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U.S. Department of Energy
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Pressure charged low spread safety valve

Patent ·
OSTI ID:6137355
A well safety valve is described for controlling the fluid flow through a well conduit and including a tubular housing having the following: a bore and a value closure member moving between open and closed positions; and a longitudinal tubular member telescopically movable in the housing for controlling the movement of the vale closure member. The improvement is for moving the tubular member in a first direction for causing the valve closure member to move to the closed position and for moving the tubular member in a second direction for opening the valve closure member comprising: a piston and cylinder assembly having a seal positioned in the housing, and one of which is connected to the tubular member; one side of the assembly and seal in communication with a hydraulic passageway adapted to extend to the well surface for actuating the tubular member in the second direction to open the valve closure member; a pressurized closed U-shaped chamber in the housing in communication with the second side of the assembly and the seal acting to move the tubular member in the first direction. The chamber extends from a position below the seal of the piston and cylinder assembly to a position above the seal; the chamber includes a pressurized gas in the chamber and a hydraulic fluid in the chamber between the gas and the seal. This lubricates and prevents the gas from contacting the seal.
Assignee:
Camco, Inc., Houston, TX
Patent Number(s):
US 4676307
OSTI ID:
6137355
Country of Publication:
United States
Language:
English