7.2. Alarm Check Valve
The Globe 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.
Incorporating electrical pressure switches allow the use of supplemental alarms, annunciators etc.
A unique feature found on the Globe 3″, 4″, 6″ and 150mm Alarm Valves is the clapper being hinged to the handhole cover for extreme ease of removal for inspection and service.
Globe Model H-1, H-2 and H-3 Alarm Check Valves may be installed in both vertical and horizontal positions and trim can be provided for both variable and constant water supply pressures in either of these positions.
The body of the Alarm Check Valve is constructed of high tensile strength cast iron having considerable ductility to reduce damage in field handling. All interior operating parts are machined from highly corrosive-resistant alloys, each having high strength and good wear resistance. Rubber parts are of selective materials which have good abrasive resistance and long life expectancy in terms of resiliency.