Shandong dingliang fire control technology co., LTD., a fire extinguisher manufacturer in shandong, explains the working principle of wet alarm valve for you:

System composition: the wet sprinkler system consists of a terminal water test device, a closed sprinkler, a pressure switch, a pipe system, a water flow indicator, a wet alarm valve, an alarm device and a water supply facility. 

The working principle of wet alarm valve: when a fire occurs, the high temperature airflow makes the heat sensitive element of the closed nozzle move and the nozzle opens to spray water. The water in the pipe network changes from static to flowing, and the water flow indicator moves under the action of water flow. The electrical signal is output to the alarm controller, and the alarm controller indicates that a certain area has been spraying water. Continuous water spraying causes the valve pressure of the wet alarm valve to be lower than the pressure before the valve. Under this pressure difference, the alarm valve disc in the original closed state will open automatically. The pressure water flows to the main pipe and the distribution pipe through the wet alarm valve. Meanwhile, water flows into the delay device through the alarm pipeline interface. After the delay confirmation, water flows into the subsequent pipeline. According to the signal of the pressure switch, the controller can automatically start the fire pump to pressurize the water supply to the pipe network to achieve the purpose of continuous automatic water spraying.

The wet alarm valve is the water supply control valve in the wet fire extinguishing system. It allows water to flow in one direction and alarm at a certain amount of flow. The working principle of the wet alarm valve is to reduce or increase the opening and closing valve disc by the side water pressure of the pipe network system. When the water pressure on the side of the pipe network system drops due to blasting in the event of fire, the pressure difference between the water supply side and the system side will open the valve disc to the open sprinkler head for continuous water supply to extinguish the fire. Using wet alarm valve of the wet fire extinguishing system, must be installed in buildings in the environment temperature is not lower than 4 ℃, lest cause ice lost fire control function.

The standard features of wet alarm valves include: pressure gauges, delayers, pressure switches, hydraulic alarms, and necessary pipe fittings and valves. The control ball valve between the wet alarm valve alarm port and the delay device must be fully open and locked, while the test alarm control ball valve must be closed. When a test alarm is needed: remove the lock device between the alarm port and the delay device to control the ball valve and close it. The alarm test can be carried out by opening the test alarm control ball valve. The two control ball valves will be restored to the original state immediately after the test.