Gas lift valve

Claim 1

A GAS LIFT VALVE COMPRISING, A TUBULAR HOUSING, SPACED SEAL MEANS ON THE EXTERIOR OF THE HOUSING DEFINING THEREBETWEEN AN INTERMEDIATE SECTION OF THE HOUSING, A MAIN GAS PASSAGEWAY THROUGH THE HOUSING HAVING AN INLET IN SAID INTERMEDIATE SECTION AND AN OUTLET OUTSIDE SAID INTERMEDIATE SECTION, A VALVE SEAT IN SAID MAIN GAS PASSAGEWAY, A MAIN VALVE MEMBER COOPERABLE WITH THE VALVE SEAT TO CONTROL FLOW THROUGH THE PASSAGEWAY, A BOSS CARRIED BY THE HOUSING AND HAVING AN OUTER CYLINDRICAL SURFACE CONCENTRIC WITH THE BORE IN SAID HOUSING TO PROVIDE AN ANNULUS THEREBETWEEN, A MOTOR PISTON IN SAID ANNULUS SEALINGLY ENGAGING SAID HOUSING AND CYLINDRICAL SURFACE AND HAVING ONE ENDWISE FACE EXPOSED TO SAID INLET, MEANS CONNECTING SAID VALVE MEMBER AND PISTON TOGETHER, A PASSAGEWAY EXTENDING THROUGH SAID VALVE MEMBER AND PISTON AND CONNECTING MEANS, A PASSAGEWAY EXTENDING THROUGH SAID BOSS AND IN FLUID COMMUNICATION WITH THE PASSAGEWAY THROUGH SAID PISTON, A PILOT VALVE SEAT IN SAID BOSS PASSAGEWAY, A PILOT VALVE MEMBER COOPERABLE WITH SAID PILOT VALVE SEAT TO CONTROL FLOW THERETHROUGH, A PILOT GAS PASSAGEWAY BETWEEN SAID PILOT VALVE SEAT AND SAID INTERMEDIATE SECTION OF THE HOUSING, SAID PILOT HAS PASSAGEWAY HAVING A BLEED SECTION PROVIDING A PRESSURE DROP THEREACROSS WHEN THE PILOT VALVE MEMBER IS IN OPEN POSITION, MEANS ESTABLISHING FLUID COMMUNICATION BETWEEN THE OTHER ENDWISE FACE OF SAID PISTON AND SAID PILOT GAS PASSAGEWAY BETWEEN SAID BLEED SECTION AND SAID PILOT VALVE SEAT, AND PRESSURE RESPONSIVE MOTOR MEANS FOR MOVING SAID PILOT VALVE MEMBER BETWEEN OPEN AND CLOSED POSITIONS.