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:
Feb. 26, 1991
Filed:
Jun. 06, 1990
John N Tervo, Scottsdale, AZ (US);
Allied-Signal Inc., Morris Township, Morris County, NJ (US);
Abstract
A method for opening a sealingly closed, balanced-torque butterfly valve, and apparatus adapted for use with the method. The butterfly valve (40) comprises a valve plate (42) having a peripherally disposed seal (162) seated in an annular recess (160). A flow passage (164, 166) is formed in the valve plate (42) and fluidically connects the recess (160) to the downstream-facing surface of the valve plate. A check valve (168) is disposed in the flow passage (164, 166) to alternately block or permit flow therethrough. Outwardly directed pressure exerted by high-pressure fluid on the seal (162) is relieved by opening the check valve (168) in reponse to a slight translational movement of the valve plate (42) relative to a rotatable shaft (72) which pivotally connects the valve plate to the duct (146).