Zero Velocity Valve

DVPL are manufacturer & supplier of Zero Velocity Valve for stopping reverse flow in case of failure of pumps. The valve consists of a spring loaded closing disc which is mounted on a central shaft and supported by guide rods. Valve is provided with a bye pass arrangement. Valves are generally supplied with flanged but can also be barrel ends, if so desired.
The springs are designed in such a manner that the valve remains full open when 25% of designed velocity is achieved. In case of closure of pump, disc starts closing in relation to decrease of velocity and fully closes when velocity drops near to zero. Thus upstream water column is prevented from creating water hammer wave. Bye pass arrangement keeps pressure balance on both sides of disc. It also prevents creation of vacuum in downstream side.