Performance of the Tin Coated Copper Tube in the Water Service System in which the Copper Plumbing Tubes have been suffering from Corrosion

摘要

The corrosion problem of the copper plumbing tubes in water is classified to cuprosolvency problem, pitting corrosion such as type I', type II and moundless, and erosion- corrosion. To solve these corrosion problems, the tin coating technique onto the inner surface of the copper tube has been successfully developed.The performance of the tin coated copper tube have been investigated under the actual service system in which the copper tubes have been suffering from pitting corrosion of type I', moundless and erosion - corrosion. The tin coated copper tubes showed the excellent corrosion resistance against pitting corrosion and erosio- corrosion. The corrosion resistances of the tin coated copper tubes were maintained due to the stable tin oxide and copper- tin intermetallic compounds. To keep the excellent type I' pitting corrosion resistance of the tin coated copper tubes, it is important to reduce the pin - holes of the tin coating. The experiences of the tin coated copper tubes have been satisfactory over 9 years without corrosion troubles. It is expected that the application of the tin coated copper tubes will solve the corrosion problem of the copper plumbing tubes.