Check valve

Claim 1

A VALVE COMPRISING A BODY, A CONICAL VALVE SEAT ON SAID BODY, SAID VALVE SEAT FLARING REARWARDLY FROM A REDUCED DIAMETER PORTION AT THE FORWARD END TO AN ENLARGED DIAMETER PORTION, AN AXIALLY MOVABLE POPPET IN SAID BODY COAXIAL WITH SAID VALVE SEAT, A RADIAL FACE AND AN ANNULAR CONICAL FACE ON SAID POPPET, SAID RADIAL POPPET FACE HAVING A DIAMETER INTERMEDIATE THOSE OF THE REDUCED AND ENLARGED PORTIONS OF SAID VALVE SEAT, SAID CONICAL POPPET FACE HAVING AN APEX ANGLE LESS THAN THAT OF SAID VALVE SEAT, A SEAL RETAINER HAVING A RADIAL FACE OPPOSED TO SAID FIRST-NAMED RADIAL FACE SECURED TO SAID POPPET, AND A CENTRALLY PERFORATED ANNULAR SEALING MEMBER OF RESILIENT SHEET MATERIAL SECURED BETWEEN SAID POPPET AND SAID RETAINER, SAID SEALING MEMBER EXTENDING ACROSS THE RADIAL FACE OF SAID POPPET TO SAID CONICAL POPPET FACE, SAID SEALING MEMBER HAVING A REARWARDLY EXTENDING CONICAL LIP PORTION ADAPTED TO SEALINGLY ENGAGEWITH SAID CONICAL VALVE SEAT, THE REARWARD END OF SAID LIP BEING SPACED AWAY FROM SAID CONICAL POPPET FACE AND IN CONTACT WITH SAID CONICAL VALVE SEAT WHEN SAID POPPET IS IN THE CLOSED POSITION WITH THE FORWARD END OF SAID CONICAL LIP COMPRESSED BETWEEN SAID POPPET AND SAID VALVE SEAT WITH SAID POPPED AND SAID RETAINER BEING SPACED AWAY FROM SAID VALVE SEAT AT ALL POINTS.