Duration of protection
It is important that an effective extinguishant concentration not only be achieved, but is maintained for a sufficient period of time to allow effective emergency action. This is equally important in all classes of fires since a persistent ignition source (e.g. an arc, heat source, oxyacetylene torch or "deep-seated" fire) can lead to resurgence of the initial event once the extinguishant has dissipated.
It is essential to determine the likely period during which the extinguishing concentration will be maintained within the protected enclosure. This is known as the hold time. The predicted hold time shall be determined by the door fan test specified in Annex E, or a full discharge test based on the following criteria:
at the start of the hold time, the concentration throughout the enclosure shall be the design concentration;
at the end of the hold time, the extinguishant concentration at 10 %, 50 % and 90 % of the enclosure height shall be not less than 85 % of the design concentration;
the hold time shall be not less than 10 min, unless otherwise specified by the authority.
System performance
Discharge time
Liquefied extinguishant
The liquefied extinguishant discharge shall be completed as quickly as possible to suppress the fire and limit the formation of decomposition products. In no case shall the discharge time required to achieve 95 % of the design concentration exceed 10 s at 20 °С, or as otherwise required by the authority.
The discharge time period is defined as the time required to discharge from the nozzles 95 % of the extinguishant mass required to achieve the design concentration at 20 °С. For liquefied extinguishants, this can be approximated as the interval between the first appearance of liquid at the nozzle and the time when the discharge becomes predominantly gaseous. Flow calculations performed in accordance with 7.3 or with the approved pre-engineered systems instruction manuals shall be used to demonstrate compliance with this clause.
Non-liquefied extinguishant
The discharge time required to achieve 95 % of the design concentration for non-liquefied extinguishants shall not exceed 60 s at 20 °С, or as otherwise required by the authority. Flow calculations performed in accordance with 7.3 or with the approved pre-engineered systems instruction manuals shall be used to demonstrate compliance with this clause.
Extended discharge
When an extended discharge is necessary, the rate shall be sufficient to maintain the desired concentration for the required hold time.
Commissioning and acceptance
General
This clause sets out the minimum requirements for the commissioning and acceptance of the gaseous extinguishing system.
Tests
General
The completed system shall be reviewed and tested by a competent person to meet the approval of the authority. Only equipment and devices designed to national standards shall be used in the systems. To determine that the system has been properly installed and will function as specified, the tests specified in 8.2.2 to 8.2.9 shall be performed.
Enclosure check
Determine that the protected enclosure is in general conformance with the plans.
Review of mechanical components
The piping distribution system shall be inspected to determine that it is in compliance with the design and installation documents.
Nozzles and pipe size and, if appropriate, pressure-reducing devices, shall be in accordance with
system drawings. The means for pipe size reduction and attitudes of tees shall be checked for conformance to the design.
Piping joints, discharge nozzles and piping supports shall be securely fastened to prevent unacceptable vertical or lateral movement during discharge. Discharge nozzles shall be installed in such a manner that piping cannot become detached during discharge.
During assembly, the piping distribution system shall be inspected internally to detect the possibility of any oil or particulate matter which could soil the hazard area or affect the extinguishant distribution due to a reduction in the effective nozzle orifice area.
The discharge nozzles shall be oriented in such a manner that optimum extinguishant dispersal can be effected.
If nozzle deflectors are installed, they shall be positioned to obtain the maximum benefit.
The discharge nozzles, piping, and mounting brackets shall be installed in such a manner that
they will not potentially cause injury to personnel. Extinguishant shall not directly impinge on areas where personnel may be found in the normal work area, or on any loose objects or shelves, cabinet tops, or similar surfaces where loose objects could be present and become missiles.
All extinguishant storage containers shall be properly located in accordance with 'approved for construction' set of system drawings.
All containers and mounting brackets shall be securely fastened in accordance with the manufacturer's requirements.
A discharge test for extinguishants is generally not recommended. However, if a discharge test is to be conducted, the mass of extinguishant shall be determined by weighing or other approved methods. Concentration measurements should be made at a minimum of three points, one at the highest hazard level.
