Valve actuator
AssigneeTelektron Limited
InventorDennis S. Dowdall
Life of this patent
Estimating the term…
Abstract
A valve actuator for a subsea oil well installation includes a rotatable adjusting member (53) for engagement with the valve spindle, and a linear fluid actuator (17) coaxial with the adjusting member and operable by fluid pressure pulses to index the adjusting member around selectively in either direction. A mechanical movement converts linear motion of the actuator to rotary motion of the adjusting member. A fluid operated clutch selectively connects the fluid actuator to the adjusting member. A shaft (65) projects from the rear end of the actuator casing to permit manual adjustment as well. Position sensors (120) emit signals indicative of the valve position, and a pointer (123) at the rear of the casing provides a visual indication of the valve condition.
Claims22
A valve actuator comprising a support frame, a rotatable valve adjusting member carried by the frame for engagement with a valve spindle, fluid actuating means mounted on the frame substantially coaxially with said valve adjusting member, the fluid actuating means defining two chambers and including a reciprocable output member having a normal position, said chambers having means for supplying fluid pressure signals thereto for actuating said output member to reciprocate in opposite directions from said normal position, a rotatable driving member, means for converting linear movement into rotational movement coupled between said output member and said driving member, rotation transmitting means to connect kinematically the driving member to the valve adjusting member for rotation of the driving member to rotate the valve adjusting member, fluid pressure operable means for engaging said rotation transmitting means for the driving member to rotate the valve actuating member during a working stroke of the output member away from said normal position and for disengaging said rotation transmitting means for the driving member to rotate independently of the valve adjusting member during a return stroke of the output member towards said normal position, whereby fluid pressure signals supplied to said fluid operable means and to the respective chambers of the fluid actuating means cause the valve adjusting member to be indexed around selectively in opposite directions of rotation of said member for adjusting the spindle of a valve to which the actuator is connected.
A valve actuator comprising a support frame, a rotatable valve adjusting member carried by the frame for engagement with a valve spindle, linear fluid actuation means mounted on the frame substantially coaxially with said valve adjusting member, means for converting linear movement into rotation including a slide member coupled to the linear fluid actuator means to be driven thereby in opposite direction from a central position, a sleeve member and means acting between the slide member and sleeve member for the sleeve member to be rotated in response to displacement of the slide member longitudinally of the sleeve member, disengageable rotary driving means including a driving member fast with said sleeve member, and a driven member fast with said valve adjusting member, a spring device coupled to the sleeve member normally to hold the driving member in a position disengaged from the driven member, the driving member being movable in either of two directions from the disengaged position to engage the driven member, fluid pressure actuated means coupled to the sleeve member to shift the sleeve member axially to engage the driven member, means for supplying fluid pressure signals to the linear fluid actuating means and the fluid pressure actuated means to displace the sleeve member axially to engage the driving and driven members and then rotate the sleeve, whereby the actuator is operable to index the valve adjusting member around in opposite directions of rotation, and a device coupled to the valve adjusting member to enable the adjusting member to be rotated manually when the rotary driving means is disengaged.
Dependencies are inferred from the claim text.