Vent valve with pilot and injection control

Claim 1

PRESSURE RELIEF APPARATUS OF THE AUTOMATIC PILOT CONTROLLED MAIN RELIEF VALVE TYPE, MAIN AND SUPPLEMENTAL CONDUITS HAVING OPEN TERMINAL PORTIONS SPACED APART FOR COMMUNICATION AT SPACED POINTS WITH A CONTAINER TO BE REGULATED, A VALVE SEAT COMMUNICATING WITH THE MAIN CONDUIT, A DIAPHRAGM, A MAIN VALVE CARRIED BY THE DIAPHRAGM AND ADAPTED TO CLOSE SAID SEAT EXTERNALLY, THE DIAPHRAGM BEING SEALED TO A MAIN VALVE HOUSING TO FORM WITH IT AN OPERATING CHAMBER AND BEING EXPOSED TO THE ATMOSPHERE IN AREAS SURROUNDING THE MAIN VALVE; A PILOT VALVE SEAT, A PILOT VALVE CAP OF LIGHT CONSTRUCTION ADAPTED TO CLOSE SAID SEAT BY GRAVITY ALONE AXCEPT WHEN A PREDETERMINED PRESSURE RAISES IT FROM THE SEAT, A PRE-INJECTION NOZZLE COMMUNICATING WITH THE SUPPLEMENTAL CONDUIT AND DIRECTED TO DISCHARGE THROUGH SAID SEAT TOWARD THE CAP, TO BLOW GAS AT HIGH SPEED THROUGH THE PILOT SEAT WHEN PRESSURE IS ABOVE SAID PRE-DETERMINED PRESSURE, SAID CAP BEING RAISED SOLELY BY GAS WHICH HAS PASSED THROUGH SAID NOZZLE AND HAVING A DOWNWARDLY EXTENDING FLANGE SURROUNDING THE PILOT SEAT TO ENSURE SUBSTANTIAL LIFT AT LOW PRESSURE, THE FLOW AREA BEYOND THE SEAT BEING OTHERWISE SUBSTANTIALLY UNRESTRICTED, AND AN INJECTION RING SPACED AROUND THE NOZZLE OUTLET TO FORM AN INJECTION OPENING AND THROUGH WHICH GAS FLOWS FROM SAID NOZZLE TO AND THROUGH SAID PILOT SEAT, SAID INJECTION OPENING COMMUNICATING WITH THE OPERATING CHAMBER WHEREBY GAS IS SUCKED BY INJECTION ACTION AT SAID INJECTION RING FROM SAID OPERATING CHAMBER WHEN SAID PILOT VALVE IS OPEN AND IS BLOWN INTO SAID OPERATING CHAMBER THROUGH SAID INJECTION OPENING WHEN THE PILOT VALVE IS CLOSED, THE DIAPHRAGM BEING SUBSTANTIALLY LARGER IN DIAMETER THAN THE VALVE SEAT AND THE VALVE AND PARTS MOVING WITH IT BEING OF LIGHT CONSTRUCTION AND SAID VALVE BEING ACTUATED BY GRAVITY AND GAS PRESSURE ALONE.