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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 document was developed by a special working group of ISO/ТС 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 of minimum 100 m³, and did not necessarily indicate extinguishing concentrations suitable for the protection of plastic fuel hazards such as may be encountered in information technology, telecommunications and process control facilities.

1. As a consequence of the above, the current Annex C of this document has been revised as described in the Foreword.Scope

This document specifies requirements and gives recommendations for the design, installation, testing, maintenance and safety of gaseous fire fighting 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 is not applicable to explosion suppression.

This document is not intended to indicate approval of the extinguishants listed therein by the appropriate authorities, as other extinguishants may be equally acceptable. CO2 is not included as it is covered by other International Standards.

This document is applicable to the extinguishants listed in Table 1. It is intended to be used in conjunction with the separate parts of EN 15004 for specific extinguishants, as cited in Table 1.

Table 1 —Listed extinguishants

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.

EN 2, Classification offices

EN 54 (all parts), Fire detection and fire alarm systems

EN 12094-1, Fixed firefighting systems - Components for gas extinguishing systems - Part 1: Requirements and test methods for electrical automatic control and delay devices

EN 12094-2, Fixed firefighting systems - Components for gas extinguishing systems - Part 2: Requirements and test methods for поп-electrical automatic control and delay devices

EN 12094-3, Fixed firefighting systems - Components for gas extinguishing systems - Part 3: Requirements and test methods for manual triggering and stop devices

EN 12094-4, Fixed firefighting systems - Components for gas extinguishing systems - Part 4: Requirements and test methods for container valve assemblies and their actuators

EN 12094-5, Fixed firefighting systems - Components for gas extinguishing systems - Part 5: Requirements and test methods for high and low pressure selector valves and their actuators

EN 12094-6, Fixed firefighting systems - Components for gas extinguishing systems - Part 6: Requirements and test methods for поп-electrical disable devices

EN 12094-7, Fixed firefighting systems - Components for gas extinguishing systems - Part 7: Requirements and test methods for nozzles for C02 systems

EN 12094-8, Fixed firefighting systems - Components for gas extinguishing systems - Part 8: Requirements and test methods for connectors

EN 12094-10, Fixed firefighting systems - Components for gas extinguishing systems - Part 10: Requirements and test methods for pressure gauges and pressure switches

EN 12094-11, Fixed firefighting systems - Components for gas extinguishing systems - Part 11: Requirements and test methods for mechanical weighing devices

EN 12094-13, Fixed firefighting systems - Components for gas extinguishing systems - Part 13: Requirements and test methods for check valves and non-return valves

EN 15004-2:2008, Fixed firefighting systems - Gas extinguishing systems - Part 2: Physical properties and system design of gas extinguishing systems for FK-5-1-12, extinguishant (ISO 14520-5, modified)

EN 15004-3:2008, Fixed firefighting systems - Gas extinguishing systems - Part 3: Physical properties and system design of gas extinguishing systems forHCFC Blend A extinguishant (ISO 14250-6, modified)

EN 15004-4,:2008 Fixed firefighting systems - Gas extinguishing systems - Part 4: Physical properties and system design of gas extinguishing systems forHFC 125 extinguishant (ISO 14520-8, modified)

EN 15004-5:2008, Fixed firefighting systems - Gas extinguishing systems - Part 5: Physical properties and system design of gas extinguishing systems forHFC 227ea extinguishant (ISO 14520-9, modified)

EN 15004-6:2008, Fixed firefighting systems - Gas extinguishing systems - Part 6: Physical properties and system design of gas extinguishing systems forHFC 23 extinguishant (ISO 14520-10, modified)

EN 15004-7:2008, Fixed firefighting systems - Gas extinguishing systems - Part 7: Physical properties and system design of gas extinguishing systems forlG-01 extinguishant (ISO 14520-12, modified)

EN 15004-8:2008, Fixed firefighting systems - Gas extinguishing systems - Part 8: Physical properties and system design of gas extinguishing systems for IG-100 extinguishant (ISO 14520-13, modified)

EN 15004-9:2008, Fixed firefighting systems - Gas extinguishing systems - Part 9: Physical properties and system design of gas extinguishing systems forlG-55 extinguishant (ISO 14520-14, modified)

EN 15004-10:2008, Fixed firefighting systems - Gas extinguishing systems - Part 10: Physical properties and system design of gas extinguishing systems forlG-541 extinguishant (ISO 14520-15, modified)

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” is be taken as “gauge”, unless otherwise indicated. Concentrations or quantities expressed in percentages (%) are taken as by volume, unless otherwise indicated.

approved

acceptable to a relevant authority (see 3.2)

NOTE In determining the acceptability of installations or procedures, equipment or materials, the authority may base acceptance on compliance with the appropriate standards.

authority

organization, office or individual responsible for approving equipment, installations or procedures

automatic/manual switch

means of converting the system from automatic to manual actuation

NOTE This may 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.

competent person

designated person, suitably trained, qualified by knowledge and practical experience and with the necessary instructions to enable the required tests and examinations to be carried out

extinguishant

electrically non-conducting gaseous fire extinguishant that, upon evaporation, does not leave a residue (see Table 1)

I 3.6

clearance

air gap between equipment, including piping and nozzles and unenclosed or uninsulated live electrical components at other than ground potential

design concentration

concentration of extinguishant, including a safety factor, required for system design purposes

I 3.7.2

maximum concentration

concentration achieved from the actual extinguishant quantity at the maximum ambient temperature in the protected area

I 3.7.3

extinguishing concentration

minimum concentration of extinguishant required to extinguish a fire involving a particular fuel under defined experimental conditions excluding any safety factor

disable device

manual shut-off valve installed into 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 disable device is activated.

