Sprinklers, Valves & Pipework

Sprinklers

A sprinkler head opens on its own when the heat around it reaches its temperature rating. Only the heads near the fire open, so water goes where it is needed. A pendent sprinkler hangs down from pipes above a false ceiling. An upright sprinkler points up from exposed pipes, as in warehouses, car parks and factory floors. Our guide Fire Sprinkler System: How It Works and What You Need explains the whole system.

Control valves

• Alarm check valve: the main valve of a wet sprinkler system. It lets water flow to the sprinklers and raises the alarm when they open.
• Deluge valve: opens all the open nozzles at once when the detection system signals. Used for transformers, fuel areas and other high-hazard risks.
• Zone control valve: controls and monitors the sprinklers on one floor or zone, usually with a water flow switch that tells the fire alarm panel which zone is flowing.
• OS and Y gate valve: an isolating valve whose rising stem shows at a glance whether it is open or closed.

Line valves and accessories

A non-return valve stops water flowing backwards, for example on each pump outlet. A pressure reducing valve brings the pressure down on the lower floors of a tall building. A pressure relief valve protects the pipes from too much pressure. An air release valve lets trapped air out of high points. A Y-strainer catches dirt before it reaches the valves. A flexible joint takes up vibration and small movement, often at pump connections. A compound pressure gauge reads the pump suction, and a flow meter measures the pump's output during a test. An anti-vortex plate sits at a tank's suction outlet, and a waste cone takes the drain water from a test valve.

Hydrant points and pipe

A landing valve is the outlet on each floor where fire fighters connect their hose. A hose cabinet keeps the hose, nozzle and valve together and ready. The whole network is built with MS pipe and MS fittings.

Common questions