Abstract: An electrically operated hydraulic valve comprises a valve assembly that provides a common valve passageway, an inlet port, an outlet port and a return port connected to the passageway and an axially movable valve device which allows in a first position fluid flow between the outlet port and the return port while closing the inlet and in a second position, axially displaced from the first position, fluid flow between the inlet port and the outlet port while closing the return port. A spring provides a restoring force urging the valve device to its first position. An electrically operated actuator coupled to the valve device comprises a permanent magnet and a cooperating electrical coil having an associated magnetic core, one or other of the magnet and the coil constituting a stator and the other constituting an armature which is coupled to the valve device to move it from the first position to the second position.

Abstract: A reciprocable connector assembly for coupling a service line through a path in a wellhead and hangar wall, the assembly comprising: connector for coupling with a corresponding connector disposed in the hangar wall; a shuttle carrying said connector between a first position in which the connector is not coupled to the corresponding connector and a second position in which it is coupled, at least one service line connected at one end to the connector and wound in a plurality of turns to extend or retract with respect to one another as the shuttle moves between the first and second positions and a support for constraining movement of the turns.

Abstract: A pre-tensioning arrangement for inner and outer elongate concentric members includes a load member which is axially movable in an actuating direction relative to the inner member and has an outer surface which tapers in the actuating direction, a laterally expansible ring which is engaged by the load member in an inclined engagement zone during the actuating movement, and an engagement zone between the laterally expansible ring and the outer member, the engagement zones providing a mechanical advantage between the movement of the load member and movement of the outer member.