BS-EN-ISO-10156-2-2005.pdf

BRITISH STANDARD BS EN ISO 10156-2:2005 Gas cylinders Gases and gas mixtures Part 2: Determination of oxidizing ability of toxic and corrosive gases and gas mixtures The European Standard EN ISO 10156-2:2005 has the status of a British Standard ICS 23.020.30; 71.100.20 ? Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 10156-2:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2006 © BSI 2006 ISBN 0 580 48912 4 National foreword This British Standard is the official English language version of EN ISO 10156-2:2005, including Corrigendum June 2006. It is identical with ISO 10156-2:2005. The UK participation in its preparation was entrusted by Technical Committee PVE/3, Gas containers, to Subcommittee PVE/3/7, Gas cylinder operations, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. 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 does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO title page, pages ii and iii, a blank page, pages 1 to 7 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN ISO 10156-2 August 2005 ICS 23.020.30; 71.100.20 English Version Gas cylinders Gases and gas mixtures Part 2: Determination of oxidizing ability of toxic and corrosive gases and gas mixtures (ISO 10156-2:2005) Bouteilles à gaz Gaz et mélanges de gaz - Partie 2: Détermination du pouvoir oxydant des gaz et mélanges de gaz toxiques et corrosifs (ISO 10156-2:2005) Gasflaschen - Gase und Gasgemische Teil 2: Bestimmung des Oxidationsverhaltens von giftigen und korrosiven Gasen und Gasgemischen (ISO 10156-2:2005) This European Standard was approved by CEN on 31 July 2005. 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels © 2005 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 10156-2:2005: E Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Foreword This document (EN ISO 10156-2:2005) has been prepared by Technical Committee ISO/TC 58 “Gas cylinders“ in collaboration with Technical Committee CEN/TC 23 “Transportable gas cylinders“, the secretariat of which is held by BSI. 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 2006, and conflicting national standards shall be withdrawn at the latest by February 2006. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 10156-2:2005 has been approved by CEN as EN ISO 10156-2:2005 without any modifications. EN ISO 10156-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Reference number ISO 10156-2:2005(E) INTERNATIONAL STANDARD ISO 10156-2 First edition 2005-08-01 Gas cylinders Gases and gas mixtures Part 2: Determination of oxidizing ability of toxic and corrosive gases and gas mixtures Bouteilles à gaz Gaz et mélanges de gaz Partie 2: Détermination du pouvoir oxydant des gaz et mélanges de gaz toxiques et corrosifs EN ISO 10156-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iii 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 10156-2 was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee SC 2, Cylinder fittings. This first edition of ISO 10156-2, together with the future ISO 10156-1 (under preparation), will cancel and replace ISO 10156:1996, which has been technically revised. ISO 10156 consists of the following parts, under the general title Gas cylinders Gases and gas mixtures: Part 2: Determination of oxidizing ability of toxic and corrosive gases and gas mixtures EN ISO 10156-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 1 Gas cylinders Gases and gas mixtures Part 2: Determination of oxidizing ability of toxic and corrosive gases and gas mixtures WARNING 1 There may be a risk of explosion when carrying out the test specified in this part of ISO 10156. Special care is to be taken when dealing with toxic and corrosive gases. Personnel shall be made aware of the potential hazards and shall take the necessary precautions. The test apparatus should be installed in a laboratory fume cupboard. WARNING 2 Fuel gas and oxidants to be tested shall not be mixed together under pressure in gas cylinders, except by competent persons to a well proven procedure. This part of ISO 10156 does not attempt to clarify which oxidizing gas mixtures can be manufactured safely and successfully; this is the responsibility of the mixture manufacturer using established practices and procedures to ensure the safety of personnel, equipment, and surroundings. 1 Scope This part of ISO 10156 specifies a test and a calculation method to be used for determining whether or not a gas (or a gas mixture) is more oxidizing than air. This part of ISO 10156 only applies to toxic and corrosive gases and gas mixtures. 