ISO 14520-1:2006

INTERNATIONAL ISO
STANDARD 14520-1
Second edition
2006-02-15
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 14520-1:2006(E)
©
ISO 2006

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ISO 14520-1:2006(E)
PDF disclaimer
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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.
© ISO 2006
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
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
©
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ISO 14520-1:2006(E)
Contents Page
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Use and limitations . 5
5 Safety . 7
6 System design . 10
7 Extinguishant system design . 16
8 Commissioning and acceptance . 24
9 Inspection, maintenance, testing and training . 27
Annex A (normative) Working documents . 30
Annex B (normative) Determination of flame-extinguishing concentration of gaseous
extinguishants by the cup burner method . 32
Annex C (normative) Fire extinguishment/area coverage fire test procedure for engineered
and pre-engineered extinguishing units . 38
Annex D (normative) Method of evaluating inerting concentration of a fire extinguishant . 58
Annex E (normative) Door fan test for determining of minimum hold time . 60
Annex F (informative) System performance verification . 75
Annex G (informative) Safe personnel exposure guidelines . 76
Annex H (informative) Flow calculation implementation method and flow calculation verification
and testing for approvals . 83
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ISO 14520-1:2006(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.
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 14520-1 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 second edition cancels and replaces the first edition (ISO 14520-1:2000), which has been technically
revised.
Annex C has been extensively revised to include polymeric sheet fuel array fire tests [polymethyl methacrylate
(PMMA)], [polypropylene (PP)] and [acrylonitrile-butadiene-styrene (ABS)]. These tests are designed to more
closely represent plastic fuel hazards such as may be encountered in information technology,
telecommunications and process control facilities.
Annex E has been re-structured to accommodate lighter-than-air gases and to provide means for dealing with
non-standard (as opposed to geometrically regular) hazard enclosures.
Also incorporated in this revision of ISO 14520-1 are safe personnel exposure guidelines. Annex G, recognizing
physiologically based pharmacokinetic (PBPK) modelling and hypoxic guidelines to define safe human
exposure limits.
ISO 14520 consists of the following parts, under the general title Gaseous fire-extinguishing systems —
Physical properties and system design:
— Part 1: General requirements
— Part 2: CF I extinguishant
3
— Part 5: FK-5-1-12 extinguishant
— Part 6: HCFC Blend A extinguishant
— Part 8: HFC 125 extinguishant
— Part 9: HFC 227ea extinguishant
— Part 10: HFC 23 extinguishant
— Part 11: HFC 236fa extinguishant
— Part 12: IG-01 extinguishant
— Part 13: IG-100 extinguishant
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ISO 14520-1:2006(E)
— Part 14: IG-55 extinguishant
— Part 15: IG-541 extinguishant
Parts 3, 4 and 7, which dealt with FC-2-1-8, FC-3-1-10 and HCFC 124 extinguishants, respectively, have been
withdrawn, as these types are no longer manufactured.
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ISO 14520-1:2006(E)
Introduction
Fire fighting systems covered in this part of ISO14520 are designed to provide 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 part of ISO 14520 has been prepared to meet this need.
In particular, new requirements to eliminate the need to release extinguishants during testing and
commissioning procedures are included. These are linked to the inclusion of enclosure integrity testing.
The requirements of this part of ISO 14520 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 might affect implementation of the recommendations.
It has been assumed in the preparation of this part of ISO 14520 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.
It is important that the fire protection of a building or plant be considered as a whole. Gaseous extinguishant
systems form only a part, though an important part, of the available facilities, but it should not be assumed that
their adoption necessarily removes the need to consider supplementary measures, such as the provision of
portable fire extinguishers or other mobile appliances for first aid or emergency use, or to deal with special
hazards.
Gaseous extinguishants have for many years been a recognized effective medium for the extinction of
inflammable liquid fires and fires in the presence of electrical and ordinary Class A hazards, but it should not be
forgotten, in the planning of comprehensive schemes, that there may be hazards for which these media are not
suitable, or that in certain circumstances or situations there may be dangers in their use requiring 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. In addition, 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 at 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, should include an evaluation that the extinguishing system continues to
provide adequate protection for the risk (protected zones as well as state of the art can change over time).
The test protocol contained in Annex C of this part of ISO 14520 was developed by a special working group of
ISO/TC 21/SC 8. Annex C deals with the tests for determination of the extinguishing concentrations and system
performance and they are designed in such a way to allow individual installers to use his/her/system and carry
out all of the extinguishing tests. The need for the tests presented in Annex C was established by the fact that
the previously used Class A fire test involved wood crib, heptane pan and heptane can test fires in an enclosure
3
of 100 m , and did not necessarily indicate extinguishing concentrations suitable for the protection of plastic fuel
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ISO 14520-1:2006(E)
hazards such as may be encountered in information technology, telecommunications and process control
facilities.
