How does a pressure relief vent work?

A pressure relief vent (PRV) is used to ensure a room is not over pressurised if the fire suppression system activates during the test and releases its clean agent. Without a pressure relief vent, an over-pressurisation could occur which can lead to damage to the building and room structure and any equipment within the room. The PRV automatically opens its blades when a sensor circuit sees an overpressure situation.