2 Test method 2.1 Principle The gas or gas mixture to be evaluated (X) is mixed at a fixed ratio with nitrogen (N) to form a mixture (XN). That fixed ratio shall be the same as in the limiting mixture (NA) of nitrogen and air (A), which just does not support combustion of the reference combustible “ethane” (C) (see Figure 1). By using the apparatus described in 2.2, the mixture XN is then mixed with increasing amounts of the reference combustible (C) to form test mixtures (XNC). By applying the procedure and criterion to determine flammability, it is observed if these test mixtures are flammable. If any mixture of XN and C is flammable, the gas to be evaluated (X) is considered to be more oxidizing than air. If flammability is not observed in a range of combustible contents up to a maximum value (cmax), the gas to be evaluated is considered to be no more oxidizing than air. EN ISO 10156-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 2 Key X air in mol % Y ethane in mol % Z nitrogen in mol % 1 explosion range 2 line of constant ratio oxidizer/nitrogen 3 limiting oxidizer fraction, LOF = 43,4 mol % air Figure 1 Determination of limiting oxidizer fraction of air in nitrogen, which does not support the combustion of ethane 2.2 Apparatus and materials 2.2.1 Description The apparatus (see Figure 2) includes a closed test vessel with stirrer; an ignition system; two pressure measuring systems; a system for checking the test gas composition. 2.2.2 Test vessel The test vessel shall be made of stainless steel and designed to withstand a maximum overpressure of at least 30 bar (3 MPa). The volume shall be at least 0,005 m3. It can be either cylindrical or spherical. If a cylindrical vessel is used, the length-to-diameter ratio shall be 1. The vessel shall incorporate a stirrer and sufficient ports to enable filling, evacuation and purging. The vessel shall be equipped with a suitable temperature measuring device. EN ISO 10156-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 3 2.2.3 Ignition system A fusing wire igniter shall be used. This ignition device generates an electric arc by passing an electric current along a straight length of a NiCr-wire connecting two metal rods. The rods (diameter at least 3 mm) shall be parallel to one another at a separation distance of (5 ± 1) mm. The diameter of wire shall be between 0,05 mm and 0,2 mm. The electrical power for melting this wire and generating the arc is supplied by an a.c. isolating transformer (power 0,7 kVA to 3,5 kVA; secondary voltage 230 V). The secondary winding of the transformer shall be switched to the rods by an electronic device allowing adjustment of the ignition energy between 10 J and 20 J. This can be achieved by phase-angle control of secondary voltage by thyristor switching elements. The fusing wire shall be positioned in the centre of the test vessel. 2.2.4 Pressure measuring system The pressure measuring system for the explosion pressure consists of a pressure transducer, an amplifier and a data recording system. The pressure transducer and amplifier shall have a time resolution of at least 1 ms. The transducer shall be pressure resistant to at least a pressure of 30 bar (3 MPa) with a measuring range of 10 bar. The pressure indication system for preparing the test mixtures according to the partial pressure method (pressure transducers or manometers) shall have a measuring range of 2 bar (200 kPa) maximum. Both pressure measuring systems shall have an accuracy of 0,5 % full scale or better. 2.2.5 System for checking the test gas composition The mixture XN or XNC shall be analysed using a gas chromatograph or another suitable type of analyser. EN ISO 10156-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 4 Key 1 supply of pressurized oxidizer gas 2 supply of pressurized nitrogen gas 3 supply of pressurized ethane gas 4 test vessel made of stainless steel with magnetic stirrer 5 recording unit for pressure rise inside the ignition vessel 6 fusing wire igniter and electronic control unit 7 pressure indication for preparing test mixtures 8 vacuum pump a Waste gas. Figure 2 Example of apparatus for determination of oxidizing ability of toxic and corrosive gases EN ISO 10156-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 08:41:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 5 2.2.6 Materials Ethane (purity 99,5 %) shall be used as reference combustible (C). Ethane was selected for reference fuel because it has carbonhydrogen bonds and also a carboncarbon bond as most of the combustible materials do. Flammability ranges of ethane with many oxidizing gases were already known. The mixture (XN) shall consist of (43 ± 1) mol % gas to be evaluated and (57 ± 1) mol % nitrogen of a purity 99,995 %. XN can be prepared directly in the test vessel according to the partial pressure of each component. It is also admissible to produce a pressurized mixture (XN) in an evacuated gas cylinder with the aid of an additional metering device and to use this premixed gas for the subsequent procedure. The mixture (XN), or one of the mixtures (XNC) when this mixture is directly made in the autoclave, shall be analysed. The moisture content of gases shall be less than 10 µl/l. If for any reason (e.g. hygroscopic gases or unknown substances) this cannot be achieved, this fact shall be indicated in the report. 2.3 Procedure The tests shall be carried out at room temperature and atmospheric pressure.