As a consequence of the above, the current Annex C of this part of ISO 14520 has been revised as described
in the Foreword.
Specific parts 3, 4 and 7 have been withdrawn on the basis that the extinguishing media have not been
commercialized, and a new agent specific part5 has been introduced to cover FK-5-1-12
(dodecafluoro-2-methylpentan-3-one) systems.
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INTERNATIONAL STANDARD ISO 14520-1:2006(E)
Gaseous fire-extinguishing systems — Physical properties and
system design —
Part 1:
General requirements
1Scope
This part of ISO 14520 specifies requirements and gives recommendations for the design, installation, testing,
maintenance and safety of gaseous fire fighting systems in buildings, plant 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, plant 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 part of ISO 14520 is not applicable to explosion suppression.
This part of ISO14520 is not intended to indicate approval of the extinguishants listed therein by the
appropriate authorities, as other extinguishants may be equally acceptable. CO is not included as it is covered
2
by other International Standards.
This part of ISO 14520 is applicable to the extinguishants listed in Table 1. It is essential that it be used in
conjunction with the separate parts of ISO 14520 for specific extinguishants, as cited in Table 1.
Table 1 — Listed extinguishant
International
Extinguishant Chemical Formula CAS No.
Standard
CF l Trifluoroiodomethane CF l 2314-97-8 ISO 14520-2
3 3
FK-5-1-12 Dodecafluoro-2-methylpentan-3-one CF CF C(O)CF(CF ) 756-13-8 ISO 14520-5
3 2 3 2
HCFC Blend A
HCFC-123 Dichlorotrifluoroethane CHCl CF 306-83-2
2 3
HCFC-22 Chlorodifluoromethane CHClF 75-45-6 ISO 14520-6
2
HCFC-124 Chlorotetrafluoroethane CFClFCF 2837-89-0
3
Isopropenyl-1-methylcyclohexene C H 5989-27-5
10 16
HFC 125 Pentafluoroethane CHF CF 354-33-6 ISO 14520-8
2 3
HFC 227ea Heptafluoropropane CF CHFCF 2252-84-8 ISO 14520-9
3 3
HFC 23 Trifluoromethane CHF 75-46-7 ISO 14520-10
3
HFC 236fa Hexafluoropropane CF CH CF 27070-61-7 ISO 14520-11
3 2 3
IG-01 Argon Ar 74040-37-1 ISO 14520-12
IG-100 Nitrogen N 7727-37-9 ISO 14520-13
2
Nitrogen (50 %) N 7727-37-9
2
IG-55 Argon (50 %) Ar 74040-37-1 ISO 14520-14
Nitrogen (52 %) N
2
IG-541 Argon (40 %) Ar 74040-37-1 ISO 14520-15
Carbon dioxide (8%) CO 124-38-9
2
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ISO 14520-1:2006(E)
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 3941, Classification of fires
ISO 5660-1, Reaction-to-fire tests — Heat release, smoke production and mass loss rate — Part 1: Heat
release rate (cone calorimeter method)
ISO 14520-2, Gaseous fire-extinguishing systems — Physical properties and system design — Part 2: CF I
3
extinguishant
ISO 14520-5, Gaseous fire-extinguishing systems— Physical properties and system design— Part5:
FK-5-1-12 extinguishant
ISO 14520-6, Gaseous fire-extinguishing systems — Physical properties and system design — Part 6: HCFC
Blend A extinguishant
ISO 14520-8, Gaseous fire-extinguishing systems— Physical properties and system design— Part8:
HFC 125 extinguishant
ISO 14520-9, Gaseous fire-extinguishing systems— Physical properties and system design— Part9:
HFC 227ea extinguishant
ISO 14520-10, Gaseous fire-extinguishing systems— Physical properties and system design— Part10:
HFC 23 extinguishant
ISO 14520-11, Gaseous fire-extinguishing systems— Physical properties and system design— Part11:
HFC 236fa extinguishant
ISO 14520-12, Gaseous fire-extinguishing systems — Physical properties and system design — Part 12: IG-01
extinguishant
ISO 14520-13, Gaseous fire-extinguishing systems— Physical properties and system design— Part13:
IG-100 extinguishant
ISO 14520-14, Gaseous fire-extinguishing systems — Physical properties and system design — Part 14: IG-55
extinguishant
ISO 14520-15, Gaseous fire-extinguishing systems— Physical properties and system design— Part15:
IG-541 extinguishant
ASTM E1354-04a, Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products
Using an Oxygen Consumption Calorimeter
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
NOTE For the purposes of this document, the term “bar” shall be taken as “gauge”, unless otherwise indicated.
Concentrations or quantities expressed in percentages (%) shall be taken as by volume, unless otherwise indicated.
3.1
approved
acceptable to a relevant authority (see 3.2)
NOTE In determining the acceptability of installations or procedures, equipment or materials, the authority can base
acceptance on compliance with the appropriate standards.
