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摘要

A process of making tubes of copper or copper-alloy for resistance to pin-hole corrosion caused by water or water carrying chemically aggressive constituents. The process comprises successive steps of an oxidation heat treatment to a strip of copper or copper-alley to achieve a carbon content reduction to a predetermined value, followed by surface cleaning treatment to remove loose, non-adhering deposits and finally welding the strip to make a tube with the cleaned surface forming the interior of the tube. The tubes have particular application for use in pipework installations of condensers and heat exchangers.