A pump discharge valve is necessarily a Butterfly valve fitted on the discharge side of the pump which acts as a non return valve and as an isolation valve.

Its main function is to prevent the reverse flow of water in the event of pump shut down.

Pump discharge valve for the large pumping schemes is a cost effective solution to the option of utilizing an isolating valve and a non-return valve on the pump outlet. Owing to its Butterfly type of construction, the pump discharge valve has high flow capacity and low head loss (i.e. pressure drop) which would reduce the pumping energy substantially on a continuous basis. Hailed as a major breakthrough in modern pumping design, the Butterfly type pump discharge valve has made inroads into lift irrigation projects, which are the largest consumer of centrifugal pumps.