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ISO 14520-1:2006(E)
3.2
authority
organization, office or individual responsible for approving equipment, installations or procedures
3.3
automatic/manual switch
means of converting the system from automatic to manual actuation
NOTE This can be in the form of a manual switch on the control panel or other units, or a personnel door interlock. In all
cases, this changes the actuation mode of the system from automatic and manual to manual only or vice versa.
3.4
extinguishant
electrically non-conducting gaseous fire extinguishant that, upon evaporation, does not leave a residue (see
Table 1)
3.5
clearance
air gap between equipment, including piping and nozzles and unenclosed or uninsulated live electrical
components at other than ground potential
3.6 Concentration
3.6.1
design concentration
concentration of extinguishant, including a safety factor, required for system design purposes
3.6.2
maximum concentration
concentration achieved from the actual extinguishant quantity at the maximum ambient temperature in the
protected area
3.6.3
extinguishing concentration
minimum concentration of extinguishant required to extinguish a fire involving a particular fuel under defined
experimental conditions excluding any safety factor
3.7
engineered system
system in which the supply of extinguishant stored centrally is discharged through a system of pipes and
nozzles in which the size of each section of pipe and nozzle orifice has been calculated in accordance with
relevant parts of ISO 14520
3.8
fill density
mass of extinguishant per unit volume of container
3.9
flooding quantity
mass or volume of extinguishant required to achieve the design concentration within the protected volume
3.10
nett volume
volume enclosed by the building elements around the protected enclosure, minus the volume of any permanent
impermeable building elements within the enclosure
3.11
hold time
period of time during which a concentration of extinguishant greater than the fire extinguishing concentration
surrounds the hazard
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ISO 14520-1:2006(E)
3.12
inspection
visual check to give reasonable assurance that the extinguishing system is fully charged and operable
NOTE This is done by seeing that the system is in place, that it has not been activated or tampered with, and that there is
no obvious physical damage or condition to prevent operation.
3.13
liquefied gas
gas or gas mixture (normally a halocarbon) which is liquid at the container pressurization level at room
◦
temperature (20 C)
3.14
lock-off device
manual shut-off valve installed in the discharge piping downstream of the agent containers or another type of
device that mechanically prevents agent container actuation
NOTE 1 The actuation of this device provides an indication of system isolation.
NOTE 2 The intent is to prevent the discharge of agent into the hazard area when the lock-off device is activated.
3.15
lowest observed adverse effect level
LOAEL
lowest concentration at which an adverse toxicological or physiological effect has been observed
3.16
maintenance
thorough check, comprising a thorough examination and any necessary repair or replacement of system
component, to give maximum assurance that the extinguishing system will operate as intended
3.17
maximum working pressure
equilibrium pressure within a container at the maximum working temperature
NOTE 1 For liquefied gases this is at the maximum fill density and can include superpressurization.
NOTE 2 The equilibrium pressure for a container in transit can differ from that in storage within a building.
3.18
no observed adverse effect level
NOAEL
highest concentration at which no adverse toxicological or physiological effect has been observed
3.19
non-liquefied gas
gas or gas mixture (normally an inert gas) which, under service pressure and permissible service temperature
conditions, is always present in the gaseous form
3.20
normally occupied area
area intended for occupancy
3.21
normally unoccupied area
area not normally occupied by people but which may be entered occasionally for brief periods
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ISO 14520-1:2006(E)
3.22
pre-engineered systems
system consisting of a supply of extinguishant of specified capacity coupled to pipework with a balanced nozzle
arrangement up to a maximum permitted design
NOTE No deviation is permitted from the limits specified by the manufacturer or authority.
3.23
safety factor
multiplier of the agent extinguishing concentration to determine the agent minimum design concentration
3.24
sea level equivalent of agent
the agent concentration (volume percent) at sea level for which the partial pressure of agent matches the
ambient partial pressure of agent at a given altitude
3.25
sea level equivalent of oxygen
the oxygen concentration (volume percent) at sea level for which the partial pressure of oxygen matches the
ambient partial pressure of oxygen at a given altitude
3.26
selector valve
valve installed in the discharge piping downstream of the agent containers, to direct the agent to the appropriate
hazard enclosure
NOTE It is used where one or more agent containers are arranged in order to selectively discharge agent to any of several
separate hazard enclosures.
3.27
superpressurization
addition of a gas to the extinguishant container, where necessary, to achieve the required pressure for proper
system operation
3.28
total flooding system
system arranged to discharge extinguishant into an enclosed space to achieve the appropriate design
concentration
3.29
unoccupiable area
area which cannot be occupied due to dimensional or other physical constraints
EXAMPLE Shallow voids and cabinets.
4 Use and limitations
4.1 General
Throughout this part of ISO 14520 the word “shall” indicates a mandatory requirement; the word "should"
indicates a recommendation or that which is advised but not required.
