This valve is pneumatically actuated and provides pressure control. This valve is used where a constant downstream pressure and a controlled smooth opening and closing of the deluge water supply is called for. The valve's adjustable restrictors can be set to provide the opening- and closing speed desired, to prevent the damaging effects of reaction forces and water hammer. The valve is fitted with an external pneumatic actuator to facilitate activation from e.g. pilot line air pressure drop. The actuator if fitted with a latch that locks the actuator and deluge valve open when activated, thus requireing manual re-setting to close.