The Influence of Water Quality Change on the Corrosion Process in Galvanized Pipes of Fire Protection Installations
Małgorzata Wojtkowska, Agnieszka Malesińska, Agnieszka Machowska, Pierfabrizio Puntorieri, Giuseppe Barbaro, Vincenzo Fiamma, Stanisław Biedugnis
The article presents the results of an investigation of water composition and quality in sprinkler installations, as well as the influence of temperature changes on the corrosion process. The physical and chemical components of the water were measured to ascertain the influence of its properties on the corrosion process in a wet pipe sprinkler system operating in significantly changing ambient temperature conditions. The article presents the results of measurements of the wall thickness of galvanized pipes and changes in the chemical composition of water occurring under the influence of variable ambient temperature. The range and variability of temperatures corresponded to the seasons of the year: spring and summer in a temperate climate. Changes in the corrosive aggressiveness of water were assessed using the Langelier saturation index (LSI), the Ryznar stability index (RSI), and the general acidity intensity index (I). The tests revealed that the tap water used demonstrated strong corrosive properties for galvanized pipes. The calculated indices showed the tendency of water to cause corrosion (−1.1 > LSI < 1.0; RSI = 7.1–12.8). The chemical parameters that significantly influenced the corrosion of galvanized pipes are chloride (Cl−), sulphate (SO42−), and bicarbonate (HCO3−) ions. An important factor contributing to the intensification of corrosion is the roughness and heterogeneity of the pipe surface.