Preaction Systems

Preaction Systems are sprinkler systems employing automatic sprinklers attached to a piping system that contains air that might or might not be under pressure,with a supplemental detection system installed in the same areas as the sprinklers.There are two main sub-types of preaction systems: single interlock, and double interlock. The single interlock system admits water to sprinkler piping upon operation of detection devices.The double interlock system admits water to sprinkler piping upon operation of both detection devices and automatic sprinklers.

Single Interlock Preaction System

The Model DV-5 Supervised Single Interlock Preaction System with Electric Actuation utilizes automatic sprinklers and a supplemental detection system. The supplemental detection system is typically comprised of 24 VDC heat detectors, smoke detectors,manual pull stations, etc. Actuation of the detection system automatically operates (releases) the Model DV-5 Deluge Valve, allowing water to flow into the sprinkler piping system and to be discharged from any sprinklers that may be open.

    Double Interlock Preaction System

    The Model DV-5 Double Interlock Preaction System with Electric/Pneumatic Actuation utilizes a Model DV-5 Deluge Valve and a Riser Check Valve. The Riser Check Valve (that does not require the use of priming water) isolates the Deluge Valve from the system air pressure. The releasing trim for the Deluge Valve utilizes a Solenoid Valve and a Dry Pilot Actuator in a series configuration. The system air pressure holds the Dry Plot Actuator closed, whereas the Solenoid Valve remains closed until it is electrically energized by a Deluge Valve Releasing Panel (automatic control unit). The Releasing Panel is operated by either a fire detection device or manual electric pull station.