The design, installation, service and maintenance of gaseous fire-extinguishing systems shall be performed by
those competent in fire extinguishing system technology. Maintenance and installation shall only be done by
qualified personnel and companies.
The hazards against which these systems offer protection, and any limitations on their use, shall be contained
in the system supplier's design manual.
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ISO 14520-1:2006(E)
Total flooding fire-extinguishing systems are used primarily for protection against hazards that are in enclosures
or equipment that, in itself, includes an enclosure to contain the extinguishant. The following are typical of such
hazards, but the list is not exhaustive:
a) electrical and electronic hazards;
b) telecommunications facilities;
c) inflammable and combustible liquids and gases;
d) other high-value assets.
4.2 Extinguishants
Any agent that is to be recognized by this part of ISO 14520 or proposed for inclusion in this part of ISO 14520,
shall first be evaluated in a manner equivalent to the process used by the U.S. Environmental Protection
Agency's (EPA) SNAP Programme or other internationally recognized extinguishing agent approval institutions.
The extinguishants referred to in this part of ISO 14520 are electrically non-conductive media.
The extinguishants and specialized system parameters are each covered individually in the parts of ISO 14520
for specific extinguishants. These parts shall be used in conjunction with this part of ISO 14520.
Unless relevant testing has been carried out to the satisfaction of the authority, the extinguishants referred to in
the specific parts of ISO 14520 shall not be used on fires involving the following:
a) chemicals containing their own supply of oxygen, such as cellulose nitrate;
b) mixtures containing oxidizing materials, such as sodium chlorate or sodium nitrate;
c) chemicals capable of undergoing autothermal decomposition, such as some organic peroxides;
d) reactive metals (such as sodium, potassium, magnesium, titanium and zirconium), reactive hydrides, or
metal amides, some of which may react violently with some gaseous extinguishants;
e) environments where significant surface areas exist at temperatures greater than the breakdown
temperature of the extinguishing agent and are heated by means other than the fire.
4.3 Electrostatic discharge
Care shall be taken when discharging extinguishant into potentially explosive atmospheres. Electrostatic
charging of conductors not bonded to earth may occur during the discharge of extinguishant. These conductors
may discharge to other objects with sufficient energy to initiate an explosion. Where the system is used for
inerting, pipework shall be adequately bonded and earthed.
4.4 Compatibility with other extinguishants
Mixing of extinguishants in the same container shall be permitted only if the system is approved for use with
such a mixture.
Systems using the simultaneous discharge of different extinguishants to protect the same enclosed space shall
not be permitted.
4.5 Temperature limitations
All devices shall be designed for the service they will encounter and shall not readily be rendered inoperative or
◦
susceptible to accidental operation. Devices normally shall be designed to function properly from −20 C to
◦
+50 C, or marked to indicate temperature limitations, or in accordance with manufacturers' specifications
which shall be marked on the name-plate, or (where there is no name-plate) in the manufacturer's instruction
manual.
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ISO 14520-1:2006(E)
5 Safety
5.1 Hazard to personnel
Any hazard to personnel created by the discharge of gaseous extinguishants shall be considered in the design
of the system, in particular with reference to the hazards associated with particular extinguishants in the
supplementary parts of ISO 14520. Unnecessary exposure to all gaseous extinguishants shall be avoided.
Adherence to ISO 14520 does not remove the user's statutory responsibility to comply with the appropriate
safety regulations.
The decomposition products generated by the clean agent breaking down in the presence of very high degrees
of heat can be hazardous. All of the present halocarbon agents contain fluorine. In the presence of available
hydrogen (from water vapour, or the combustion process itself), the main decomposition product is hydrogen
fluoride (HF).
These decomposition products have a sharp, acrid odour, even in minute concentrations of only a few parts per
million. This characteristic provides a built-in warning system for the agent, but at the same time creates a
noxious, irritating atmosphere for those who must enter the hazard following a fire.
The amount of agent that can be expected to decompose in extinguishing a fire depends to a large extent on the
size of the fire, the particular clean agent, the concentration of the agent, and the length of time the agent is in
contact with the flame or heated surface. If there is a very rapid build-up of concentration to the critical value,
then the fire will be extinguished quickly and the decomposition will be limited to the minimum possible with that
agent. Should that agent's specific composition be such that it could generate large quantities of decomposition
products, and the time to achieve the critical value is lengthy, then the quantity of decomposition products can
be quite great. The actual concentration of the decomposition products then depends on the volume of the room
in which the fire was burning and on the degree of mixing and ventilation.
Clearly, longer exposure of the agent to high temperatures would produce greater concentrations of these
gases. The type and sensitivity of detection, coupled with the rate of discharge, should be selected to minimize
the exposure time of the agent to the elevated temperature if the concentration of the breakdown products is to
be minimized.
Non-liquefied agents do not decompose measurably in exti
...

