Application of Impressed Current Cathodic Protection to Stainless Steel Hot-Water Storage Tanks (10065)
By Tsukasa Shirouzu, 1992. Class 1 pressure vessels made of stainless steel and used as hot-water storage tanks in hotels, hospitals, factories and similar buildings are often thought to be free of corrosion because they store fresh water. However, studies of past use have shown that corrosion and stress-corrosion cracking occur in crevices and welds. Repairs are seldom satisfactory and, although the cathodic protection method is effective, it is seldom used. This report investigates the optimum condition of cathodic protection for S 30408 stainless steel tanks in the anticipated corrosion environment and studies the application of an impressed current cathodic protection. The report finds that even this type of stainless steel, which is in general use today, can, through suitable cathodic protection, be a material with superior durability. Proper cathodic protection, however, requires that attention be given to electrode positioning and tank structure for uniform distribution of potential.