Patent ID: 8267107

Claim:
A valve, comprising: a valve housing; a bore in the valve housing; an inlet supply port fluidly communicating a pressurized supply fluid to the bore; a piston movably positioned in the bore based on the pressure of the supply fluid, a portion of the piston extending into a frusto-conically shaped portion of the bore, a sealing member associated with the portion of the piston sealingly engaging a surface of the frusto-conically shaped portion of the bore based on the pressure of the supply fluid; an inlet valve, movably positioned in the bore, biased to sealingly engage a wall of the bore based on the pressure of the supply fluid; a control pressure supply port fluidly communicating a pressurized control fluid to the bore through the valve housing; a control pressure delivery port fluidly communicating with the control pressure supply port, via the bore, based on the pressure of the supply fluid; and a venting port fluidly communicating with the control pressure delivery port, via the bore, based on the pressure of the supply fluid.