Cold-and hot-water supply copper-alloy pipe with inner-surface protective film, method for manufacturing same, and hot-water supply heat exchanger

摘要

A cold- and hot-water supply copper alloy pipe with an inner- surface protective film is provided. A pipe body is made of a copper alloy which consists essentially of at least one of Zn and Mn by 0.02 wt % or more as the total amount, Zn being restricted to 5 wt % or less and Mn being restricted to 3 wt % or less and balance being copper and inevitable impurities. A protective film is formed on the inner surface of the copper alloy pipe body and made of Sn and inevitable impurities. The protective film has an average thickness of 0.2 to 4 &mgr;m in the pipe circumferential direction. The protective film can be made of Sn, an intermetallic compound of Sn and Cu, and inevitable impurities or made of an intermetallic compound of Sn an Cu and inevitable impurities. In any case, Cu.sub.3 Sn must not present on the surface of the protective film. This type of copper alloy pipe makes it possible to prevent an &egr; phase which causes pitting from forming on the surface of the protective film, prevent copper ions from being eluted, and improve the pitting resistance.