Pilot operated valve

Claim 1

A PILOT OPERATED VALVE COMPRISING: A VALVE BODY PROVIDED WITH A MAIN PASSAGEWAY HAVING AN INLET END AND AN OUTLET END, A PRESSURE RESPONSIVE MEMBER HAVING EXPANSIBLE CHAMBER MEANS RESPONSIVE TO PRESSURE CONDITIONS IN SAID INLET AND OUTLET ENDS FOR ACTUATING SAID MEMBER TO OPEN AND CLOSE SAID MAIN PASSAGEWAY, A FIRST PILOT PASSAGEWAY FORMED IN SAID BODY AND COMMUNICATING BETWEEN SAID INLET END AND SAID CHAMBER, A SECOND PILOT PASSAGEWAY FORMED IN SAID BODY COMMUNICATING BETWEEN SAID CHAMBER AND SAID OUTLET END, A PORTION OF EACH OF SAID PILOT PASSAGEWAYS BEING DEFINED BY A SURFACE ON SAID VALVE BODY AND A GASKET OVERLYING SAID SURFACE, A PRESSURE PLATE ON SAID GASKET FOR URGING THE LATTER INTO SEALING ENGAGEMENT WITH SAID SURFACE, GROOVE MEANS FORMED ON THE FACE OF SAID PRESSURE PLATE THAT IS IN ENGAGEMENT WITH SAID GASKET TO PERMIT SAID GASKET TO DEFLECT AWAY FROM SAID SURFACE UNDER PRESSURE OF THE FLUID IN THE PILOT PASSAGEWAYS AND INTO SAID GROOVE MEANS TO THEREBY ESTABLISH SAID PILOT PASSAGEWAYS, AND A PILOT VALVE ELEMENT ADAPTED TO URGE SAID GASKET INTO ENGAGEMENT WITH SAID SURFACE FOR PREVENTING FLOW THROUGH SAID SECOND PILOT PASSAGEWAYS TO APPLY THE PRESSURE OF FLUID FROM SAID INLET END TO SAID CHAMBER THEREBY ACTUATING SAID MEMBER TO A POSITION CLOSING SAID PASSAGEWAY.