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:
Mar. 18, 1980
Filed:
Jun. 05, 1978
Glen E Lochte, Houston, TX (US);
Lionel J Milberger, Spring, TX (US);
FMC Corporation, San Jose, CA (US);
Abstract
A hydraulic valve operating circuit for providing positive opening and closing of a downhole safety valve includes shut-off valves which prevent leakage of fuel to the outside environment if a leak should occur in the hydraulic lines which are connected to the hydraulic actuator of the downhole safety valve. A hydraulic control line is connected to the actuator of the safety valve through a normally-closed shut-off valve and the hydraulic control line is also connected to the actuator of the shut-off valve to hold both the shut-off valve and the downhole safety valve open when the hydraulic line is pressurized. Another valve moves to a position to direct the flow of fluid from the safety valve to an accumulator when the pressure in the control line falls below a predetermined value to insure that the downhole safety valve will close properly.