The 3" VXR Dry Pipe Valve is an externally resettable, latching, differential valve used to separate the water supply from the dry pipe sprinkler system. The valve includes a clapper assembly with a differential air-to-water seat design. The clapper provides a positive mechanical seal for the air/nitrogen pressure in the dry pipe system. The differential design allows an air/nitrogen supply of moderate pressure to control a higher water supply pressure. When the air/nitrogen pressure in the dry pipe system is lowered sufficiently to overcome the pressure differential, the valve opens allowing water to enter the dry pipe system. The clapper is reset using a convenient push rod located on the bottom of the valve body.

The valve is also designed to operate a water motor alarm and/or an electric pressure alarm switch. The Viking Model D-2 Accelerator can be used to speed the operation of the valve on large capacity systems or where faster action is required.