Oval shaped valve with balancing pilot piston

摘要

A valve is disclosed wherein a valve member is disposed in the chamber of a valve body in such a way that the valve member is axially displaceable so as to open or close the valve, and a pilot cylinder is provided in order to encounter the unbalanced force acting on the valve member due to the difference in pressure between the primary and secondary sides of the valve. When the valve is wide opened, the liquid flows at the same speed, and the pressure loss is reduced to such an extent as almost equal to the pressure loss of a gate valve in wide opened position.