A ball valve is provided. The ball valve includes at least one load varying mechanism provided in the static body assembly. The load varying mechanism includes a biasing member pressing one of the ball seat seals against the outer surface of the ball of the ball valve with a variable sealing load force applied on the ball, toward the ball and coaxial with the direction of the fluid. The load varying mechanism also includes a movable member operatively connected to a cam and to the biasing member, a rotation of the cam translating the movable member coaxially to the direction of the fluid, in order to variably load the biasing member toward or away from the ball, based on the different positions of the ball.

The present invention refers to a valve actuator device comprising an upper plate and a lower plate facing each other, defining a housing inside which a cylinder with a stem is housed. The stem is connected to a rotor arm by a guiding element inserted and slidably in line between a lower position and an upper position within guiding grooves arranged in the respective upper plate and lower plate. The rotor arm is configured to rotate about a rotation axle arranged in a rotating element. The valve actuator device may include a position sensor system for detecting an open position and a closed position. The valve actuator device may include a manual override system for manually opening or closing the valve.

A wellhead valve includes a rotatable valve plug driven by the rotation of a drive stem. The valve further includes complementary camming surfaces that are engaged by rotation of the drive stem and that when engaged create a force on the valve plug that forces a sealing surface of the valve plug into a corresponding sealing surface of a valve seat to thereby create a seal between the sealing surfaces. The valve may include a helical-spline rotary actuator to drive rotation of the drive stem, which in turn drives rotation of the valve plug into (or out of) the sealing position and the complementary camming surface into (or out of) engagement. The rotary actuator may be hydraulic.

The present invention refers to a valve actuator device comprising an upper plate and a lower plate facing each other, defining a housing inside which a cylinder with a stem is housed. The stem is connected to a rotor arm. The rotor arm is configured to rotate about a rotation axle arranged in a rotating element. The valve actuator device may include a position sensor system for detecting an open position and a closed position. The valve actuator device may include a manual override system for manually opening or closing the valve.

An apparatus includes a valve yoke comprising a hollow inner portion and an upper face, an adapter plate including a through-hole and a lower face, wherein the lower face provides an interface for connection to the upper face of the valve yoke, an actuator assembly having an exterior profile, wherein the actuator assembly is removably retained within the hollow inner portion, and a drive screw retained between the actuator assembly and the adapter plate. The drive screw is rotatable within the through-hole along an axis of rotation. The axis of rotation is parallel to an axis of reciprocation. The actuator assembly comprises a first axial cam and a first indexing pin rotatably driven by the drive screw to follow the first axial cam.