Other assessment methods may normally be used to reduce unnecessary discharge into the environment, for example, the door fan pressurization test specified in Annex E. However, a discharge test may be conducted if acceptable to the authority.
An adequate quantity of extinguishant to produce the desired specified concentration shall be provided. The actual enclosure volumes shall be checked against those indicated on the system drawings to ensure the proper quantity of extinguishant. Fan rundown and damper closure time shall be taken into consideration.
Unless the total piping contains not more than one change in direction fitting between the storage container and the discharge nozzle, and unless all piping has been physically checked for tightness, the following tests shall be carried out:
all open-ended piping shall be pneumatically tested in a closed circuit for a period of 10 min at 3 bar. At the end of 10 min, the pressure drop shall not exceed 20 % of the test pressure;
all closed-section pipework and pipework upstream of pressure reducing devices shall be hydrostatically tested to a minimum of 1,5 x the maximum working pressure for 2 min during which there shall be no leakage. On completion of the test, the pipework shall be purged to remove moisture.
It is recommended that hydrostatic testing be carried out at the manufacturer's works where practicable.
WARNING — Pneumatic pressure testing creates a potential risk of injury to personnel in the area, as a result of airborne projectiles if rupture of the piping system occurs. Prior to conducting the pneumatic pressure test, the protected area shall be evacuated and appropriate safeguards shall be provided for test personnel.
A test using nitrogen, or a suitable alternative, shall be performed on the piping network to verify that flow is continuous and that the piping and nozzles are unobstructed.
Review of enclosure integrity
All total flooding systems shall have the enclosure checked to locate and then effectively seal any significant air leaks that could result in a failure of the enclosure to hold the specified extinguishant concentration level for the specified holding period (see also 7.4.1). Unless otherwise required by the authority, the test specified in Annex E shall be used.
Review of electrical components
All wiring systems shall be properly installed in compliance with the appropriate national standard
and the system drawings. The AC and DC wiring shall not be combined in a common conduit unless properly shielded and earthed.
All field circuitry shall be tested for ground fault and short circuit condition. When testing field circuitry, all electronic components (such as smoke and flame detectors or special electronic equipment for other detectors, or their mounting bases) shall be removed and jumpers properly installed to prevent the possibility of damage within these devices. Replace components after testing the circuits.
Adequate and reliable primary standby sources of energy which comply with 6.4 shall be used to provide for operation of the detection, signalling, control and actuation requirements of the system.
All auxiliary functions (such as alarm sounding or displaying devices, remote annunciators, air handling shutdown, power shutdown, etc.) shall be checked for proper operation in accordance with system requirements and design specifications.
Alarm devices shall be installed so that they are audible and visible under normal operating and environmental conditions.
Where possible, all air-handling and power cut-off controls should be of the type that once interrupted require manual restart to restore power.
Check that for systems using alarm silencing, this function does not affect other auxiliary functions such as air handling or power cut-off where they are required in the design specification.
Check the detection devices to ensure that the types and locations are as specified in the system drawings and are in accordance with the manufacturer's requirements.
Check that manual release devices are properly installed and are readily accessible, accurately identified and properly protected to prevent damage.
Check that all manual release devices used to release extinguishants require two separate and
distinct actions for operation. They shall be properly identified. Particular care shall be taken where manual release devices for more than one system are in close proximity and could be confused or the wrong system actuated. Manual release devices in this instance shall be clearly identified as to which hazard enclosure they protect.
Check that for systems with a main/reserve capability, the main/reserve switch is properly installed, readily accessible and clearly identified.
Check that for systems using stop devices requiring constant manual force, these are properly installed, readily accessible within the hazard area and clearly identified.
Check that the control panel is properly installed and readily accessible.
Preliminary functional tests
Where a system is connected to a remote central alarm station, notify the station that the fire system test is to be conducted and that an emergency response by the fire department or alarm station personnel is not required. Notify all concerned personnel at the end-user's facility that a test is to be conducted and instruct them as to the sequence of operation.
