Patent ID: 7059578

Claim:
An elastomer diaphragm for use in a hydraulically-operated valve, said diaphragm being provided with an upper face arranged to be exposed to a control hydraulic pressure and a lower face arranged to seal and open a passage between a valve inlet and a valve outlet, ribs on said upper face urging said diaphragm towards a sealing position, said diaphragm being characterized by the addition of an elastomer ring element disposed adjacent to said 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 said flexible ring element being in pressure contact with a portion of the rigid body of said valve, said elastomer ring element further urging said diaphragm towards its lower position and allowing closure of said valve without use of a metallic compression spring, wherein said urging of said diaphragm towards its lower position by said elastomer ring is enabled also when the hydraulic pressure above and below said diaphragm are equal.