Pressure regulating valve and combination on-off valve

Claim 1

A FLUID PRESSURE REGULATING VALVE COMPRISING: A VALVE HOUSING ADAPTED TO BE CONNECTED IN A FLUID FLOW LINE AND INCLUDING WALL MEANS DEFINING A VALVE CYLINDER MEMBER, A SURROUNDING ANNULAR PASSAGE, AND AN INWARD CONVOLUTION IN SAID PASSAGE DOWNSTREAM OF THE CYLINDER MEMBER; A VALVE PISTON MEMBER INCLUDING A SKIRT ELEMENT SLIDABLE IN SAID CYLINDER MEMBER AND A HEAD ELEMENT DISPOSED DOWNSTREAM OF SAID INWARD CONVOLUTION IN SAID HOUSING WALL MEANS TO DEFINE THEREWITH A FLOW CONSTRICTION THE OPEN AREA OF WHICH IS REDUCED BY UPSTREAM MOVEMENT OF THE VALVE PISTON MEMBER; FORCE LOADING MEANS FOR SAID VALVE PISTON MEMBER INCLUDING PASSAGE MEANS CONNECTING SAID CYLINDER MEMBER TO A FIRST REFERENCE PRESSURE SOURCE AT PRESSURE LEVEL RELATED TO THE LEVEL OF PRESSURE TO BE HELD BY THE REGULATING VALVE BY THE SAME PROPORTIONALITY AS BETWEEN THE EFFECTIVE AREAS OF SAID VALVE PISTON SKIRT AND HEAD ELEMENTS ON WHICH THESE PRESSURES RESPECTIVELY ACT; ON-OFF VALVE MEANS INCLUDING RELATIVELY MOVABLE VALVE AND VALVE SEAT ELEMENTS, ONE CARRIED BY SAID HOUSING WALL MEAN AND ONE BY SAID VALVE PISTON MEMBER, SAID ON-OFF VALVE ELEMENTS BEING OF EFFECTIVE AREA SMALLER THAN SAID VALVE PISTON SKIRT AND ARRANGED TO BLOCK FLUID FLOW THROUGH SAID HOUSING UPON TRAVEL OF SAID VALVE PISTON MEMBER TO ITS DOWNSTREAM EXTREME OF MOVEMENT; A SECOND REFERENCE PRESSURE SOURCE AT PRESSURE LEVEL SUBSTANTIALLY HIGHER THAN SAID FIRST SOURCE; AND VALVE MEANS OPERABLE IN A FIRST POSITION TO MAINTAIN SAID PASSAGE MEANS CONNECTED TO SAID FIRST REFERENCE PRESSURE SOURCE SO THAT SAID VALVE PISTON MEMBER WILL MOVE TO CONTROL THE OPEN AREA OF SAID FLOW CONSTRICTION IN RESPONSE TO THE REGULATED PRESSURE ACTING ON SAID VALVE PISTON HEAD ELEMENT AND TO SAID FIRST REFERENCE PRESSURE ACTING ON SAID VALVE PISTON SKIRT ELEMENT, AND OPERABLE IN A SECOND POSITION TO TRANSFER SAID CONNECTION TO SAID SECOND REFERENCE PRESSURE SOURCE TO CAUSE SAID VALVE PISTON MEMBER TO MOVE TO CLOSE SAID ON-OFF VALVE MEANS.