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U.S. Department of Energy
Office of Scientific and Technical Information

Oil and gas well safety valve

Patent ·
OSTI ID:5751853
An oil or gas well safety valve is described comprising: a valve body having a valve seat therein, a flapper valve, hinge means for supporting the valve from the valve body, control means, positioned within the valve body and to side of the valve to which the valve opens, for engaging the valve at a point removed from the hinge means from selectively applying a force to the valve to pivot the valve between its closed and opened position. The control means comprises a cylinder having upper, intermediate and lower chambers, a control piston moveable in the upper chamber, a control link attached between the control piston and the valve for transmitting the movement of the control piston to the valve and a primary piston moveable in the intermediate chamber.
Assignee:
NOV; NOV-88-088462; EDB-88-015095
Patent Number(s):
US 4706933
OSTI ID:
5751853
Country of Publication:
United States
Language:
English