The AG Sprinkler Model H-1, H-2 and H-3 Alarm Check Valves are used in wet pipe fire sprinkler systems. They primarily serve a dual purpose in that they prevent a reverse flow of water through their bodies (non-return) and also provide for the use of a hydraulic fire alarm which is not dependent upon an electrical power supply for its operation. Through the use of a hydraulic retard chamber a time delay is provided to eliminate potential false alarms caused by fluctuating water supply pressures. Where constant pressure water supplies are used the retard chamber (time delay) is not necessary. By incorporating the use of electrical pressure switches, other supplemental alarms, annunciators etc. may also be used.
