, such as periodic inspection and testing, cylinder cleaning, change of service, replacement of a damaged valve, installation of a new valve, preparation for filling or scrapping. Occasionally, gas cylinder valves can become blocked by corrosion or foreign material or become inoperable due to external or internal damage. It is an essential safety requirement that such valved cylinders be identified and treated with special care as soon as practicable. The operation of removing a valve should only be carried out if the cylinder is made safe with respect to residual gas and pressure. It is recommended that gas suppliers be prepared with both the proper equipment and trained operators for dealing with such valved cylinders. Practical techniques that have been tried and tested over many years within the gas industry are described. Valve removal activities can pose hazards to the life and physical safety of the operator, especially if the cylinder is under pressure. Valves should only be removed after ensuring there is no residual pressure in the cylinder. w w w . b z f x w . c o m BS ISO 257602009 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 ISO 257602009 INTERNATIONAL STANDARD ISO 257602009E ISO 2009 – All rights reserved 1 Gas cylinders Operational procedures for the safe removal of valves from gas cylinders 1 Scope This International Standard is intended for suppliers, operators in testing facilities, operators pering cylinder maintenance and any person authorized to remove valves from gas cylinders. It details procedures for the safe removal of valves from cylinders and includes techniques for the identification of inoperable valves. Only the risks due to gas and gas mixtures under pressure are addressed; other technical issues relating to the removal of a valve from a cylinder are not covered. Some specialized equipment and procedures are in use in parts of the gas industry to safely remove cylinder valves from low pressure gas cylinders while under pressure, e.g. liquefied petroleum gas LPG; these techniques are not included in this International Standard. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document including any amendments applies. ISO 11114-1, Transportable gas cylinders Compatibility of cylinder and valve materials with gas contents Part 1 Metallic materials ISO 11114-2, Transportable gas cylinders Compatibility of cylinder and valve materials with gas contents Part 2 Non-metallic materials 3 Terms and definitions For the purposes of this document, the following terms and definitions apply 3.1 gas cylinder pressure receptacle including individual cylinder, tube, pressure drum or manifold combination of these 3.2 valve device that allows gas to enter or exit a gas cylinder and retains the pressure in the cylinder when in the closed position NOTE This also includes the fittings of cylinders in bundles and battery vehicles. 3.3 inoperable valve valve that is blocked, broken or malfunctioning or that in any way prevents gas from entering or exiting the gas cylinder NOTE See Annex A. w w w . b z f x w . c o m BS ISO 257602009 ISO 257602009E 2 ISO 2009 – All rights reserved 3.4 operable valve device that allows gas to enter or exit a gas cylinder 3.5 residual pressure valve RPV type of valve that prevents the gas cylinder from being totally depressurized by holding back a specific amount of residual pressure NOTE 1 Requirements for this type of valve are specified in ISO 15996. NOTE 2 This valve type is very often associated with a non-return function. 3.6 valve with integrated pressure regulator VIPR device intended to be permanently fitted to a gas cylinder connection and comprising a shut-off valve system and pressure reduction system NOTE 1 Adapted from ISO 224352007, definition 3.3. NOTE 2 Requirements for this type of valve are specified in ISO 15996. 3.7 pressure relief device PRD device that is fitted to the cylinder or cylinder valve and designed to relieve gas pressure in the event of abnormal conditions resulting in the development of excessive pressure inside the cylinder or when the cylinder is subjected to high temperatures NOTE 1 This might be a pressure relief valve, a non-reclosing PRD or a non-reclosing PRD in combination with a pressure relief valve. NOTE 2 The expression “pressure relief” is synonymous with “safety relief”, as used in various applicable regulations, codes, standards or specifications. 3.8 quick connect valve clip-on valve valve that does not contain an operating device, such as a handwheel 3.9 low pressure gas cylinder gas cylinder with test pressures no higher than 60 bar1 3.10 compressed gas gas which, when packaged under pressure for transport, is entirely gaseous at all temperatures above − 50 C NOTE This category includes all gases with a critical temperature less than or equal to − 50 C. 1 1 bar 100 kPa exactly 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 ISO 257602009 ISO 257602009E ISO 2009 – All rights reserved 3 4 General requirements 4.1 Application This clause gives general ination to be considered. Clause 5 gives a choice of s for inoperable valves. Procedures to be followed are given in Clause 6. 4.2 Hazards Especially if the cylinder is under pressure, valve removal s pose certain hazards to the operator, such as ⎯ stored energy from residual pressure particularly important if the cylinder is not in a vertical position; ⎯ residual gas hazards, including ⎯ fire resulting from flammable gas ignitions NOTE Oxidizing gases in the presence of contamination can also cause severe ignition. ⎯ asphyxiation, ⎯ oxidation, ⎯ toxicity/corrosivity, ⎯ projection of pieces under pressure, ⎯ cold burns due to vaporization of liquefied gases; and ⎯ operating dving machinery and equipment, such as pinch points, rotation and powered machines. 4.3 Operator safety and protection When an operator is removing a blocked or inoperable valve, other individuals should be on site and able to respond in case of an emergency. A risk assessment shall be pered in order to avoid the exposure of the operator and other persons who could be affected by hazards. The minimum hazards to take into account for this risk analysis are listed in 4.2. After the r