7.3. Water Motor Gong
Globe’s Model WM Water Motor Alarm is a hydraulically operated outdoor alarm for use with fire protection systems. It is lightweight yet durable, and can be used in conjunction with alarm check, dry pipe, deluge, and preaction valves to sound a local alarm. This water-powered system eliminates the need for an electrical alarm and will operate even if electrical power is lost. Globe’s Model WM Water Motor Alarm features a one-gong system, which sounds an alarm outside the building.
The Water Motor Alarm is suitable for mounting to any type of rigid wall and can accommodate a wall thickness up to 16″ (406.4 mm). It is provided with a listed and approved strainer for use in the alarm line. The Gong, Gong Mount, and Water Motor Housing are fabricated from corrosion-resistant cast aluminum. The polymer drive bearings do not require lubrication. The WM utilizes a lightweight, impeller design, which can produce a very high decibel sound level. As water passes through the water motor, the impeller turns and the shaft rotates. The rotating shaft drives a striker assembly, which rings the gong, sounding a continuous alarm as long as the water flow continues.