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The purpose of this paper is to implement the corrosion protection method for steel pipes used in a municipal water-pipe network. Results of an inhibitor protection system installed on the system are presented. Inhibitor protection was required due to the high corrosivity of the water collected by a surface intake, which had resulted in a large number of failures and low water quality, due to the presence of corrosion products.

To assess the effectiveness of protection and to control the optimum dose of the inhibitor dispensed, an automatic system of corrosion monitoring was used, together with an assessment of water corrosiveness based on measurements of physical and chemical properties of water.

Calcium polyphosphate, in the role of a non-toxic corrosion inhibitor, showed significant effectiveness as a anticorrosive and its results were fully noticeable after several years following the commencement of protection. Corrosion monitoring has shown that the effectiveness of inhibitor protection is highest in the summer season, when the water is characterised as being in its most corrosive form.

A reduction in the corrosion rate improves the quality of water and its chemical parameters fall within the standard range for water intended for consumption. The corrosion inhibitor action accelerates the formation of a layer limiting the corrosion rate. In this case, stable corrosion rates may be obtained after only the first year. In terms of the designing systems for monitoring corrosion in water systems, this is very important information as reliable results can be obtained for a long period after the launch of the system.