Description

The Model DDX deluge valve is a hydraulic piston operated, mechanical type deluge valve. The valve is designed for use as a primary control valve in deluge, preaction or special types of fire protection systems. Following operation, the valve is able to be reset externally.

When the side chamber of the Reliable Model DDX Deluge Valve is pressurized, hydraulic supply pressure acts on the piston and pushrod assembly and simultaneously on the underside of the clapper. The resultant force of the supply pressure acting on the piston/pushrod is multiplied by the mechanical advantage of the lever and is more than sufficient to hold the clapper closed against normal supply pressure surges.

When a releasing device vents the pushrod chamber to atmosphere through the chamber’s outlet, the pushrod chamber pressure falls instantaneously. When the hydraulic pressure in the pushrod chamber approaches approximately one-third of the supply pressure, the upward force of the supply pressure acting beneath the clapper overcomes the lever-applied force thereby opening the clapper. Once the clapper has opened, the lever acts as a latch, preventing the clapper from returning to the closed position. Water from the supply flows through the Model DDX Deluge Valve into the system piping. Water also flows through the valve’s alarm outlet to any attached alarm devices.