The HVWSS is designed for a minimum spray density of 10.2 lpm per square meter of surface area. The design & installation of water spray system shall also conform to the requirement of TAC.
The headers shall remain charged with water at the desired pressure. Whenever the water spray system operates, the discharge of water from the header shall result in a drop in pressure, which shall cause firefighting system pumps to come into operation.
The automatic HVWSS for transformer shall work on wet pilot detection system. A pipe network fitted with quartzoid bulb detectors shall be provided around transformer. This pipe network shall be kept pressurized by water tapped from the upstream side of a deluge valve. The downstream of deluge valve is kept dry and shall be connected to a pipe network having strategically located spray nozzles around transformers. In case of fire, the quartzoid bulbs shall break, there by releasing the pressure in detector network. This shall hydraulically open the deluge valve thus allowing water to be sprayed on to the transformer through projector nozzles / sprinklers in the form of a solid conical emulsifying spray.
Pressure gauges shall be provided in the spray pipe and the detector network pipe respectively to indicate the available pressure.
Deluge valve shall be provided with two pressure switches for following remote annunciation in the fire alarm panel located in the control room.
- Detector network operated
- Deluge valve open
The trim of the deluge valve shall have manual emergency release as well as electrical actuation through solenoid-operated valve and push button. A local control panel shall be provided for deluge valve for local actuation. It shall be possible to remotely actuate the deluge valve from the fire alarm panel located in the Control room.