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. 14, 1985
Filed:
Apr. 01, 1983
Tomoyuki Ueda, Nobeoka, JP;
Abstract
A butterfly valve resistant to corrosive gases. The valve body carries a valve seat ring having an elastic layer and an inner lining layer composed of polyvinylidene difluoride. The moisture permeability of the elastic layer is higher than that of the lining layer. On the outer surface of the valve seat ring facing the valve body, annular grooves are formed. Through the wall of the valve body, there are formed vents for moisture. These annular grooves and vents for moisture are communicated with each other. When the moisture contained in corrosive gases permeates through the lining and elastic layers, such moisture will easily be drained through the vents. Thereby, moisture permeated through the valve seat ring will not accumulate between the valve seat ring and the valve body. This prevents deformation of the valve seat ring, and extends valve use.