QUALITY INDICATORS OF TRANSPORTED WATER AS PERFORMANCE OF CORROSION PROCESSES ON THE INNER SURFACE OF THE WATER PIPELINE

Abstract

In the presented work, the content of iron and dissolved oxygen in the transported water of the “Astrakhan-Mangyshlak” pipeline and the applicability of these indicators as measure of corrosion processes are studied. From the results of studies, it follows that the oxygen concentration in water is decreased along the length of the water pipeline. The main amount of dissolved oxygen is consumed for the processes of bio- and electrochemical corrosion of the inner surface of the water pipeline. The iron content in the source water is varied in the range of 0,1...0,5 mg/l. An increase in the concentration of iron in the transported water along the length of the water pipeline indicates corrosion processes and the removal of iron in the form of hydroxide. The distribution of the corrosion inhibitor along the length of the water pipeline was studied based on the concentration of polyphosphates in water samples and the presence and concentration of phosphoruscontaining compounds in the samples of corrosive deposits. The concentration of polyphosphates along the route of the water pipeline is decreased, due to their consumption for the formation of phosphate compounds with polycovalent cations and the formation of a protective film on the inner surface of the water pipeline. The identification of phases on the electron diffraction patterns and elemental analysis of corrosion deposits taken from template samples in different sections of the water pipeline also showed the presence of phosphoruscontaining compounds in various concentrations.