Push-pull automatic sealing system for valves

Claim 1

IN AN AUTOMATIC PLASTIC-SEALED VALVE INCLUDING A HOUSING HAVING A FLOWWAY THERETHROUGH, A CLOSURE MEMBER FOR THE FLOWWAY MOVABLE BETWEEN POSITIONS OPENING AND CLOSING THE FLOWWAY, A SEAT IN THE FLOWWAY ENGAGEABLE BY THE CLOSURE MEMBER, A SEALING GROOVE SYSTEM DISPOSED ABOUT THE FLOWWAY BETWEEN THE SEAT AND THE CLOSURE MEMBER, A SEALANT RESERVOIR IN THE HOUSING HAVING PASSAGE COMMUNICATION AT SPACED POINTS RESPECTIVELY WITH THE INTERIOR OF SAID HOUSING AND WITH SAID SEALING GROOVE SYSTEM, A BARRIER MEMBER SLIDABLE IN SAID RESERVOIR BETWEEN SAID SPACED POINTS OPERABLE IN RESPONSE TO LINE PRESSURE ACROSS SAID VALVE WHEN THE CLOSURE MEMBER IS IN THE FLOWWAY-CLOSING POSITION TO DISPLACE SEALANT FROM SAID RESERVOIR INTO SAID SEALING GROOVE SYSTEM, A PRESSURE BOOSTER CHAMBER IN SAID HOUSING, A PISTON SLIDABLE IN SAID BOOSTER CHAMBER, MEANS OPERATIVELY COUPLING SAID PISTON TO SAID BARRIER MEMBER FOR MOVEMENT THEREWITH IN THE SEALANT DISPLACING DIRECTION, AND PASSAGE MEANS COMMUNICATING THE LINE PRESSURE TO SAID BOOSTER CHAMBER ARRANGED TO APPLY SAID LINE PRESSURE TO SAID PISTON IN A DIRECTION TO SUPPLEMENT THE SEALANT-DISPLACING FORCE OF SAID BARRIER MEMBER.