ISO 14520-1:2023
(Main)Gaseous fire-extinguishing systems — Physical properties and system design — Part 1: General requirements
Gaseous fire-extinguishing systems — Physical properties and system design — Part 1: General requirements
This document specifies requirements and gives recommendations for the design, installation, testing, maintenance and safety of gaseous firefighting systems in buildings, plants or other structures, and the characteristics of the various extinguishants and types of fire for which they are a suitable extinguishing medium. It covers total flooding systems primarily related to buildings, plants and other specific applications, utilizing electrically non-conducting gaseous fire extinguishants that do not leave a residue after discharge and for which there are sufficient data currently available to enable validation of performance and safety characteristics by an appropriate independent authority. This document does not apply to explosion suppression. This document is not intended to indicate approval of the extinguishants listed therein by the appropriate authorities, as other extinguishants can be equally acceptable. CO2 is not included as it is covered by other International Standards. This document applies to the extinguishants listed in Table 1. It is essential that it be used in conjunction with the separate parts of the ISO 14520 series for specific extinguishants, as cited in Table 1.
Systèmes d'extinction d'incendie utilisant des agents gazeux — Propriétés physiques et conception des systèmes — Partie 1: Exigences générales
General Information
Relations
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 14520-1
Fourth edition
2023-02
Gaseous fire-extinguishing systems —
Physical properties and system
design —
Part 1:
General requirements
Systèmes d'extinction d'incendie utilisant des agents gazeux —
Propriétés physiques et conception des systèmes —
Partie 1: Exigences générales
Reference number
ISO 14520-1:2023(E)
© ISO 2023
---------------------- Page: 1 ----------------------
ISO 14520-1:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
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
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
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: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
© ISO 2023 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 14520-1:2023(E)
Contents Page
Foreword . vi
Introduction .viii
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 3
4 Use and limitations . 6
4.1 General . 6
4.2 Extinguishants. 6
4.2.1 General . 6
4.2.2 Environmental properties . 7
4.3 Electrostatic discharge . 7
4.4 Compatibility with other extinguishants . 7
4.5 Temperature limitations . 7
5 Safety . 8
5.1 Hazard to personnel . 8
5.2 Safety precautions . 8
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 . 10
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 . 17
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 . 19
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
iii
© ISO 2023 – All rights reserved
---------------------- Page: 3 ----------------------
ISO 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 Discharge time . 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 extinguishment/area coverage fire test procedure for engineered
and pre-engineered extinguishing units .42
Annex D (informative) Method of evaluating inerting concentration of a fire extinguishant .71
iv
© ISO 2023 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 14520-1:2023(E)
Annex E (normative) Door fan test for determining of minimum hold time .74
Annex F (informative) System performance verification .90
Annex G (normative) Safe personnel exposure guidelines .91
Annex H (informative) Flow calculation implementation method and flow calculation
verification and testing for approvals .99
Annex I (informative) Scaling factors for Class B fuels other than heptane . 103
Annex J (normative) Criteria for assessment of new extinguishants for inclusion in the ISO
14520 series . 104
Bibliography . 106
v
© ISO 2023 – All rights reserved
---------------------- Page: 5 ----------------------
ISO 14520-1:2023(E)
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 21, Equipment for fire protection and fire
fighting, Subcommittee SC 8, Gaseous media and firefighting systems using gas.
This fourth edition cancels and replaces the third edition (ISO 14520-1:2015), which has been
technically revised. It also cancels and replaces ISO/TR 23107:2021.
The main changes are as follows:
— the Scope has been extended to cover an additional agent, halocarbon blend 55;
— subclause 5.2.1 has been amended to require upper limit threshold concentrations to be established
for any impurity that could result in acute toxicity at concentrations below the cardiac sensitization
NOAEL of the agent. Subclause G.4.4 has also been added to provide further information on these
requirements;
— a new subclause (6.4.4.2) has been added requiring that in the event of an electrical actuator being
removed from a container valve or selector valve, an audible and visual alarm is to be provided at
the control panel;
— subclause 7.4.1 has been amended to draw attention to ISO 21805;
— a new subclause (7.5) has been added providing guidance regarding the effects of noise that can be
caused by the alarm devices or the discharge of the agent;
— subclause 7.6.1.3, (previously 7.5.1.3) has been amended to give several scenarios to explain the
recommended selection of regular and high hazard design concentrations;
— Annex I has been added to reflect the content of the withdrawn document ISO/TR 12854;
— Annex J has been added to reflect the content of ISO/TR 23107 (to be withdrawn).
A list of all parts in the ISO 14520 series can be found on the ISO website.
vi
© ISO 2023 – All rights reserved
---------------------- Page: 6 ----------------------
ISO 14520-1:2023(E)
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
vii
© ISO 2023 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 14520-1:2023(E)
Introduction
Firefighting systems covered in this document are designed to provide information on a supply of
gaseous extinguishing medium for the extinction of fire.
Several different methods of supplying extinguishant to, and applying it at, the required point of
discharge for fire extinction have been developed in recent years, and there is a need for dissemination
of information on established systems and methods. This document has been prepared to meet this
need.
The requirements of this document are made in the light of the best technical data known to the
working group at the time of writing but, since a wide field is covered, it has been impracticable to
consider every possible factor or circumstance that can potentially affect the implementation of the
recommendations.
It has been assumed in the preparation of this document that the execution of its provisions is entrusted
to people appropriately qualified and experienced in the specification, design, installation, testing,
approval, inspection, operation and maintenance of systems and equipment, for whose guidance it has
been prepared, and who can be expected to exercise a duty of care to avoid unnecessary release of
extinguishant.
Attention is drawn to the Montreal Protocol on substances that deplete the ozone layer and those that
contribute towards climate change.
It is important to consider the fire protection of a building or plant as a whole. Gaseous extinguishant
systems form only a part of the available facilities. It should not be assumed that their adoption removes
the need to consider supplementary measures, for example, the provision of portable fire extinguishers
or other mobile appliances for first aid, emergency use or for dealing with special hazards.
Gaseous extinguishants have been a recognized effective medium for the extinction of flammable liquid
fires and fires in the presence of electrical and ordinary Class A hazards for many years. However, in
the planning of comprehensive schemes, it should be remembered that these media are not suitable for
all hazards. Additionally, in certain circumstances or situations there can be dangers relating to their
use which require special precautions.
Advice on these matters can be obtained from the appropriate manufacturer of the extinguishant or the
extinguishing system. Information may also be sought from the appropriate fire authority, the health
and safety authorities and insurers. Also, reference should be made as necessary to other national
standards and statutory regulations of the particular country.
It is essential that fire-fighting equipment be carefully maintained to ensure instant readiness when
required. Routine maintenance is liable to be overlooked or given insufficient attention by the owner
of the system. It is, however, neglected at peril to the lives of occupants of the premises and the risk of
crippling financial loss. The importance of maintenance cannot be too highly emphasized. Installation
and maintenance should only be done by qualified personnel.
Inspection, preferably by a third party, shoul
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.