Post Indicator Valve
The Outdoor Sentinel

What It Is

A Post Indicator Valve (PIV) is an above-ground, manually operated gate valve mounted on a vertical steel post outdoors. It controls water flow to an underground fire service main or standpipe riser — typically on the water supply side of the building, before the backflow preventer or fire pump. The top of the post has a rectangular window labeled either OPEN or SHUT, so anyone walking by can confirm the valve's position at a glance.

PIVs exist because control valves buried in a vault or hidden in a mechanical room can be accidentally left closed after maintenance — and nothing kills a sprinkler system faster than a closed control valve. Putting the valve outside, above ground, with a visible target flag, makes it obvious.

Where It Lives

How It Works

Inside the post, a vertical operating rod connects the handwheel (or wrench socket) to a gate or butterfly valve buried in the ground. As you turn the handwheel, the rod lifts or lowers the gate. A small mechanical linkage pushes a painted target — usually yellow or red — up and down inside the window, displaying OPEN or SHUT.

Most PIVs also have a tamper switch wired back to the fire alarm panel. The instant the valve moves off its normal (open) position, the panel generates a supervisory signal. That switch is mandatory for systems serving life safety occupancies NFPA 72 §17.16.

NFPA 25 Compliance

References