Patent ID: 7757710

Claim:
A pressure regulator comprising: a body having a pressure inlet; a bonnet having a pressure outlet and being operatively coupled to the body; and a piston assembly internally disposed between the body and the bonnet for selectively engaging a seat ring within the body for controlling a fluid flowing from the pressure inlet to the pressure outlet, wherein the piston assembly comprises: a piston having a piston head and a piston base including a bore therethrough to couple the pressure inlet to the pressure outlet, the piston having a first effective sensing area for a first operational mode and a second effective sensing area for a second operational mode; a loading element operatively coupled to the piston to provide a loading force on the piston to predetermine an outlet pressure; an adjustment means, disposed in the piston bore, for adjusting the outlet pressure; and a piston seat to engage the seat ring for fluid control, wherein the piston seat circumferentially engages the piston base.