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:
May. 25, 1999
Filed:
Jan. 12, 1998
Gregory N Gilbert, Missouri City, TX (US);
Curry B Walker, Sulphur, LA (US);
Sigma Scientific Technology, Inc., Houston, TX (US);
Abstract
An improved ball valve for lethal gas or fluid service is disclosed having a novel triple redundant stem to bonnet seal design. A ceramic seal ring forms the primary stem to bonnet seal. The ceramic seal ring has a first seal surface lapped for sealing engagement with a corresponding lapped surface on the stem and a second seal surface lapped for sealing engagement with a corresponding lapped surface on the bonnet. The ceramic seal ring first seal surface lapped for sealing engagement with a corresponding lapped surface on said stem and the corresponding lapped surface on the stem may be frustoconically or spherically shaped. An elastomeric seal and a compression type seal between the stem and bonnet act as redundant seals. A preloading means to maintain the ceramic seal ring and lapped sealing surfaces on the bonnet and stem in sealing engagement is shown.