SLOVENSKI STANDARD
SIST ISO 14520-1:2006
01-november-2006
Naprave za gašenje s plinom - Fizikalne lastnosti in projektiranje - 1. del: Splošne
zahteve
Gaseous fire-extinguishing systems - Physical properties and system design - Part 1:
General requirements
Ta slovenski standard je istoveten z:
ICS:
13.220.10 Gašenje požara Fire-fighting
SIST ISO 14520-1:2006 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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INTERNATIONAL ISO
STANDARD 14520-1
Second edition
2006-02-15
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 14520-1:2006(E)
©
ISO 2006

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ISO 14520-1:2006(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.
© ISO 2006
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
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
©
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ISO 14520-1:2006(E)
Contents Page
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Use and limitations . 5
5 Safety . 7
6 System design . 10
7 Extinguishant system design . 16
8 Commissioning and acceptance . 24
9 Inspection, maintenance, testing and training . 27
Annex A (normative) Working documents . 30
Annex B (normative) Determination of flame-extinguishing concentration of gaseous
extinguishants by the cup burner method . 32
Annex C (normative) Fire extinguishment/area coverage fire test procedure for engineered
and pre-engineered extinguishing units . 38
Annex D (normative) Method of evaluating inerting concentration of a fire extinguishant . 58
Annex E (normative) Door fan test for determining of minimum hold time . 60
Annex F (informative) System performance verification . 75
Annex G (informative) Safe personnel exposure guidelines . 76
Annex H (informative) Flow calculation implementation method and flow calculation verification
and testing for approvals . 83
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ISO 14520-1:2006(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.
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 14520-1 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 second edition cancels and replaces the first edition (ISO 14520-1:2000), which has been technically
revised.
Annex C has been extensively revised to include polymeric sheet fuel array fire tests [polymethyl methacrylate
(PMMA)], [polypropylene (PP)] and [acrylonitrile-butadiene-styrene (ABS)]. These tests are designed to more
closely represent plastic fuel hazards such as may be encountered in information technology,
telecommunications and process control facilities.
Annex E has been re-structured to accommodate lighter-than-air gases and to provide means for dealing with
non-standard (as opposed to geometrically regular) hazard enclosures.
Also incorporated in this revision of ISO 14520-1 are safe personnel exposure guidelines. Annex G, recognizing
physiologically based pharmacokinetic (PBPK) modelling and hypoxic guidelines to define safe human
exposure limits.
ISO 14520 consists of the following parts, under the general title Gaseous fire-extinguishing systems —
Physical properties and system design:
— Part 1: General requirements
— Part 2: CF I extinguishant
3
— Part 5: FK-5-1-12 extinguishant
— Part 6: HCFC Blend A extinguishant
— Part 8: HFC 125 extinguishant
— Part 9: HFC 227ea extinguishant
— Part 10: HFC 23 extinguishant
— Part 11: HFC 236fa extinguishant
— Part 12: IG-01 extinguishant
— Part 13: IG-100 extinguishant
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ISO 14520-1:2006(E)
— Part 14: IG-55 extinguishant
— Part 15: IG-541 extinguishant
Parts 3, 4 and 7, which dealt with FC-2-1-8, FC-3-1-10 and HCFC 124 extinguishants, respectively, have been
withdrawn, as these types are no longer manufactured.
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ISO 14520-1:2006(E)
Introduction
Fire fighting systems covered in this part of ISO14520 are designed to provide 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 part of ISO 14520 has been prepared to meet this need.
In particular, new requirements to eliminate the need to release extinguishants during testing and
commissioning procedures are included. These are linked to the inclusion of enclosure integrity testing.
The requirements of this part of ISO 14520 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 might affect implementation of the recommendations.
It has been assumed in the preparation of this part of ISO 14520 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.
It is important that the fire protection of a building or plant be considered as a whole. Gaseous extinguishant
systems form only a part, though an important part, of the available facilities, but it should not be assumed that
their adoption necessarily removes the need to consider supplementary measures, such as the provision of
portable fire extinguishers or other mobile appliances for first aid or emergency use, or to deal with special
hazards.
Gaseous extinguishants have for many years been a recognized effective medium for the extinction of
inflammable liquid fires and fires in the presence of electrical and ordinary Class A hazards, but it should not be
forgotten, in the planning of comprehensive schemes, that there may be hazards for which these media are not
suitable, or that in certain circumstances or situations there may be dangers in their use requiring 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. In addition, 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 at 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, should include an evaluation that the extinguishing system continues to
provide adequate protection for the risk (protected zones as well as state of the art can change over time).
