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:
Sep. 11, 1990
Filed:
Feb. 01, 1989
Applicant:
Inventors:
Thomas F Bailey, Houston, TX (US);
Raymond A Todd, Jr, Houston, TX (US);
Assignee:
Drilex Systems, Inc., Houston, TX (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
F16K / ;
U.S. Cl.
CPC ...
137 71 ; 137327 ; 1374939 ; 137515 ; 166317 ; 166325 ;
Abstract
A mud saver valve for insertion within the drill string to retain mud in the drill pipe preventing the mud column from flowing past the valve when pumping is interrupted. The mud saver valve includes an internal check valve which permits increased flow of mud upward through the valve when a predetermined downhole pressure is reached. The increased flow of the check valve prevents a blow-out of the plug spear in the event sudden upward pressure is encountered. The check valve forms a part of the plug spear which is removable from the mud saver valve to facilitate the running of wireline tools.