Valve seal

Claim 1

A PRESSURE RELIEF VALVE FOR TANKS CONTAINING HIGHLY VOLATILE FLUIDS TO RELIEVE TH VAPOR PRESSURE THEREIN WHEN IT RISES ABOVE A PREDETERMINED POINT COMPRISING AN ANNULAR VALVE BODY HAVING A CHAMBER IN OPEN COMMUNICATIN WITH THE INTERIOR OF A TANK, A PORT DEFINED BY AN UPWARDLY FACING ANNULAR VALVE SEAT, SAID VALVE BODY HAVING A FLAT LOWER FACE OF SAID VALVE BODY HAVING AN ANNULAR GROOVE THEREIN OPPOSITE SAID VALVE SEAT AND OF LARGER DIAMETER THAN SAID VALVE SEAT, A WEB OF RESILIENT MATERIAL SECURED TO THE MAJOR PORTION OF SAID LOWER FACE INTERIORLY OF SAID GROOVE, SAID WEB EXTENDING ACROSS SAID GROOVE TO THE MARGINAL EDGE OF SAID LOWER FACE AND SAID MARGINS OF SAID WEB LYING AGAINST THE LOWER FACE OF SAID PLATE OUTWARDLY OF SAID GROOVE IN UNCLAMPED POSITION THEREAGAINST OUTWARDLY OF SAID GROOVE, WHEREBY THE MATING OF SAID VALVE MEMBER AND SAID VALVE SEAT OCCURS BY WHEREBY SAID VALVE OPENS WHEN THE VAPOR PRESSURE WITHVALVE OPENS WHEN THE VAPOR PRESSURE WITHIN SAID VALVE CHAMBER RISES ABOVE SAID PREDETERMINED POINT.