Casing Relief Valve Fire Pumps

A casing relief valve for a fire pump is a diaphragm type of relief valve that is spring loaded with a direct-acting mechanism. There is no specific or ideal position for its installation, meaning that it can be installed in any position. In addition, it can open and close within very close pressure limits. If you’re looking to convert it to an angle pattern flow path, simply remove the bottom plug and install it in the inlet.  Casing relief valves are made by a wide range of manufacturers including Cla-Val, Kunkle, Watson McDaniel, Watts, Singer and more. Popular models of casing relief valves are Cla-Val 55L60, Watson McDaniel 10691 and Kunkle Model 20.

What is the Casing Relief Valve on a Fire Pump Used For?

The pump casing (circulation) relief valve meets a vital purpose. It prevents automatically controlled pumps from overheating, when they’re being operated at shut-off or no discharge. However the valve is not needed for those engine driven pumps for which the water for engine cooling is taken from the pump discharge.

The casing relief valve is situated at the casing discharge. In terms of its setting, it should be set, in the field. Or more precisely it should be set at the point just below the lowest expected suction pressure plus the shutoff pressure of the unit. Also it should be piped to drain.

As a leading distributor of backflow parts in the country, American Backflow offers a diverse array of backflow parts from highly reputable manufacturing companies. Our partnership with the leading original equipment manufacturers helps us meet our clients’ varied requirements. Some of the manufacturers we represent are Ames, Apollo Conbraco, Febco, Watts and Wilkins.

Our full line of inventory is comprised of repair parts, specialty tools, complete assemblies, accessories, testing equipment, shutoff valves, ACV, fire protection equipment, OCV control valves, and enclosures and cages.