| 摘要 |
<p>A subsea test tree comprising a housing 22 defining a flow path, a valve member 32 mounted in the housing and an actuator 28 coupled to the housing. A drive arrangement 34 extends through a wall of the housing to operatively connect the actuator to the valve. The actuator is operable to operate the valve member to control fluid flow along the fluid pathway. Also disclosed are improvements to actuators. The actuator may be isolated from a fluid environment within the housing, may lie flush to the housing and be located on diametrically opposite sides. The drive arrangement may comprise a drive structure, such as a drive shaft, may include a dynamic seal, may include a rotary valve and may be moveable in response to fluid pressure differential across a piston.</p> |
