Automatic plastic-sealed valve with two-stage sealing

Claim 1

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 FULL-PORT SEALANT GROOVE DISPOSED ABOUT THE FLOWWAY BETWEEN THE SEAT AND THE CLOSURE MEMBER, A SEALANT RESERVOIR IN THE HOUSING HAVING ONE END IN COMMUNICATION WITH THE INTERIOR OF THE HOUSING, PASSAGE MEANS ARRANGED TO CONNECT THE OTHER END OF THE RESERVOIR WITH SAID SEALANT GROOVE IN THE FLOWWAY-CLOSING POSITION OF SAID CLOSURE MEMBER, UPPER AND LOWER SPACE APART BARRIER MEMBERS SLIDABLY DISPOSED IN SAID RESERVOIR BETWEEN THE ENDS THEREOF, MEANS BIADING SAID BARRIER MEMBERS TOWARD EACH OTHER, MEANS LIMITING MOVEMENT OF THE LOWER BARRIER MEMBER TOWARD THE UPPER BARRIER MEMBER, A PASSAGEWAY THROUGH THE LOWER BARRIER MEMBER COMMUNICATING THE RESERVOIR PORTION BETWEEN THE BARRIER MEMBERS WITH THE RESERVOIR PORTION BELOW THE LOWER BARRIER MEMBER, AND MEANS FOR INTRODUCING SEALANT INTO BOTH SAID RESERVOIR PORTIONS, SAID LOWER BARRIER MEMBER HAVING AT LEAST A PORTION OF ITS LOWER FACE SUBJECT TO DOWNSTREAM PRESSURE WHEREBY THE PRODUCT OF THE PRESSURE ACTING ON THE AREA OF ITS UPPER FACE IS GREATER THAN THE PRODUCT OF THE PRESSURE ACTING ON THE AREA OF SAID LOWER FACE.