ISO INTERNATIONAL STANDARD 4126-9 First edition 2008-04-15 Safety devices for protection against excessive pressure - Part 9: Application and installation of safety devices excluding stand-alone bursting disc safety devices Dispositifs de sécurite pourprotection contre les pressions excessives- Partie 9: Application et installation des dispositifs de sécurite autres que les dispositifs a disque de rupture installés seuls Reference number ISO 4126-9:2008(E) @ ISO 2008 IHS under ted without license from IHS Not for Resale ISO 4126-9:2008(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's 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 performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's 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 inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT @ ISO2008 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, IsO's 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 copyright@iso.org Web www.iso.org Published in Switzerland @ IS0 2008 - All rights reserved py IHS unde I without license from IHS Not for Resale ISO 4126-9:2008(E) Contents Page Foreword. Introduction 1 Scope 2 Normative references 3 Terms and definitions 4 Risk consideration. 5 Pressure limitation 5.1 General. 5.2 Setting of safety devices... 6 Inlet line 7 Outlet line 8 Installation. 8.1 8 8.2 Installation of safety valves or the main valve of a CSPRS or a POSV.... 8 8.3 Installation of safety valves and bursting disc safety devices in series or parallel... 8.4 Isolation of safety devices ........ 10 9 Lifting device. 11 Annex A (informative) Safety device applications 12 Annex B (informative) Sizing of multiple safety devices... .15 Annex C (informative) Sizing of inlet lines. 17 Annex D (informative) Calculation of built-up back pressure... 22 AnnexE(informative)Calculationofreactionforces. 29 Annex F (informative) Calculation of noise level.. 30 Bibliography ... 31 CopyrightInternational Oganzaonsandardizaloghtsreserved ii nse from IHS Not for Resale