Abstract: An electrically operated valve actuator effective for shifting a valve (10) between open and closed positions is disclosed, the valve actuator comprising a movable member in the form of a valve stem (21) connected to a valve body (14), the movable member being driven by an electric motor (22) in linear motion between valve closing and valve opening positions, wherein electrical power to the motor is supplied via a current (25) control including a supplied current detection device. The movable member is designed for an idling length of travel (L) in the opening and closing directions during which the valve (10) is either fully open or fully closed, and the movable member is associated with buffer means (30) that during the idling length of travel gradually increases the torque and power required to move the movable member further in the open and closed positions of the valve (10), respectively.

Abstract: A subsea valve actuator is disclosed, comprising an override shaft (6) reaching from inside a fluid filled and pressure compensated actuator housing (1) to the exterior thereof via a bearing and sealing arrangement (7), wherein a visual valve position indicator (14) is arranged exterior to the actuator housing. The visual indicator (14) is pivotally mounted to the override shaft and guided non-rotatably to be forced in axial displacement on the override shaft when the override shaft is rotated, wherein the mounting of the visual indicator (14) on the override shaft (6) is encased in a fluid filled, pressure compensated indicator mounting enclosure (19) surrounding the override shaft (6) in sealing (26) relation outside of the actuator housing (1).

Abstract: A sub sea valve actuator system including a piston and cylinder assembly and a return spring arranged in an actuator housing, a hydraulic pump and electric motor assembly associated with the piston and cylinder assembly, and hydraulic flow lines for hydraulic medium driving the piston and cylinder in relative displacement against a force of the return spring. The valve actuator system includes a detector configured to detect an end-of-stroke position of the piston and cylinder assembly. The detector includes at least one of: a motor current monitoring circuit unit, a hydraulic medium pressure sensor unit, a position sensor unit, and a linear variable differential transformer unit. An electromechanical arresting mechanism is arranged to be energized for releasably arresting the return spring in a compressed state in result of the detected end-of-stroke position.

Abstract: A gate valve actuator including a stem that is movable linearly in an actuator housing connectable to the gate valve. The stem acts on the gate valve to shift the gate valve between open and closed positions, respectively. The stem is driven by a motor in a first direction into a steady state operation position. In the position the stem is biased in a second opposite direction towards a shutdown position by a spring member acting on the stem. A trigger mechanism is arranged for holding the spring member in a compressed state. The trigger mechanism includes an electrically controllable trigger that is arranged for release of the spring member in result of de-energizing the electrically controlled trigger. A method for shifting a gate valve between a steady state operation mode and a shutdown mode utilizing the gate valve actuator.

Abstract: An electrically operated valve actuator effective for shifting a valve (10) between open and closed positions is disclosed, the valve actuator comprising a movable member in the form of a valve stem (21) connected to a valve body (14), the movable member being driven by an electric motor (22) in linear motion between valve closing and valve opening positions, wherein electrical power to the motor is supplied via a current (25) control including a supplied current detection device. The movable member is designed for an idling length of travel (L) in the opening and closing directions during which the valve (10) is either fully open or fully closed, and the movable member is associated with buffer means (30) that during the idling length of travel gradually increases the torque and power required to move the movable member further in the open and closed positions of the valve (10), respectively.

Abstract: A method and an apparatus for establishing a hydrate free regime in a subsea production flowline before discharging into the subsea production flowline a production flow of hydrate prone hydrocarbon product pursuant to a shutdown or at an initial start of production. The hydrate free regime is achieved by injecting into the flowline a heated water volume in advance of discharging the hydrocarbon product from the subsea production system.

Abstract: A subsea valve actuator is disclosed, comprising an override shaft (6) reaching from inside a fluid filled and pressure compensated actuator housing (1) to the exterior thereof via a bearing and sealing arrangement (7), wherein a visual valve position indicator (14) is arranged exterior to the actuator housing. The visual indicator (14) is pivotally mounted to the override shaft and guided non-rotatably to be forced in axial displacement on the override shaft when the override shaft is rotated, wherein the mounting of the visual indicator (14) on the override shaft (6) is encased in a fluid filled, pressure compensated indicator mounting enclosure (19) surrounding the override shaft (6) in sealing (26) relation outside of the actuator housing (1).

