Vapor pressure control in liquefied gas dispensing

Claim 1

A PACKPRESSURE REGULATOR VALVE IN A HIGH PRESSURE LINE CARRYING A LIQUEFIED GAS, COMPRISING: (1) A VALVE BODY HAVING A PASSAGEWAY THERETHRU FOR FLUID AND A VALVE SEAT AND VALVE HEAD ADAPTED TO OPEN AND CLOSE SAID PASSAGEWAY; (2) A STEM CONNECTED WITH THE VALVE HEAD OF (1) HAVING A PISTON ON ITS END REMOTE FROM SAID HEAD AND A CYLINDER SLIDABLY ENCLOSING SAID PISTON TO FORM A FIRST COMPARTMENT ON THE SIDE ADJACENT SAID HEAD AND A SECOND COMPARTMENT ON THE SIDE REMOTE FROM SAID HEAD; (3) A PILOT VALVE REGULATOR FOR SAID BACKPRESSURE REGULATOR COMPRISING A VALVE HOUSING HAVING A DIAPHRAGM ACROSS AN INTERMEDIATE SECTION THEREOF FORMING A VAPOR PRESSURE COMPARTMENT AND A VALVE COMPARTMENT THEREIN; (4) A FLUID PASSAGEWAY THRU THE VALVE COMPARTMENT OF (3) HAVING A VALVE SEAT THEREIN, A VALVE HEAD SEATABLE ON SAID SEAT FROM THE DIAPHRAGM-SIDE THEREOF, AND A VALVE STEM ON SAID HEAD CONNECTED WITH SAID DIAPHRAGM; (5) A VAPOR INLET TO THE VAPOR COMPARTMENT OF (3) FOR CONNECTING WITH A VAPOR SOURCE; (6) A CONDUIT CONNECTING THE FLUID PASSAGEWAY OF (4) INTERMEDIATE THE VALVE SEAT AND THE DIAPHRAGM OF (3) WITH THE SECOND COMPARTMENT OF (2); (7) A PORT IN THE FIRST COMPARTMENT OF (2) FOR CONNECTING SAME WITH A FLUID SOURCE; AND (8) A SPRING IN THE VAPOR PRESSURE COMPARTMENT OF (3) BIASING THE DIAPHRAGM THEREIN TOWARD THE VALVE HEAD ATTACHED THERETO; (9) CONDUIT MEANS CONNECTING THE PORT OF (7) AND THE FLUID PASSAGEWAY OF (4) ON THE SIDE OF THE VALVE SEAT REMOTE FROM THE DIAPHRAGM WITH SAID LINE DOWNSTREAM OF THE VALVE BODY OF (1); (10) CONDUIT MEANS CONNECTING THE FLUID PASSAGEWAY OF (4) INTERMEDIATE THE DIAPHRAGM AND THE VALVE SEAT THEREIN WITH SAID LINE UPSTREAM OF THE VALVE BODY OF (1); AND (11) MEANS CONNECTED TO A LOCATION UPSTREAM OF THE VALVE BODY OF (1) FOR DEVELOPING A VAPOR PRESSURE EQUAL TO THE VAPOR PRESSURE OF LIQUID AT SAID LOCATION, AND CONDUIT MEANS CONNECTING SAID DEVELOPED PRESSURE TO THE VAPOR INLET OF (5).