What is the function of a post indicator valve (PIV) in a sprinkler system?

The function of a post indicator valve (PIV) in a sprinkler system is primarily to provide a visual indication of the valve status. This allows firefighters and personnel to quickly assess whether the valve that controls water flow to the sprinkler system is open or closed. The visual indicator, typically a visible flag or a marking on the valve, enhances operational efficiency during an emergency response, ensuring that water can be supplied immediately to the sprinkler system if needed. Having this clear indication helps in preventing accidental shutdown of the system and ensures that the sprinkler system is operational when a fire occurs.

While other options such as automatically extinguishing fires or regulating water temperatures might seem related to fire suppression, they are not functions of the PIV. Similarly, measuring water pressure is important in fire systems but is handled by different components, not by a post indicator valve.