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. 22, 1995
Filed:
Apr. 11, 1994
Edward T Wood, Kingwood, TX (US);
Robert T Brooks, Corpus Christi, TX (US);
Michael O Dion, Houston, TX (US);
Derrel G Gurley, Katy, TX (US);
Monty E Harris, Azle, TX (US);
CTC International, Houston, TX (US);
Abstract
A stage valve with particular use in cementing a well bore annulus where the stage valve has pressure operated valve member for opening a flow passage in the stage valve and the valve member has differential pressure areas which maintain the valve member open while a fluid moves through the flow passage in one direction and which can be closed by fluid moving in an opposite direction. The flow passage has a choke to develop a pressure differential from the flow of fluid. Spring members can be used with the valve member to close the flow passage when the pressure differential of the fluid flow in one direction is insufficient to maintain the valve member in an open position.