Patent ID: 8051812

Claim:
A valve actuator, comprising: a housing defining a longitudinal axis and first and second directions; an actuation mechanism whereby generating actuation force at least in the first direction; a rod operably connected with at least one part of the actuation mechanism and being moveable along the longitudinal axis; a valve positioned in a passage, said valve including a valve head and a valve stem, with the valve stem extending from the valve head in the first direction and operably connected with a second direction end of the rod, and the valve traveling in the first direction to open and in the second direction to close; a return spring including at least one mechanical compression spring operably connected with the valve and biasing the valve in the second direction; and a pneumatic booster operably connected with the valve and biasing the valve in the first direction, wherein the pneumatic booster includes a pneumatic cylinder, a pneumatic piston, slideably disposed in the pneumatic cylinder for at least part of a travel range of said pneumatic piston, and a charge mechanism for charging the pneumatic cylinder using high pressure gas from said passage.