Closer examination reveals the presence of supervisory switches on the backflow preventer’s outside stem and yoke (OS&Y) valves, a water pressure gauge measuring about 150 pounds per square inch (psi) (10.3 bar), a main drain assembly, and a water metering assembly on the backflow preventer. The OS&Y valves are open—as evidenced by the visible...
2012 Photo of the Week #34 (Fire Protection)