Disable or remove each extinguishant storage container release mechanism and selector valves,
where fitted, so that activation of the release circuit will not release extinguishant. Reconnect the release circuit with a functional device in lieu of each extinguishant storage container release mechanism.
For electrically actuated release mechanisms, these devices may include suitable lamps, flash bulbs or circuit breakers. Pneumatically actuated release mechanisms may include pressure gauges. Refer to the manufacturer's recommendations in all cases.
Check each resettable detector for proper response.
Check that polarity has been observed on all polarized alarm devices and auxiliary relays.
Check that all required end-of-line devices have been installed.
Check all supervised circuits for correct fault response.
System functional operational test
Operate the detection initiating circuit(s). All alarm functions shall occur according to the design specifications.
Operate the necessary circuit to initiate a second alarm circuit if present. Verify that all second alarm functions occur according to design specifications.
Operate the manual release device. Verify that manual release functions occur according to design specifications.
Where appropriate, operate the stop device. Verify that functions occur according to the design specifications. Confirm that visual and audible supervisory signals are received at the control panel.
Check the function of all resettable valves and activators, unless testing the valve will release extinguishant.
"One-shot" valves, such as those incorporating frangible discs, should not be tested.
Check pneumatic equipment, where fitted, for integrity to ensure proper operation.
Remote monitoring operations (if applicable)
Disconnect the primary power supply, then operate one of each type of input device while on standby power. Verify that an alarm signal is received at the remote panel after the device is operated. Reconnect the primary power supply.
Operate each type of alarm condition and verify receipt of fault condition at the remote station.
Control panel primary power source
Verify that the control panel is connected to a dedicated unswitched circuit and is labelled properly. This panel shall be readily accessible but access shall be restricted to authorized personnel only.
Test a primary power failure in accordance with the manufacturer's specification, with the system fully operated on standby power.
Completion of functional tests
When all functional tests are complete (8.2.6 to 8.2.9), reconnect each storage container so that activation of the release circuit will release the extinguishant. Return the system to its fully operational design condition. Notify the central alarm station and all concerned personnel at the end-user's facility that the fire system test is complete and that the system has been returned to full service condition by following the procedures specified in the manufacturers' specifications.
Completion certificate and documentation
The installer shall provide to the user a completion certificate, a complete set of instructions, calculations and drawings showing the system as-installed, and a statement that the system complies with all the appropriate requirements of this document, and giving details of any departure from appropriate recommendations. The certificate shall give the design concentrations and, if carried out, reports of any additional test including the door fan test.
Inspection, maintenance, testing and training
General
This clause specifies the requirements for inspection, maintenance and testing of a gaseous fire-extinguishing system and for the training of inspection and maintenance personnel.
IMPORTANT — In accordance with the European legislation, the requirements of this clause are reserved to the national body of rules and regulations of each Member State.
Inspection
General
At least annually, or more frequently as required by the authority, all systems shall be thoroughly inspected and tested for proper operation by competent personnel.
The inspection report with recommendations shall be filed with the owner.
At least every 6 months, the container contents shall be checked as follows:
Liquefied gases: for halocarbon extinguishants, if a container shows a loss in extinguishant quantity of more than 5 % or a loss in pressure (adjusted for temperature) of more than 10 %, it shall be refilled or replaced.
Non-liquefied gases: for inert gas extinguishants, pressure is an indication of extinguishant quantity. Unless otherwise specified by the authority, if an inert gas extinguishant container shows a loss in pressure (adjusted for temperature) of more than 5 %, it shall be refilled or replaced. Where container pressure gauges or weight-monitoring devices are used for this purpose, they shall be compared to a separate calibrated device at least annually.
All extinguishant removed from containers during service or maintenance procedures shall be collected and recycled, or disposed of in an environmentally sound manner, and in accordance with existing laws and regulations.
Inert gas mixtures based on those gases normally found in the earth's atmosphere are exempted from this requirement.
