Analysis of steel structure corrosion of drinking water distribution system in family indoor environment

Abstract

In this paper, corrosion investigation and analysis of steel structure of drinking water distribution system in a family kitchen have been carried out. Results indicate that galvanized corrosion and condensation corrosion under thin water layer have been found the main corrosion type. XRD analysis shows that the rust layer is composed of α‐FeOOH, γ‐FeOOH and Fe3O4. For preventing galvanic corrosion, using non‐conductive materials between metals of different electropotential, i.e. electrically insulating the two metals from each other has been recommended. For preventing condensation corrosion under thin water layer, cleaning the pipe external surface to minimize the condensation corrosion is necessary and a good epoxy coating on the pipe external surface may also work. The selection of PVC pipe with better quality and no leaching of inorganic pollutants into water is also a good choice, however, in this condition strong hitting to the PVC pipe should be avoided.