Development of a Procedure to Prevent Dezincification of Brass Components in Drinking Water Installations

摘要

Researchers at Institut fuer Korrosionsschutz Dresden GmbH (short: IKS) aim to develop a procedure to analyse corrosion resistance of novel lead-free dezincification resistant brass alloys according to DIN EN 15664-1 in contact with several less and highly corrosive drinking waters. Within the project each of two lead-free brass alloys and one common leaded brass are tested at different synthetically adjusted concentration levels (chloride, sulphate, K_(s4.3). First a complex pilot plant according to DIN EN 15664-1 was installed, containing three separate facilities, each with four test pipes. Ten of the resulting forty test points can be examined simultaneously in this pilot plant. Therefore several test rounds are necessary, each running for eight months. During the experiments metal migration is measured in order to assess the compliance with the limits of the German Drinking Water Ordinance (TrinkwV 2001). Furthermore, depths of corrosive attacks of the test specimens are measured after each test run. As a result of the research project a comprehensive data pool will be obtained by combining hygienic and metallographic analysis of test specimens. This can serve as a basis for the development of a tool comparable to the Turner diagram, defining critical water qualities for the tested materials concerning metal migration and corrosion.