Abstract: An electro hydraulic actuator with built-in fail safes is provided. Multiple accumulators are integrated into the actuator to improve reliability and redundancy. One or more accumulators can fail and the remaining accumulators provide sufficient energy to move the actuator to its fail-safe condition.

Abstract: A pressurized sealing arrangement suited for providing a seal between a valve stem and a valve body is provided. The sealing arrangement includes a piston that is restrained in and statically sealed to the valve body and which surrounds the valve stem. Contained within the piston is an annular seal packing that includes two sealing elements spaced apart by a spacer element. The piston includes a face acted upon by a process fluid flowing through the valve body in such a manner that the piston exerts pressure upon a lubricant cavity. The lubricant cavity is in fluid communication with the seal packing such that lubricant contained therein forms a lubricant ring around the stem. Lubricant is also thereby supplied to sealing elements of the packing seal. To prevent contamination of the seal packing, a removable cover is provided that encloses the piston and seal packing.

Abstract: An electrical actuator is particularly suited for driving a wellhead valve for regulating the flow of natural gas from a production well. The electrical actuator can be driven using the existing local power supply in wellhead valve systems, typically a solar panel and a battery. The electrical actuator may include a gear reduction train, a brake and a manual input override with clutch protection. The electrical actuator can be configured in three different operational modes that provides a predetermined position upon power loss including fail-bias fixed, fail open and fail bias closed.

Abstract: An electrical actuator is particularly suited for driving a wellhead valve for regulating the flow of natural gas from a production well. The electrical actuator can be driven using the existing local power supply in wellhead valve systems, typically a solar panel and a battery. The electrical actuator may include a gear reduction train, a brake and a manual input override with clutch protection. The electrical actuator can be configured in three different operational modes that provides a predetermined position upon power loss including fail-bias fixed, fail open and fail bias closed.

Abstract: A pressurized sealing arrangement suited for providing a seal between a valve stem and a valve body is disclosed. The sealing arrangement includes a piston that is restrained in and statically sealed to the valve body and which surrounds the valve stem. Contained within the piston is an annular seal packing that includes two sealing elements spaced apart by a spacer element. The piston includes a face acted upon by a process fluid flowing through the valve body in such a manner that the piston exerts pressure upon a lubricant cavity. The lubricant cavity is in fluid communication with the seal packing such that lubricant contained therein forms a lubricant ring around the stem. Lubricant is also thereby supplied to sealing elements of the packing seal. To prevent contamination of the seal packing, a removable cover is provided that encloses the piston and seal packing.