An anti-pressure surge device mounted in or on a closure member (1) of a check valve to eliminate overpressure and reduce shock waves in a pipeline when the check valve closes. The anti-pressure surge device comprises a fast acting flow relieving valve having a flow path sufficient in the open position to relieve th...

A dual plate check valve comprises a substantially cylindrical valve body 10 provided with a diametrical cross-member 14 thereby defining a pair of substantially D-shaped apertures, and two substantially D-shaped plates 18, pivotally connected by a hinge means 20 parallel to said cross-member 14, and pivotable betwe...