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:
Nov. 14, 1989
Filed:
Apr. 26, 1989
James S Stubbe, Milwaukee, WI (US);
James L Chevalier, Mequon, WI (US);
Edwin C Pow, Menomonee Falls, WI (US);
A. O. Smith Corporation, Milwaukee, WI (US);
Abstract
A cathodically protected water heater which eliminates the need of a conventional anode rod. The water heater tank includes a cylindrical shell enclosed by upper and lower heads and a flue which is mounted within openings in the lower and upper heads. The outer surface of the flue as well as the upper surface of the lower head is coated with a metal anodic to steel, and the metal coating on the flue extends continuously from the lower head to a location above the upper head. The remainder of the inner surface of the heater is also coated with the anodic metal. The anodic metal is applied in a sufficient thickness at least at the junction of the lower end of the peripheral flange of the upper head and the shell to bridge and seal the crevice opening which typically exists between the free end of the upper head flange and the shell wall. The coating over the crevice hydraulically seals the exterior weld between the upper head and shell from water contained in the heater and provides a corrosion barrier and anodic surface to contained water. Where welds are provided through the metal coating at the upper head/flue and shell/lower head junctions, the metal coating flows about the welds to also hydraulically seal them off from contained water and provide a corrosion barrier and anodic surface to contained water.