The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 29, 2000
Filed:
Aug. 31, 1998
Clifford H Beall, Broken Arrow, OK (US);
Baker Hughes Incorporated, , US;
Abstract
An improved control system, particularly useful for SSVs, is disclosed. The control system has an operating piston which acts on a flow tube to move a flapper to an open position. The flapper is spring-loaded to close when the flow tube moves up. A return spring acts on the piston to lift the flow tube to allow the flapper to close. The operating piston is exposed to a control line from the surface as well as to a bypass piston. Opposing the hydrostatic forces of the control line is a pressurized chamber with a pressure in excess of the hydrostatic pressure. A secondary chamber acts on one side of the equalizing piston and is pressurized to a pressure less than the anticipated hydrostatic pressure in the control line. The system, including the operating piston, is configured so that when leakage occurs into or out of the control system in many places, the SSV will fail toward its failsafe closed position.