Corrosion resistance of commonly used plumbing materials for water distribution systems exposed to disinfection treatments

In this study, the corrosion resistance of commonly used plumbing materials was evaluated when three disinfection treatments were applied in hot water distribution systems. In particular copper, brass, stainless steel and galvanised steel were tested in environments containing monochloramine, chlorine dioxide and hydrogen peroxide disinfectants under real field conditions for a long period of time (1 year), in order to evaluate the effect of free corrosion on the metal specimens; chlorinated polyvinylchloride (CPVC) was tested in the same environments in order to evaluate the degradation of the mechanical properties of plastic specimens. The results obtained enabled us to rank the metallic materials corrosion resistance against disinfectants in decreasing order, as follows: stainless steel, copper and copper-based alloys, galvanised steel. CPVC samples proved to be extremely stable in all of the disinfectants investigated, maintaining the same compression behaviour of the pipes aged with untreated water after 12 months of exposure.