Abstract: A sub sea valve actuator system including a piston and cylinder assembly and a return spring arranged in an actuator housing, a hydraulic pump and electric motor assembly associated with the piston and cylinder assembly, and hydraulic flow lines for hydraulic medium driving the piston and cylinder in relative displacement against a force of the return spring. The valve actuator system includes a detector configured to detect an end-of-stroke position of the piston and cylinder assembly. The detector includes at least one of: a motor current monitoring circuit unit, a hydraulic medium pressure sensor unit, a position sensor unit, and a linear variable differential transformer unit. An electromechanical arresting mechanism is arranged to be energized for releasably arresting the return spring in a compressed state in result of the detected end-of-stroke position.

Abstract: A hybrid process control system including electrical transmission of power to a sub-sea hydraulic power unit, which in turn provides hydraulic power for control of hydraulic actuators. A circulation system using small bore tubing in the umbilical cord in combination with a traditional topside hydraulic power unit provides for active control of hydraulic fluid quality with respect to contamination caused by the sub-sea hydraulic actuators, especially process gas from down hole safety valves. Thus, a more economical power transmission is achieved without reduction of fluid quality, which is essential to system integrity and reliability. Also, a significant enhancement of power transmission without a dramatic increase in the size of hydraulic supply and return lines is achieved. Fluid environmental issues are reduced to a negligible aspect.

Abstract: A gate valve actuator including a stem that is movable linearly in an actuator housing connectable to the gate valve. The stem acts on the gate valve to shift the gate valve between open and closed positions, respectively. The stem is driven by a motor in a first direction into a steady state operation position. In the position the stem is biased in a second opposite direction towards a shutdown position by a spring member acting on the stem. A trigger mechanism is arranged for holding the spring member in a compressed state. The trigger mechanism includes an electrically controllable trigger that is arranged for release of the spring member in result of de-energizing the electrically controlled trigger. A method for shifting a gate valve between a steady state operation mode and a shutdown mode utilizing the gate valve actuator.

Abstract: A method and an apparatus for establishing a hydrate free regime in a subsea production flowline before discharging into the subsea production flowline a production flow of hydrate prone hydrocarbon product pursuant to a shutdown or at an initial start of production. The hydrate free regime is achieved by injecting into the flowline a heated water volume in advance of discharging the hydrocarbon product from the subsea production system.

Abstract: A method for generating power at sub sea level. An oxidizing fluid and oxidizer are fed separately for mixing at a sub sea station. The oxidizing fluid and oxidizer are chosen for chemical reaction in situ under the release of energy. The energy so produced is fed to drive means operated by at least one of heat, kinetic energy, pressure and electricity, and operative to drive sub sea processes or/and sub sea production equipment. An apparatus for generating power at sub sea level. The apparatus includes separate supplies of an oxidizing fluid and an oxidizer for mixing at a sub sea station. The oxidizing fluid and oxidizer are chosen for chemical reaction in situ under the release of energy. A feed for feeding the energy so produced to a drive operated by at least one of heat, kinetic energy, pressure and electricity.

Abstract: A hybrid process control system including electrical transmission of power to a sub-sea hydraulic power unit, which in turn provides hydraulic power for control of hydraulic actuators. A circulation system using small bore tubing in the umbilical cord in combination with a traditional topside hydraulic power unit provides for active control of hydraulic fluid quality with respect to contamination caused by the sub-sea hydraulic actuators, especially process gas from down hole safety valves. Thus, a more economical power transmission is achieved without reduction of fluid quality, which is essential to system integrity and reliability. Also, a significant enhancement of power transmission without a dramatic increase in the size of hydraulic supply and return lines is achieved. Fluid environmental issues are reduced to a negligible aspect.