In a deluge system, the sprinkler heads are always "open" (they have no glass bulb or fusible link). The system is connected to a deluge valve controlled by a fire detection system. When a fire is detected, the valve opens, and water sprays from all heads simultaneously.

categorizes sprinkler systems into four primary types, each suited for different environments and risk levels:

Low combustibility and low quantity of contents (e.g., offices, schools).