Internal corrosion-protection of galvanized-steel piping - in water systems, by passivation using phosphoric acid to remove galvanized layer and coating with resin

摘要

The protection comprises H3PO4 passivation of the inner walls of the pipes in situ, and replacing the galvanized layer, removed by the passivation treatment, by a film, or films, of synthetic resin. Pipework already corroded is pre-cleaned with, e.g., citric acid, either alone or mixed with the H3PO4.