Supervisory Switch for Outside Screw & Yoke (OS & Y) Valve

This supervisory switch for an outside screw and yoke (OS & Y) valve is used to detect unauthorized operation of a main control valve in a sprinkler or standpipe system. It transmits an electrical impulse to activate an audible or visual alarm. It is intended for use with an OS & Y gate valve from 0.5” (1.2 cm) through 12” (30.4 cm) in size and has a red tamperproof cover with a J-bolt mounting.