What type of fire suppression system uses a two-phase response?

A pre-action fire suppression system operates using a two-phase response, which is critical for providing an effective means of fire control in areas where protecting sensitive equipment and minimizing water damage is a priority.

In the first phase, the detection system, typically consisting of heat and smoke detectors, activates upon detecting a fire. This triggers the pre-action valve to open, allowing water to fill the pipes of the system but does not yet release water onto the protected area or contents. This controlled response ensures that there is no water discharged during a false alarm, protecting delicate electronics or valuable assets.

The second phase occurs when a fire is confirmed, and, once the fire suppression system continues to detect conditions indicative of a fire—such as smoke or heat—the sprinklers or water discharge nozzles are then activated. This two-step approach allows for a delay in water discharge until fire conditions are verified.

This system effectively combines the aspects of both detection and suppression, offering enhanced safety by minimizing the risk of water damage while still being ready to combat an actual fire quickly and efficiently.