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:
Jun. 14, 1994
Filed:
Nov. 26, 1991
John Beson, Houston, TX (US);
Foster Oilfield Equipment Company, Houston, TX (US);
Abstract
A gate valve [10] is disclosed having a secondary seal, wherein the gate [15] forms a metal to metal seal with the seat [29, 134] and wherein a resilient seal [36a] is moved toward the gate [15] in a closed position to form a secondary fluid-tight seal with the gate [15]. A device [31, 34] for deenergizing the secondary seal is provided in order to prevent wear of the secondary seal upon opening of the gate and also to reduce the gate [15] drag caused by the energized secondary seal. Also disclosed is a pressure relief mechanism [40, 141] for the secondary seal adapted to prevent damage to the seal and a mechanism for evenly applying opposing secondary seals.