The date of inspection and the name of the person performing the inspection shall be recorded on a tag attached to the container.
Container
Containers shall be subjected to periodical tests as required by the relevant national standard.
Hose
All system hoses shall be examined annually for damage. If visual examination shows any defect, the hose shall be replaced.
Enclosures
At least every 12 months it shall be determined whether boundary penetration or other changes to the protected enclosure have occurred that could affect leakage and extinguishant performance. If this cannot be visually determined, it shall be positively established by repeating the test for enclosure integrity in accordance with Annex E.
Where the integrity test reveals increased leakage that would result in an inability to retain the extinguishant for the required period, remedial action shall be carried out.
Where it is established that changes to the volume of the enclosure or to the type of hazard within the enclosure, or both, have occurred, the system shall be redesigned to provide the original degree of protection.
It is recommended that the type of hazard within the enclosure and the volume it occupies, be regularly checked to ensure that the required concentration of extinguishant can be achieved and maintained.
Maintenance
General
The installer shall provide the user with instructions for use specifying the requirements for inspection and the training of personnel for personal safety measures. Information on residual risks shall be added where necessary.
The user shall carry out a programme of inspection, arrange a service schedule, and keep records of the inspections and servicing.
NOTE The continued capability for effective performance of a fire fighting system depends on fully adequate service procedures with, where possible, periodic testing.
Installers shall provide the user with a record in which inspection and service details can be entered.
User's programme of inspection
The installer shall provide the user with an inspection programme for the system and components. The programme shall include instructions on the action to be taken in respect of faults.
The user's inspection programme is intended to detect faults at an early stage to allow rectification before the system may have to operate. A suitable programme is as follows:
Weekly: Visually check the hazard and the integrity of the enclosure for changes which might reduce the efficiency of the system. Carry out a visual check that there is no obvious damage to pipework and that all operating controls and components are properly set and undamaged. Check pressure gauges and weighing devices, if fitted, for correct reading and take the appropriate action specified in the users' manual.
Monthly: Check that all personnel who may have to operate the equipment or system are properly trained and authorized to do so and, in particular, that new employees have been instructed in its use.
Service schedule
A service schedule shall include requirements for periodic inspection and test for the complete installed system, including pressurized containers, as specified in the appropriate national standards.
The schedule shall be carried out by a competent person who shall provide to the user a signed, dated report of the inspection, advising any rectification carried out or needed.
During servicing, every care and precaution shall be taken to avoid release of extinguishant. A suitable schedule is provided in Annex F.
Training
All persons who may be expected to inspect, test, maintain or operate fire-extinguishing systems shall be trained and kept adequately trained in the functions they are expected to perform.
Personnel working in an enclosure protected by a gaseous extinguishant shall receive training in the operation and use of the system, in particular regarding safety issues.Annex A
(normative)
Working documents
A.1 General
These documents shall be prepared only by persons fully experienced in the design of extinguishing systems. Deviation from these documents shall require permission from the authority.
A.2 Working documents
Working documents shall include the following items:
drawings, to an indicated scale of extinguishant distribution system, including containers, location of containers, piping and nozzles, valves and pressure-reducing devices and pipe hanger spacing;
name of owner and occupant;
location of building in which hazard is located;
location and construction of protected enclosure walls and partitions;
enclosure cross-section, full height or schematic diagram, including raised access floor and suspended ceiling;
type of extinguishant being used;
extinguishing or inerting concentration, design concentration and maximum concentration;
description of occupancies and hazards to be protected against;
specification of containers used, including capacity, storage pressure and mass including extinguishant;
description of nozzle(s) used, including inlet size, orifice port configuration, and orifice size/code and orifice size of pressure-reducing devices, if applicable;
description of pipes, valves and fittings used, including material specifications, grade and pressure rating;
equipment schedule or bill of materials for each piece of equipment or device, showing device name, manufacturer, model or part number, quantity and description;
isometric view of extinguishant distribution system, showing the length and diameter of each pipe segment and node reference numbers relating to the flow calculations;
