CATHODICALLY PROTECTED WATER HEATER

摘要

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. The upper surface of the lower head is coated with a metal anodic to steel. The inner surface of the shell and the upper head are coated with a corrosion resistant coating, such as glass or metal anodic to steel as well, and the upper edge of the flange in the upper head bordering the opening is welded directly through the metal coating to a flue which passes through the shell while the outer periphery of the lower head is welded to the lower edge of the shell. The metal coating 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.