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:
Dec. 05, 1978
Filed:
Mar. 10, 1977
Bolling A Abercrombie, Montgomery, TX (US);
McMurry Oil Tools, Inc., Houston, TX (US);
Abstract
A gas lift valve is characterized by a valve element biased to the first, closed, position within a valve housing by an extension spring biasing element. In the closed position the valve element interdicts communication between an annular region disposed externally to a production tubing string and the interior of the tubing string. A bellows arrangement may be provided and may have a fluid therewithin able to be pressurized to a predetermined pressure level to assist the spring biasing element in biasing the valve to the closed position. The extension spring element is disposed witin the valve housing above the bellows element. The valve element is itself physically disconnected from, but abutted against a bellows sub element which transmits the closing force to the valve element when the valve element is in the closed position. The valve element moves to the second, open, position when a combination of the forces generated by the pressure of the fluid within the annular region acting over the area of the valve seat and the pressure of a fluid within the production tubing acting over the area of the bellows arrangement are sufficient to overcome the closing force of the spring biasing element. Since the valve element is physically disconnected from the bellows sub element, the valve element interdicts communication between the annular region disposed externally to the production tubing string and the interior of the production tubing if the pressure of the fluid in the production tubing exceeds the pressure of the fluid in the annular region, thus acting as a check valve.