Installation pipe made of copper with an inner surface of tin oxide and process for coating same

摘要

The invention relates to an installation pipe made of copper with an inner, uniformly adhering surface of tin oxide having a layer thickness of between 0.05 mu m and 0.5 mu m and a diffusion interlayer of copper/tin-alpha-monophase having a layer thickness within the range from 5 mu m to 20 mu m and to a process for coating the installation pipes. The process comprises essentially the steps of chemical tinning of the inner surface of the copper pipe, subsequent diffusion annealing of the copper pipe under inert atmosphere to create a copper/tin-alpha-monophase on the inner surface of the tube, followed by an oxidising thermal inner surface treatment with a gas mixture to create a surface composed of tin oxide. The layer of tin oxide ensures high-grade, consistent and long-term protection against a release of copper ions into the drinking water.