Alarm Valves are designed to initiate an alarm through a water motor gong bell and/or pressure switch during a sustained flow of water via a wet pipe (such as the flow required by an open fire sprinkler). HD Alarm Valves are UL Listed and FM Approved. Alarm Valves are available with trims consisting of retarding chamber and water motor alarm gong bell. Please refer to product catalogues for approval information, technical specifications, structure, operating principle, and ordering information on Alarm Valves. Without further ado, install the alarm valve in your fire fighting sprinkler system.