A valve that is opened by applying hydraulic pressure and will close when the hydraulic pressure is removed. For example, actuated Xmas Tree valves and surface controlled subsurface safety valves (SCSSSVs) are fail-safe closed.
A valve that is opened by applying hydraulic pressure and will close when the hydraulic pressure is removed. For example, actuated Xmas Tree valves and surface controlled subsurface safety valves (SCSSSVs) are fail-safe closed.