Control valve responsive to fluids of different densities

Claim 1

A CONTROL VALVE RESPONSIVE TO FLUIDS OF DIFFERENT DENSITIES PREVENTING THE FLOW OF HIGHER DENSITY FLUID IN ONE DIRECTION UNLESS LOWER DENSITY FLUID PREVIOUSLY HAS BEEN FLOWING FOR A SHORT TIME IN THE OPPOSITE DIRECTION, COMPRISING: A HOUSING HAVING AN UPWARDLY TAPERING TOP PORTION, A DOWNWARDLY TAPERING BOTTOM PORTION AND A SIDE PORTION ENCLOSING A SPACE ADAPTED TO BE FILLED SUCCESSIVELY WITH TWO FLUIDS OF DIFFERENT DENSITIES; A FIRST SEAT SURROUNDING A FIRST PORT AT THE UPPERMOST PART OF SAID TOP PORTION; A FIRST EXTERNAL DUCT LEADING FROM SAID FIRST PORT AND ADAPTED TO PASS LOWER DENSITY FLUID INTO SAID HOUSING AND HIGHER DENSITY FLUID OUT OF SAID HOUSING; A SECOND SEAT SURROUNDING A SECOND PORT AT THE LOWERMOST PART OF SAID BOTTOM PORTION; A SECOND EXTERNAL DUCT LEADING FROM SAID SECOND PART AND ADAPTED TO PASS HIGHER DENSITY FLUID OUT OF SAID HOUSING; A BALL OF DENSITY INTERMEDIATE THE DENSITIES OF SAID TWO FLUIDS WITHIN SAID HOUSING, SAID BALL SEALING WITH SAID FIRST SEAT WHEN SAID HOUSING CONTAINS NON-FLOWING FLUID OF HIGHER DENSITY AND SEALING WITH SAID SECOND SEAT WHEN SAID HOUSING CONTAINS FLUID OF LOWER DENSITY; AND MEANS RESTRAINING SAID BALL FROM RETURNING TO SAID FIRST SEAT FROM SAID SECOND SEAT DURING THE FLOW OF THE HIGHER DENSITY FLUID THROUGH SAID HOUSING IN SAID ONE DIRECTION AND PERMITTING SAID BALL TO RETURN TO SAID FIRST SEAT WHEN SAID FLOW TERMINATES, SAID MEANS INCLUDING A THIRD EXTERNAL DUCT LEADING INTO SAID HOUSING AND DIRCTING A STREAM OF HIGHER DENSITY FLUID INTO SAID HOUSING AT SAID BALL WHEREBY SAID STREAM COOPERATES TO RESTRAIN SAID BALL FROM RETURNING TO SAID FIRST SEAT.