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:
Dec. 22, 2015
Filed:
Nov. 20, 2012
Dresser, Inc., Addison, TX (US);
Thomas Henry Cunningham, Canton, MA (US);
Dresser, Inc., Addison, TX (US);
Abstract
A trim assembly is provided with a cage with an internal surface and a cage port. A plug having an external surface is disposed in the cage and is operable between a closed position, a pressure balancing position and an open position. The trim assembly also includes a low friction flow restrictor disposed between the cage and the plug and a pressure energized seal disposed between the cage and the plug. A seal balancing volume defined by the internal surface of the cage, the external surface of the plug, the low friction flow restrictor and the pressure energized seal is provided. The seal balancing volume is in fluid communication with the cage port through the low friction flow restrictor and is maintained at a seal balancing volume pressure. The trim assembly further includes a pressure control assembly configured to vent the seal balancing volume.