A Deluge Valve is a quick-opening, hydraulic control valve. Unlike standard closed-head sprinklers (which release water locally where a glass bulb bursts), a deluge system uses open sprinkler heads (no glass bulbs). The deluge valve keeps the line empty of water until a separate fire detection system (like smoke/heat detectors) triggers the valve. Once opened, water floods the entire system, discharging from *all* sprinkler heads simultaneously. It is used in high-hazard zones like chemical refineries to suppress flash fires.