What type of fire sprinkler system is activated by heat over a specific range?

A pre-action system is a type of fire sprinkler system that requires a two-step activation process, typically involving both heat and an additional initiation, often triggered by smoke detection. This system utilizes both a detection element and the sprinklers themselves to effectively manage the risk of water damage while still being responsive to fire.

In this system, when heat reaches a predetermined temperature range, the sprinkler heads do not immediately release water; rather, they require activation from a fire detection system. Once the heat is detected, the valve opens, allowing water to fill the pipes. If a fire continues to grow and the heat level peaks, the sprinkler heads will activate, releasing water only in the areas where the fire has occurred. This helps mitigate water damage in areas that are not affected by fire, since water is only released when necessary, thus offering a controlled response.

Other systems, such as wet pipe and dry pipe systems, do not have this two-step activation or reliance on both heat and detection; they function differently in terms of immediate water release during a fire event. A deluge system is also distinct in that it opens multiple sprinkler heads at once, but it is not specifically dependent on heat detection in the same manner. Understanding the mechanics of a pre-action system is key