Importance

Loading Importance Indicators...

Abstract

The following invention relates to an actuator for controlling a valve (100) in a subsea installation, the valve having a spring (108) to return the valve to a failsafe condition upon loss of pressure. The actuator comprises an actuator module (10) that is exchangeably connected to the valve and comprising a cylinder with a movable piston (14), the piston being mechanically connected to said valve element, a fluid pump (47) operatively connected to said hydraulic cylinder, said pump adapted to supply fluid through a first hydraulic line (36) operatively connected between said hydraulic cylinder and said pump, said hydraulic line supplying a sufficient pressure to move the piston to said second position to cause the valve element to move to its second position, and a second hydraulic line (48) providing a fluid passage between the first hydraulic line and a reservoir (44) whereby a bypass control unit (39) is located in said second hydraulic line and comprising a movable element operating to open or close said fluid passage through the second hydraulic line providing a failsafe function to the valve. According to the invention a third hydraulic line (49) is connected to the second hydraulic line and acting on the movable element, forcing the control unit towards opening said passage.

Loading the Abstract Image...

First Claim