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. 29, 1981
Filed:
Feb. 27, 1980
John K McGee, Houston, TX (US);
Combustion Engineering, Inc., Windsor, CT (US);
Abstract
In a gate valve, which has a backseat which is made up only when the normally non-rising operator stem is permitted to rise a short distance, and in order that a smaller-diameter stem may be used than one which is of sufficient area where it passes through the stem packing to cause the internal pressure within the valve cavity to generate sufficient force to overcome the frictional forces resisting stem movement developed by the internal pressure between the gate plates and the seats, so that the stem may rise when it is supposed to, to make the backseat, a system of clearances is provided between the stem nut and the gate plates. A different stop arrangement is shown for limiting rising of the gate, for defining the fully open position of the gate.