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. 01, 1999
Filed:
Apr. 23, 1998
Bradley W Mosman, Shawnee, OK (US);
ERC Industries, Inc., Houston, TX (US);
Abstract
A back seat rising stem gate valve has a valve body with a flow passageway through it and an open top, a gate that is vertically positioned to open and close the passageway, a stem extending upwardly from the valve body, the lower end of the stem being attached to the gate, a bonnet secured to the valve body by which the valve body open top is closed, the stem extending through an opening in the bonnet, a packing box slidably positioned in an opening in the bonnet and receiving the stem, the packing box having a back seat circumferential sealing surface surrounding the valve stem, and the valve stem having an integral enlarged diameter shoulder so that when the stem is in the full upward position the packing box can be displaced downwardly forcing the back seat sealing surface to seal against the stem shoulder to seal against fluid leakage along the valve stem. In one embodiment the packing box is downwardly displaced by hydraulic pressure, such as hydraulic pressure supplied from within the valve body.