Alarm Check Valves
When there is a steady flow of water into the sprinkler system due to a sprinkler operation, the Waterway Clapper opens. Water is then permitted to flow into the centrally located groove in the Seat Ring and out through the alarm port towards the Restriction Assembly. When the flow through the Inlet Restriction of the Restriction Assembly exceeds the flow through the Outlet Restriction, the Retard Chamber (where provided for systems with variable pressure)
Subsequently, the Water Motor Alarm and/or the pressure alarm switch will be actuated. The alarms will continue
to be actuated as long as the Waterway Clapper remains open. Water in the alarm lines will automatically drain out through the 1/8 inch (3,2 mm) Drain Orifice in the Restriction Assembly when the Waterway Clapper closes (due to a stop in the flow of water into the sprinkler system).