Wet alarm valve is the water supply control valve in wet fire extinguishing system,which make the water flow in single direction and alarm under certain flow.
The working principle of wet alarm valves: relying on the on and off of valves flap caused by the up and down of water pressure from pipe network system, when in the waiting state, a little diviation of water pressure, the balance pipe will balanced the water pressure on the up and down side of valves flap, while the upside pressure bearing area is biger than downside pressure area, the valves flap will not open and wrong alarm will no happen. When fire happens, sprinkler exploded and makes the water pressure down on the side of pipe network system, the pressure difference between water supplying side and system side will open the valves flap and continuously supplying the water to the sprinkler to protect from fire.
When wet fire extinguishing system has adopted wet alarm valve,it shall be mounted in the building with environment temperature no less than 4℃ ,in case losing fire control function by freezing.
configuration of wet alarm valve shall be composed by pressure gauge, delayer, pressure switch, water motor alarm,and necessary pipe fittings and valves.
Ready condition of control ball valve between alarm entrance and delayer of wet alarm valve shall be open and locking,while trial alarm control ball valve shall be close.When trial alarm is under operation,locking device of control ball valve between alarm entrance and delayer shall be dismounted and close.Alarm test can be carried out,by opening trial alarm control ball valve.After the test has been finished,the two control ball valves shall be recovered to their original state.