Flow control device

Claim 1

A FLOW CONTROL DEVICE FOR REGULATING THE FLOW OF A LIQUID OF VARIABLE VISCOSITY AND VARIABLE PRESSURE COMPRISING A HOUSING HAVING AN INLET, AN OUTLET, AND A FLUID CHAMBER THEREBETWEEN, A VALVE OPENING DEFINED BY A VALVE SEAT BETWEEN THE FLUID CHAMBER AND THE OUTLET, A SLIDE MOVABLE TOWARD AND AWAY FROM THE VALVE SEAT TO THROTTLE THE FLOW OF LIQUID FROM THE CHAMBER TO THE OUTLET, MEANS FOR BIASING THE SLIDE MEMBER AWAY FROM THE VALVE SEAT, A PASSAGE THROUGH THE SLIDE MEMBER HAVING AN INLET END FOR RECEIVING LIQUID INTRODUCED INTO THE CONTROL, THE END OF THE SLIDE ADJACENT THE VALVE SEAT FORMED WITH AN ANNULAR KNIFE EDGE SURROUNDING THE PASSAGE, AND MEANS IN THE PASSAGE ADJACENT THE INLET INCLUDING AN INDIVIDUAL THIN PLATE HAVING AN ORIFICE THROUGH IT FOR RESTRICTING THE FLOW OF LIQUID INTRODUCED INTO THE INLET, MEANS TO POSITION THE THIN PLATE WITHIN THE PASSAGE, THE WALL DEFINING THE ORIFICE BEIONG LESS THAN A FEW THOUSANDTHS INCH THICK, THE COMBINATION PROVIDING A SUBSTANTIALLY CONSTANT RATE OF FLUID FLOW REGARDLESS OF CHANGES IN VISCOSITY AND PRESSURE OF FLUID.