AS 2118.3:2010 – Automatic fire sprinkler systems Part 3: Deluge systems
AS 2118.3:2010 – Automatic fire sprinkler systems Part 3: Deluge systems.
Hydraulic losses through valves used, and K factors of sprinklers used, shall be those published by the manufacturers of the valves and sprinklers, under the terms of their approval.
2.8 DETECTION SYSTEMS
Detectors installed to activate a deluge system shall be suitable for the environment, with regard to their electrical classification and materials of manufacture, and shall be installed and located in accordance with the requirements of AS 1670 series.
Care shall be exercised in the selection of detection systems, due to the potential problems of spurious operation.
Where sprinklers are used as detectors and installed on pressurized inert gas, air or liquid lines, they shall be of the fast response type in accordance with AS 4 11 8. 1 . 1.
When used as detectors, these sprinklers shall be spaced in accordance with the light hazard requirements of AS 2118.1. MJCs shall be spaced in accordance with the ordinary hazard requirements of AS 2118.1.
2.9 DELUGE VALVES
Deluge valves controlling water to a deluge system shall be located as close as practicable to the system they are controlling, ensuring that the transit time to the most remote zone is no more than 30 s. The deluge valves shall be protected in the following manner:
(a) Valves located outside the building, fire resistant construction (FRC’) wall Deluge control assemblies located outside of a building shall be considered protected provided the external wall has a FRL of 60/60/60, as shown in Figure 2.9.1.
(h) Valves located outside the buildmg. non—FR( wall Deluge control assemblies located outside of a building having an external wall construction less than 60/60/60 shall be situated at a minimum distance of 10 m from the wall, as shown in Figure 2.9.1.
(c) Valves located inside the building, outside protected area Deluge control assemblies located inside a building shall be situated at a minimum distance of 10 ni from the perimeter of the protected area, as shown in Figure 2.9. 1.
NOTE: Location of the valves close to the deluge protected area is necessary to hold to a minimum the time taken for the water to reach the fire area after the deluge valve has opened. To achieve minimum transit time, burst discs may be used downstream of the deluge valve (where transit times are critical).
2.9.2 Response time
Where sprinklers are used as detectors, the detector piping layout sizing shall be designed so that the response time of the deluge valve is no more than 20 s after the operation of the hydraulically/pneumatically most remote sprinkler detector and manual operation point.
2.9.3 Manual operation
The system shall be fitted with a discrete method of manual operation. Manual operation points shall be located at each deluge valve and at a strategic point, or points, within each zone.
2.9.4 Deluge valve trim
Where sprinklers are used as detectors on either water or air-charged lines, the deluge valve trim arrangement shall be as shown in Figure 2.9.4 (a) and Figure 2.9.4 (b) respectively, or in accordance with the requirements of a listed system.
Where water charged lines are used in the detection system, the height of all parts of that system shall be checked to ensure that the head of water on the deluge valve actuating mechanism will not prevent it from operating.
2.9.5 Remote test valve
On piped detection systems, a remote test valve shall be located at the most remote end of air or gas charged systems or at the highest detector on water charged systems, to simulate the operation of a detector sprinkler.
An air gap shall be provided immediately downstream of the test valve to act as a vacuum breaker preventing a syphoning effect which could artificially reduce test operating times.
2.10 MULTIPLE JET CONTROLS (MJCs)
Deluge systems using MJCs shall incorporate an alarm valve conforming to the requirements of AS 211 8.1.
Deluge systems using MJCs as the controlling mechanism shall, where practicable, have a manually operated bypass valve to pass water from the supply to the open sprinklers, as shown in Figure 2.10. The system shall be arranged so that, in the event of operation of any one MJC or bypass, sufficient water will flow to satisfy the whole system or zone.
The removal, treatment and disposal of deluge system discharge shall take into consideration the requirements of the relevant authority.
NOTE: Facilities may be required for the retention, safe removal, treatment and disposal of the anticipated discharge from the deluge system in accordance with the requirements of the EPA and local authorities.