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:
Jul. 18, 1978
Filed:
Mar. 28, 1977
Applicant:
Inventor:
Ervin Randermann, Jr, Beasley, TX (US);
Assignee:
Schlumberger Technology Corporation, New York, NY (US);
Primary Examiner:
Int. Cl.
CPC ...
E21B / ; F16K / ;
U.S. Cl.
CPC ...
166324 ; 137629 ; 13763015 ; 166334 ;
Abstract
In accordance with an illustrative embodiment of the present invention, a valve apparatus adapted to be incorporated in a string of tubing to permit pressure testing thereof in a well bore includes inner and outer members telescopically disposed and movable between extended and contracted relative positions, main valve means for closing the axial flow passage through said members to downward flow in response to extension of the members, and equalizing passage and valve means for equalizing pressures across the main valve prior to reopening thereof in response to contraction of the members.