The test protocol contained in Annex C of this part of ISO 14520 was developed by a special working group of
ISO/TC 21/SC 8. Annex C deals with the tests for determination of the extinguishing concentrations and system
performance and they are designed in such a way to allow individual installers to use his/her/system and carry
out all of the extinguishing tests. The need for the tests presented in Annex C was established by the fact that
the previously used Class A fire test involved wood crib, heptane pan and heptane can test fires in an enclosure
3
of 100 m , and did not necessarily indicate extinguishing concentrations suitable for the protection of plastic fuel
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ISO 14520-1:2006(E)
hazards such as may be encountered in information technology, telecommunications and process control
facilities.
As a consequence of the above, the current Annex C of this part of ISO 14520 has been revised as described
in the Foreword.
Specific parts 3, 4 and 7 have been withdrawn on the basis that the extinguishing media have not been
commercialized, and a new agent specific part5 has been introduced to cover FK-5-1-12
(dodecafluoro-2-methylpentan-3-one) systems.
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INTERNATIONAL STANDARD ISO 14520-1:2006(E)
Gaseous fire-extinguishing systems — Physical properties and
system design —
Part 1:
General requirements
1Scope
This part of ISO 14520 specifies requirements and gives recommendations for the design, installation, testing,
maintenance and safety of gaseous fire fighting systems in buildings, plant 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, plant 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 part of ISO 14520 is not applicable to explosion suppression.
This part of ISO14520 is not intended to indicate approval of the extinguishants listed therein by the
appropriate authorities, as other extinguishants may be equally acceptable. CO is not included as it is covered
2
by other International Standards.
This part of ISO 14520 is applicable to the extinguishants listed in Table 1. It is essential that it be used in
conjunction with the separate parts of ISO 14520 for specific extinguishants, as cited in Table 1.
Table 1 — Listed extinguishant
International
Extinguishant Chemical Formula CAS No.
Standard
CF l Trifluoroiodomethane CF l 2314-97-8 ISO 14520-2
3 3
FK-5-1-12 Dodecafluoro-2-methylpentan-3-one CF CF C(O)CF(CF ) 756-13-8 ISO 14520-5
3 2 3 2
HCFC Blend A
HCFC-123 Dichlorotrifluoroethane CHCl CF 306-83-2
2 3
HCFC-22 Chlorodifluoromethane CHClF 75-45-6 ISO 14520-6
2
HCFC-124 Chlorotetrafluoroethane CFClFCF 2837-89-0
3
Isopropenyl-1-methylcyclohexene C H 5989-27-5
10 16
HFC 125 Pentafluoroethane CHF CF 354-33-6 ISO 14520-8
2 3
HFC 227ea Heptafluoropropane CF CHFCF 2252-84-8 ISO 14520-9
3 3
HFC 23 Trifluoromethane CHF 75-46-7 ISO 14520-10
3
HFC 236fa Hexafluoropropane CF CH CF 27070-61-7 ISO 14520-11
3 2 3
IG-01 Argon Ar 74040-37-1 ISO 14520-12
IG-100 Nitrogen N 7727-37-9 ISO 14520-13
2
Nitrogen (50 %) N 7727-37-9
2
IG-55 Argon (50 %) Ar 74040-37-1 ISO 14520-14
Nitrogen (52 %) N
2
IG-541 Argon (40 %) Ar 74040-37-1 ISO 14520-15
Carbon dioxide (8%) CO 124-38-9
2
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ISO 14520-1:2006(E)
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 3941, Classification of fires
ISO 5660-1, Reaction-to-fire tests — Heat release, smoke production and mass loss rate — Part 1: Heat
release rate (cone calorimeter method)
ISO 14520-2, Gaseous fire-extinguishing systems — Physical properties and system design — Part 2: CF I
3
extinguishant
ISO 14520-5, Gaseous fire-extinguishing systems— Physical properties and system design— Part5:
FK-5-1-12 extinguishant
ISO 14520-6, Gaseous fire-extinguishing systems — Physical properties and system design — Part 6: HCFC
Blend A extinguishant
ISO 14520-8, Gaseous fire-extinguishing systems— Physical properties and system design— Part8:
HFC 125 extinguishant
ISO 14520-9, Gaseous fire-extinguishing systems— Physical properties and system design— Part9:
HFC 227ea extinguishant
ISO 14520-10, Gaseous fire-extinguishing systems— Physical properties and system design— Part10:
HFC 23 extinguishant
ISO 14520-11, Gaseous fire-extinguishing systems— Physical properties and system design— Part11:
HFC 236fa extinguishant
ISO 14520-12, Gaseous fire-extinguishing systems — Physical properties and system design — Part 12: IG-01
extinguishant
ISO 14520-13, Gaseous fire-extinguishing systems— Physical properties and system design— Part13:
IG-100 extinguishant
ISO 14520-14, Gaseous fire-extinguishing systems — Physical properties and system design — Part 14: IG-55
extinguishant
ISO 14520-15, Gaseous fire-extinguishing systems— Physical properties and system design— Part15:
IG-541 extinguishant
ASTM E1354-04a, Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products
Using an Oxygen Consumption Calorimeter
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
NOTE For the purposes of this document, the term “bar” shall be taken as “gauge”, unless otherwise indicated.
