Drill pipe tester and safety valve
Patent 4319633 Issued on March 16, 1982. Estimated Expiration Date: 
April 3, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
April 3, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3347318 3509913 3667505 Combination subsurface safety valve and chemical injector valve Lubricator valve apparatus Tubing manipulated test valve and latch assembly Rod operated rotary well valve Patent #: 4230185 InventorsAssigneeApplicationNo. 06/136831 filed on 04/03/1980US Classes:166/250.08, Leak testing or locating166/321, Fluid pressure biased to open position position166/332.1, Longitudinally movable operator251/77LOST MOTION BETWEEN ACTUATOR AND VALVEExaminersPrimary: Pate, III, William F.Attorney, Agent or FirmInternational ClassesE21B 47/10 (20060101)E21B 34/00 (20060101) E21B 34/10 (20060101) AbstractA drill pipe tester valve includes a spherical valve member supported from an upward facing surface of a housing so that downward forces exerted on the valve member in its closed position, due to fluid pressure in a string of pipe above the valve member, are transmitted substantially entirely to said housing. A latching device is provided for latching the spherical valve member in its closed position as the string of pipe and tester valve are lowered into a well and for subsequently releasing the spherical valve member and allowing it to move to its open position when the string of pipe and tester valve are finally positioned within the well. | |
