IEC IEC63341-2 Edition 1.02025-11 INTERNATIONAL STANDARD Railway applications -Hydrogen and fuel cell systems for rolling stock Part 2: Hydrogen fuel system IEC 63341-2:2025-11(en) ICS 45.060.01; 27.070 ISBN 978-2-8327-0735-7 THIS PUBLICATIONIS COPYRIGHTPROTECTED Copyright@2025IEC,Geneva,Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or IEc or IEC's member National Committee in the country of the requester. If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local IEC memberNational Committee for further information. IEC Secretariat Tel.: +41 22 919 02 11 3, rue de Varembé [email protected] CH-1211 Geneva 20 www.iec.ch Switzerland About the IEC International Standards for all electrical, electronic and related technologies. About IECpublications The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the latest edition, a corrigendum or an amendment might have been published. IECpublications search- IEcProducts&Services Portal-products.iec.ch webstore.iec.ch/advsearchform Discover our powerful search engine and read freely all the The advanced search enables to find IEC publications by a publications previews, graphical symbols and the glossary. variety. of criteria (reference number, text, technical With a subscription you wili always have access to up to date committee, ...). It also gives information on projects, content tailored to your needs. replaced and withdrawn publications. Electropedia -www.electropedia.org IEC JustPublished-webstore.iec.ch/justpublished The world's leading online dictionary on electrotechnology, Stay up to date on all new IEC publications. Just Published containing more than 22 500 terminological entries in English details all new publications released. Available online and and French, with equivalent terms in 25 additional languages. once a month by email. Also known as the international Electrotechnical Vocabulary (IEV) online. IEC Customer Service Centre -webstore.iec.ch/csc If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: [email protected]. Warning! Make sure that you obtained this publication from an authorized distributor. IEC63341-2:2025@IEC2025 CONTENTS FOREWORD .6 INTRODUCTION. .8 1 Scope.. 2 Normative references .. .9 3 Terms, definitions and abbreviated terms 10 3.1 Terms and definitions.. 3.2 Abbreviated terms... ..18 4 Hydrogen fuel system description. .19 4.1 Overview.... 4.2 ..20 4.3 Hydrogen handling system (HHS) ..20 4.4 On-boardfuellinginterface. .21 4.5 Fuel,purge and discharge lines .21 4.6 Monitoring and control system (Mcs) .21 4.7 Safety monitoring devices (optional) .22 5 Environmental requirements. .22 5.1 General.. ..22 5.2 Ambient air temperature.... ..22 5.3 Humidity .... ..22 5.4 Altitude... 5.5 Air movement, rain, snow,hail and solar radiation 5.6 Atmosphere corrosivity and pollution degree 5.7 Other constraints from the environment ...23 ...23 9 Interface requirements.. 6.1 General.... 6.2 Fluidic hydrogen interfaces . 6.2.1 Hydrogen supply from HHS toFCPS ...23 6.2.2 Fluidic interface with fuelling station ... ..24 6.2.3 Purging fluidic interfaces .. ..24 6.2.4 Discharge of hydrogen to the atmosphere in case of fire.. ..25 6.2.5 Discharge of hydrogen to the atmosphere in case of overpressure . ..26 6.3 Electrical hardwire interfaces ... ..26 6.4 Communication interfaces. 6.4.1 Interface with other on-board controllers. 6.4.2 Interface with fuelling station (optional). 6.4.3 Interface with maintenance tools (optional). ..26 7 Performance requirements of the HFS. ..27 8 Design requirements for hydrogen fuel system . 8.1 General.. ..27 8.2 Hydrogen quality... .27 8.3 Pressure ranges. 8.3.1 High-pressure section.... 8.3.2 Medium-pressure section. ..30 8.4