By Gianni Mattioli, Mattioli
During the installation of a new section of their sewage grit and screen filter system at Melbourne Water’s Eastern Treatment Plant, a major future corrosion issue was identified. The articulation joint between the new sections were comprised of two at risk substrate materials; steel and concrete. Each needed a protective coating to shield them from hydrogen sulphide gas and other sulphur containing corrosive materials found in sewage.
Melbourne Water engaged Mattioli to develop a solution to protect each substrate with the one coating system that had to be applied within a strict six hour window of opportunity. After reviewing a number of products not one product could be identified that would protect the various substrates at once using the above criteria. The additional challenge was that the stainless steel section of the joint had to be uncoated to allow free movement so a coating would have to be fixed to the HDPE as an anchor between the two.