Metal substrates in chlorine-containing environments
The chlorine-based chemicals used in water treatment produce chloramines due to a
reaction with nitrogen-containing compounds.
Chloramines are very volatile and are released into the surrounding environment in both indoor and outdoor climates where they are deposited on metal surfaces, where they break down and form corrosive compounds.
Repeated cycles of condensation followed by evaporation cause accumulation of these aggressive chloride-containing compounds on metal-based substrate surfaces under exposure to oxygen.
These compounds pose significant metal corrosion problems in any chlorine-containing environment, be it work purposes that include chlorine treatment such as in water treatment plants or in swimming facilities.
In public swimming pools, the presence of chlorinated water can lead to very aggressive corrosion which is largely not visible during normal inspection routines, due to large room volumes with significant ceiling heights that require extensive access equipment for inspection access.
NAST carries out extensive laboratory testing in an artificial chlorine chamber as well as parallel field tests in selected environments.
With a significant focus on increased barrier strength of Electrogalvanized Zinc using high quality nanotechnology, tests carried out show a selection of electrogalvanized fastening devices for HVAC systems where galvanization constitutes a coating thickness of 10-12 mμ.
