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:
Jul. 31, 2007
Filed:
May. 05, 2006
Qiu Shi Zheng, Spring, TX (US);
Qiu Shi Zheng, Spring, TX (US);
FMC Technologies, Inc., Houston, TX (US);
Abstract
The present invention is directed to a pressure balanced fluid control device. In one illustrative embodiment, the device comprises a body, a bonnet coupled to the body, a valve stem operatively coupled to a gate positioned in the body, a valve stem seal positioned between the valve stem and the bonnet, wherein a sealed cavity exists above the valve stem seal, and an opening through the bonnet that is adapted to allow a pressure of a working fluid flowing through the valve to be exerted in the sealed cavity above the valve stem seal. In another illustrative embodiment, the device comprises a body, a bonnet coupled to the body, a valve stem operatively coupled to a gate positioned in the body, a valve stem seal positioned between the valve stem and the bonnet, wherein a sealed cavity exists above the valve stem seal, and an opening through the bonnet, the opening being in fluid communication with the sealed cavity and an interior region of the body. In a further illustrative embodiment, the device comprises a body, a bonnet coupled to the body, a valve stem operatively coupled to a gate positioned in the body, a valve stem seal positioned between the valve stem and the bonnet, wherein a sealed cavity exists above the valve stem seal, a piston chamber formed in the bonnet, the piston chamber being in fluid communication with the sealed cavity and an interior region of the body, and a piston positioned in the piston chamber.