2013 Volume 62 Issue 11 Pages 434-438
Galvanic corrosion has been observed in galvanized steel pipes and steel pipes connected to stainless steel, copper and copper alloy in building piping systems. However, the influence of pipe diameter on galvanic corrosion has not been investigated either theoretically or in the laboratory. We installed four galvanic couples（SUS304 stainless steel and galvanized steel）having different pipe diameters into a circulation loop in order to simulate a buildingʼs air-conditioning and other piping systems. Test results show that galvanic current increases as the pipe diameter increases, while the current density does not, which means that the anode area also increases. Moreover, because large-diameter pipes are thicker, corrosion of their pipe joints are likely to progress more slowly than the pipe joints of small-diameter pipes.