Patent attributes
A pressure control valve is disclosed which includes an inlet; an outlet; a valve body between the inlet and the outlet; a piston having opposed smaller and larger ends each having a circumferentially extending piston wall, the piston being slideably received within the valve body and having a bore therethrough; a porting assembly for providing a fluid passageway between the inlet and the bore, and biasing means for biasing the piston against the pressure at the outlet towards a first position proximate the outlet from a second position proximate the inlet; wherein in the first position fluid communication is made between the inlet and the outlet via the porting assembly and the bore, and in the second position fluid communication between the inlet and the outlet is prevented by the circumferentially extending piston wall of the smaller end of the piston cooperating with the porting assembly to close the fluid passageway between the inlet and the bore.