Concentrations or quantities expressed in percentages (%) shall be taken as by volume, unless otherwise indicated.
3.1
approved
acceptable to a relevant authority (see 3.2)
NOTE In determining the acceptability of installations or procedures, equipment or materials, the authority can base
acceptance on compliance with the appropriate standards.
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ISO 14520-1:2006(E)
3.2
authority
organization, office or individual responsible for approving equipment, installations or procedures
3.3
automatic/manual switch
means of converting the system from automatic to manual actuation
NOTE This can be in the form of a manual switch on the control panel or other units, or a personnel door interlock. In all
cases, this changes the actuation mode of the system from automatic and manual to manual only or vice versa.
3.4
extinguishant
electrically non-conducting gaseous fire extinguishant that, upon evaporation, does not leave a residue (see
Table 1)
3.5
clearance
air gap between equipment, including piping and nozzles and unenclosed or uninsulated live electrical
components at other than ground potential
3.6 Concentration
3.6.1
design concentration
concentration of extinguishant, including a safety factor, required for system design purposes
3.6.2
maximum concentration
concentration achieved from the actual extinguishant quantity at the maximum ambient temperature in the
protected area
3.6.3
extinguishing concentration
minimum concentration of extinguishant required to extinguish a fire involving a particular fuel under defined
experimental conditions excluding any safety factor
3.7
engineered system
system in which the supply of extinguishant stored centrally is discharged through a system of pipes and
nozzles in which the size of each section of pipe and nozzle orifice has been calculated in accordance with
relevant parts of ISO 14520
3.8
fill density
mass of extinguishant per unit volume of container
3.9
flooding quantity
mass or volume of extinguishant required to achieve the design concentration within the protected volume
3.10
nett volume
volume enclosed by the building elements around the protected enclosure, minus the volume of any permanent
impermeable building elements within the enclosure
3.11
hold time
period of time during which a concentration of extinguishant greater than the fire extinguishing concentration
surrounds the hazard
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ISO 14520-1:2006(E)
3.12
inspection
visual check to give reasonable assurance that the extinguishing system is fully charged and operable
NOTE This is done by seeing that the system is in place, that it has not been activated or tampered with, and that there is
no obvious physical damage or condition to prevent operation.
3.13
liquefied gas
gas or gas mixture (normally a halocarbon) which is liquid at the container pressurization level at room
◦
temperature (20 C)
3.14
lock-off device
manual shut-off valve installed in the discharge piping downstream of the agent containers or another type of
device that mechanically prevents agent container actuation
NOTE 1 The actuation of this device provides an indication of system isolation.
NOTE 2 The intent is to prevent the discharge of agent into the hazard area when the lock-off device is activated.
3.15
lowest observed adverse effect level
LOAEL
lowest concentration at which an adverse toxicological or physiological effect has been observed
3.16
maintenance
thorough check, comprising a thorough examination and any necessary repair or replacement of system
component, to give maximum assurance that the extinguishing system will operate as intended
3.17
maximum working pressure
equilibrium pressure within a container at the maximum working temperature
NOTE 1 For liquefied gases this is at the maximum fill density and can include superpressurization.
NOTE 2 The equilibrium pressure for a container in transit can differ from that in storage within a building.
3.18
no observed adverse effect level
NOAEL
highest concentration at which no adverse toxicological or physiological effect has been observed
3.19
non-liquefied gas
gas or gas mixture (normally an inert gas) which, under service pressure and permissible service temperature
conditions, is always present in the gaseous form
3.20
normally occupied area
area intended for occupancy
3.21
normally unoccupied area
area not normally occupied by people but which may be entered occasionally for brief periods
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ISO 14520-1:2006(E)
3.22
pre-engineered systems
system consisting of a supply of extinguishant of specified capacity coupled to pipework with a balanced nozzle
arrangement up to a maximum permitted design
NOTE No deviation is permitted from the limits specified by the manufacturer or authority.
3.23
safety factor
multiplier of the agent extinguishing concentration to determine the agent minimum design concentration
3.24
sea level equivalent of agent
the agent concentration (volume percent) at sea level for which the partial pressure of agent matches the
ambient partial pressure of agent at a given altitude
3.25
sea level equivalent of oxygen
the oxygen concentration (volume percent) at sea level for which the partial pressure of oxygen matches the
ambient partial pressure of oxygen at a given altitude
3.26
selector valve
valve installed in the discharge piping downstream of the agent containers, to direct the agent to the appropriate
hazard enclosure
NOTE It is used where one or more agent containers are arranged in order to selectively discharge agent to any of several
separate hazard enclosures.
