Rupture disk controlled hydraulically actuated valve assembly

Abstract

A pressure responsive valve assembly is disclosed as having a frangible burst disk that largely controls actuation of the valve. The valve assembly includes a housing having an inlet and an outlet and a valve seat therein. An actuating unit includes a collapsible fluid chamber and a moveable pressure responsive valve member. The valve member is engageable with the valve seat, positioned to experience the pressure conditions at the inlet, and operably coupled with the mechanism to cause collapsing of the fluid chamber when the valve member moves relative to the valve seat to establish or close communication between the inlet and outlet. The rupture disk normally blocks fluid flow from the chamber and thereby prevents collapsing of the chamber and corresponding movement of the valve member until the valve member experiences a predetermined maximum pressure at the inlet. When the overpressure is sensed at the inlet, the valve member moves relative to the valve seat and causes the disk to rupture and the fluid chamber to collapse. The valve assembly is particularly useful in bypass arrangements, wherein the valve assembly is arranged to relieve pressure in a primary line caused by failure of a primary valve. A new rupture disk assembly for use in the valve assembly is also disclosed.