Anticorrosion protection of industrial or drinking water pipes - by magnesium hydroxide gel from extraneous current applied to magnesium anode

摘要

A protective anti-corrosion layer in pipes and fittings used in industrial and drinking water systems is produced by passing the water through a tank with a magnesium anode. An extraneous current supply, connected to the anode, produces a magnesium hydroxide gel which becomes deposited on the inner walls of the following galvanised iron or copper pipes. Magnesium is always present in water; it avoids the undesirable presence of aluminium ions, caused by aluminium anodes. Zinc ions are also undesirable in drinking water. The new system protects copper pipes where even phosphatising does not prevent corrosion.