3.27
superpressurization
addition of a gas to the extinguishant container, where necessary, to achieve the required pressure for proper
system operation
3.28
total flooding system
system arranged to discharge extinguishant into an enclosed space to achieve the appropriate design
concentration
3.29
unoccupiable area
area which cannot be occupied due to dimensional or other physical constraints
EXAMPLE Shallow voids and cabinets.
4 Use and limitations
4.1 General
Throughout this part of ISO 14520 the word “shall” indicates a mandatory requirement; the word "should"
indicates a recommendation or that which is advised but not required.
The design, installation, service and maintenance of gaseous fire-extinguishing systems shall be performed by
those competent in fire extinguishing system technology. Maintenance and installation shall only be done by
qualified personnel and companies.
The hazards against which these systems offer protection, and any limitations on their use, shall be contained
in the system supplier's design manual.
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ISO 14520-1:2006(E)
Total flooding fire-extinguishing systems are used primarily for protection against hazards that are in enclosures
or equipment that, in itself, includes an enclosure to contain the extinguishant. The following are typical of such
hazards, but the list is not exhaustive:
a) electrical and electronic hazards;
b) telecommunications facilities;
c) inflammable and combustible liquids and gases;
d) other high-value assets.
4.2 Extinguishants
Any agent that is to be recognized by this part of ISO 14520 or proposed for inclusion in this part of ISO 14520,
shall first be evaluated in a manner equivalent to the process used by the U.S. Environmental Protection
Agency's (EPA) SNAP Programme or other internationally recognized extinguishing agent approval institutions.
The extinguishants referred to in this part of ISO 14520 are electrically non-conductive media.
The extinguishants and specialized system parameters are each covered individually in the parts of ISO 14520
for specific extinguishants. These parts shall be used in conjunction with this part of ISO 14520.
Unless relevant testing has been carried out to the satisfaction of the authority, the extinguishants referred to in
the specific parts of ISO 14520 shall not be used on fires involving the following:
a) chemicals containing their own supply of oxygen, such as cellulose nitrate;
b) mixtures containing oxidizing materials, such as sodium chlorate or sodium nitrate;
c) chemicals capable of undergoing autothermal decomposition, such as some organic peroxides;
d) reactive metals (such as sodium, potassium, magnesium, titanium and zirconium), reactive hydrides, or
metal amides, some of which may react violently with some gaseous extinguishants;
e) environments where significant surface areas exist at temperatures greater than the breakdown
temperature of the extinguishing agent and are heated by means other than the fire.
4.3 Electrostatic discharge
Care shall be taken when discharging extinguishant into potentially explosive atmospheres. Electrostatic
charging of conductors not bonded to earth may occur during the discharge of extinguishant. These conductors
may discharge to other objects with sufficient energy to initiate an explosion. Where the system is used for
inerting, pipework shall be adequately bonded and earthed.
4.4 Compatibility with other extinguishants
Mixing of extinguishants in the same container shall be permitted only if the system is approved for use with
such a mixture.
Systems using the simultaneous discharge of different extinguishants to protect the same enclosed space shall
not be permitted.
4.5 Temperature limitations
All devices shall be designed for the service they will encounter and shall not readily be rendered inoperative or
◦
susceptible to accidental operation. Devices normally shall be designed to function properly from −20 C to
◦
+50 C, or marked to indicate temperature limitations, or in accordance with manufacturers' specifications
which shall be marked on the name-plate, or (where there is no name-plate) in the manufacturer's instruction
manual.
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ISO 14520-1:2006(E)
5 Safety
5.1 Hazard to personnel
Any hazard to personnel created by the discharge of gaseous extinguishants shall be considered in the design
of the system, in particular with reference to the hazards associated with particular extinguishants in the
supplementary parts of ISO 14520. Unnecessary exposure to all gaseous extinguishants shall be avoided.
Adherence to ISO 14520 does not remove the user's statutory responsibility to comply with the appropriate
safety regulations.
The decomposition products generated by the clean agent breaking down in the presence of very high degrees
of heat can be hazardous. All of the present halocarbon agents contain fluorine. In the presence of available
hydrogen (from water vapour, or the combustion process itself), the main decomposition product is hydrogen
fluoride (HF).
These decomposition products have a sharp, acrid odour, even in minute concentrations of only a few parts per
million. This characteristic provides a built-in warning system for the agent, but at the same time creates a
noxious, irritating atmosphere for those who must enter the hazard following a fire.
The amount of agent that can be expected to decompose in extinguishing a fire depends to a large extent on the
size of the fire, the particular clean agent, the concentration of the agent, and the length of time the agent is in
contact with the flame or heated surface. If there is a very rapid build-up of concentration to the critical value,
then the fire will be extinguished quickly and the decomposition will be limited to the minimum possible with that
agent. Should that agent's specific composition be such that it could generate large quantities of decomposition
products, and the time to achieve the critical value is lengthy, then the quantity of decomposition products can
be quite great. The actu
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