Abstract: The present invention relates to fluid control valves. The invention provides an improved diaphragm useful for a large hydraulically-operated valve or pressure regulating valve of the type used in pipelines to transport water, oil, gas, acids, alkalis and other fluids. The diaphragm being provided with an upper face arranged to be exposed to a control hydraulic pressure and a lower face arranged to selectively seal and open a passage between a valve inlet and a valve outlet, ribs on said upper face urging the diaphragm towards a sealing position. The diaphragm being characterized by the addition of an elastomer ring element disposed adjacent to the upper face and adjacent to the largest diameter of the diaphragm exposed inside a valve to which it may be assembled, an upper face of the flexible ring element being in pressure contact with a portion of the rigid body of the valve.

Abstract: A spring diaphragm for use in automatic hydraulic control valves of the type having a valve body having an inlet chamber, and an outlet chamber and a spring diaphragm interposed between the inlet and outlet chambers, which spring diaphragm, as a result of hydraulic pressure, is automatically moveable between an open and closed position, in which the diaphragm allows and prevents, respectively, communication between the inlet and outlet chambers, includes a two-part diaphragm element including a first lower part and second upper part generally spaced apart from one another, the first lower part being in the form of a flexible elastic disc which performs the function of a hermetic seal between the inlet and outlet chambers when the spring diaphragm is in the closed position and the second upper part being connected to the first part and being in the form of a resilient disc which performs the function of a spring to normally bias the spring diaphragm from the open to the closed position.