ISO INTERNATIONAL STANDARD 14520-1 Fourth edition 2023-02 Gaseous fire-extinguishing systems Physical properties and system design - Part 1: General requirements Systemes d'extinction d'incendie utilisant des agents gazeux - Proprietés physiques et conception des systemes Partie 1: Exigences générales Reference number ISO 14520-1:2023(E) osi @IS02023 IS0 14520-1:2023(E) COPYRIGHT PROTECTED DOCUMENT @ISO2023 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on or ISo's member body in the country of the requester. ISO copyright office CP 401 · Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Email: [email protected] Website: www.iso.org Published in Switzerland i @ IS0 2023 - All rights reserved IS0 14520-1:2023(E) Contents Page Foreword vi Introduction. .vii 1 Scope. 2 Normative references 3 Terms and definitions. 4 Use and limitations. 4.1 General .6 4.2 Extinguishants. ..6 4.2.1 General. ..6 4.2.2 Environmental properties 4.3 Electrostatic discharge 7 4.4 Compatibility with other extinguishants 4.5 Temperature limitations.. 7 5 Safety .8 5.1 Hazard to personnel ..8 5.2 Safety precautions... 5.2.1 General ..8 5.2.2 For normally occupied areas .9 5.2.3 For normally unoccupied areas .10 5.2.4 For unoccupiable areas. 5.3 Occupiable areas .10 5.4 Electrical hazards. ..11 5.5 Electrical earthing .12 5.6 Electrostatic discharge .12 6 System design. .12 6.1 General .12 6.2 Extinguishant supply .12 6.2.1 Quantity ..12 6.2.2 Quality .12 6.2.3 Container arrangement .12 6.2.4 Storage containers. .13 6.3 Distribution 14 6.3.1 General 14 6.3.2 Piping. ..15 6.3.3 Fittings 15 6.3.4 Pipe and valve supports ..15 6.3.5 Valves 16 6.3.6 Nozzles 16 6.3.7 Pressure reducing orifice assembly .. 17 6.4 Detection, actuation and control systems 17 6.4.1 General 6.4.2 Automatic detection. 17 6.4.3 Operating devices. ..18 6.4.4 Control equipment. ..18 6.4.5 Operating alarms and indicators. 6.4.6 Hold switches 19 7 Extinguishant system design ..19 7.1 General 19 7.2 Specifications, plans and approvals .19 7.2.1 Specifications. .. 19 7.2.2 Working documents. .. 19 7.3 System flow calculations. .20 @IS02023-All rightsreserved iii IS0 14520-1:2023(E) 7.3.1 General 20 7.3.2 A balanced and unbalanced system .20 7.3.3 Friction losses.. 21 7.3.4 Pressure drop. 21 7.3.5 Elevation changes 22 7.3.6 Valves and fittings. 22 7.3.7 Piping length. 22 7.3.8 Drawings 22 7.3.9 Liquefied gases Specific requirements 22 7.4 Enclosures.. 22 7.5 Effects of noise. 22 7.6 Extinguishant concentration requirements 23 7.6.1 Flame extinguishment. 23 7.6.2 Inerting. 24 7.7 Total flooding quantity 25 7.7.1 General 25 7.7.2 Liquefied gases. 25 7.7.3 Non-liquefied gas 25 7.8 Altitude adjustment. 26 7.9 Duration of protection 26 7.10 System performance. 27 7.10.1 Dischargetime .27 7.10.2 Extended discharge 27 8 Commissioning and acceptance 27 8.1 General. 27 8.2 Tests. 27 8.2.1 General 27 8.2.2 Enclosure check. 27 8.2.3 Review of mechanical components 28 8.2.4 Review of enclosure integrity. 29 8.2.5 Review of electrical components. 29 8.2.6 Preliminary functional tests. 30 8.2.7 System functional operational test. 30 8.2.8 Remote monitoring operations (if applicable) 31 8.2.9 Control panel primary power source. 31 8.2.10 Completion of functional tests 31 8.3 Completion certificate and documentation 31 9 Inspection, maintenance, testing and training .31 9.1 General 31 9.2 Inspection. 32 9.2.1 General 32 9.2.2 Container 32 9.2.3 Hose. .32 9.2.4 Enclosures 32 9.3 Maintenance. 33 9.3.1 General 33 9.3.2 User's programme of inspection 33 9.3.3 Service schedule 33 9.4 Training 33 Annex A (normative) Working documents .34 Annex B (normative) Determination of flame-extinguishing concentration of gaseous extinguishants by the cup burner method .36 Annex C (normative) Fire