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 EN 15004

I 3.10

fill density

mass of extinguishant per unit volume of container

I 3.11

flooding quantity

mass or volume of extinguishant required to achieve the design concentration within the protected volume

I 3.12

net volume

volume enclosed by the building elements around the protected enclosure, minus the volume of any permanent impermeable building elements within the enclosure

I 3.13

hold time

period of time during which a concentration of extinguishant greater than the fire extinguishing concentration surrounds the hazard

I 3.14

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.

3.15

installer

legal person that is responsible for the design and installation and is able to ensure that the quality assurance is exercised

3.16

liquefied gas

gas or gas mixture (normally a halocarbon) which is liquid at the container pressurization level at room temperature (20 °С)

3.17

lowest observed adverse effect level

LOAEL

lowest concentration at which an adverse toxicological or physiological effect has been observed

3.18

maintenance

combination of all technical, administrative and managerial actions during the life cycle of an item intended to retain it in, or restore it to, a state in which it can perform the required function

(EN 13306 [2])

3.19 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 may include superpressurization.

NOTE 2 The equilibrium pressure for a container in transit can differ from that in storage within a building.

I 3.20 no observed adverse effect level NOAEL highest concentration at which no adverse toxicological or physiological effect has been observed

I 3.21 non-liquefied gas gas or gas mixture (normally an inert gas) which, under service pressure and allowable service temperature conditions, is always present in the gaseous form

I 3.22 normally occupied area area intended for occupancy

I 3.23 normally unoccupied area area not normally occupied by people but which may be entered occasionally for brief periods

I 3.24 pre-engineered system 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.

I 3.25 safety factor multiplier of the agent extinguishing concentration to determine the agent minimum design concentration

I 3.26 sea level equivalent of agent 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

I 3.27 sea level equivalent of oxygen 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

I 3.28 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 to selectively discharge agent to any of several separate hazard enclosures.

I 3.29

superpressurization

addition of a gas to the extinguishant container, where necessary, to achieve the required pressure for proper system operation

I 3.30

total flooding system

system arranged to discharge extinguishant into an enclosed space to achieve the appropriate design concentration

I 3.31

unoccupiable area

area which cannot be occupied due to dimensional or other physical constraints

EXAMPLE Shallow voids and cabinets.

4. Use and limitations

   1. General

The design, installation and activities to ensure proper system function 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.

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:

1. electrical and electronic hazards;

2. telecommunications facilities;

3. flammable and combustible liquids and gases;

4. other high-value assets.

Any agent that is to be recognized by this document or proposed for inclusion in this document, shall first be evaluated in respect to environmental aspects by European or other internationally recognized extinguishing agent approval institutions.

NOTE Evaluation can be carried out e g. in a manner equivalent to the U.S. Environmental Protection Agency's (EPA) SNAP Programme.

The extinguishants referred to in this document are electrically non-conductive media.

The extinguishants and specialized system parameters are each covered individually in the parts of EN 15004 for specific extinguishants. These parts shall be used in conjunction with this document.

Unless relevant testing has been carried out to the satisfaction of the authority, the extinguishants referred to in the specific parts of EN 15004 shall not be used on fires involving the following:

1. chemicals containing their own supply of oxygen, such as cellulose nitrate;

2. mixtures containing oxidizing materials, such as sodium chlorate or sodium nitrate;

3. chemicals capable of undergoing autothermal decomposition, such as some organic peroxides;

4. 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;

5. 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.

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.

Mixing of extinguishants in the same container shall be permitted only if the system is approved for use with such a mixture.

Systems employing the simultaneous discharge of different extinguishants to protect the same enclosed space shall not be permitted.

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 °С to + 50 °С, or marked to indicate temperature limitations, or in accordance with manufacturer's specifications which shall be marked on the name-plate, or (where there is no name-plate) in the manufacturer's instruction manual.

4. Safety

   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 EN 15004. Unnecessary exposure to all gaseous extinguishants shall be avoided.

Adherence to EN 15004 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 have to 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 extinguishing a fire. As such, toxic or corrosive decomposition products are not found. However, breakdown products of the fire itself can still be substantial and could make the area untenable for human occupancy.

As acceptable alternatives to the requirements of 5.2 and 5.3, either the requirements of Annex G for safe personnel exposure guidelines or those requirements specified by appropriate national standards may be followed.

The safety precautions required by this document do not address toxicological or physiological effects associated with the products of combustion caused by fire. The maximum exposure time assumed by the safety precautions in this standard is 5 min. Exposure times longer than 5 min may involve physiological or toxicological effects not addressed by this document.