Inspection of internal erosion-corrosion of elbow pipe in the desalination station

Abstract

Due to the worldwide decrease in the quantity of potable water in the last decade, the desalination station is among one of the most important methods to treat seawater to supply the dry regions, Sahara regions and the offshore regions with purified water. During the desalination process, many problems can appear including the corrosion problems that attribute to the materials of piping systems and theirs geometrical shapes, and the chemical composition of water taking into account the conditions of transporting. Pipe elbow is one of the necessary parts to build the integrated piping system which is considered as a linking point between different parts of the transport systems. Because of its effective role and complex forms that based mainly on welding processes, the pipe elbow is vulnerable to corrosion problems considering the liquid nature of the effluent, and the surrounding pressure and temperature. The results of the mechanical characterizations tests such as metallurgical examinations using optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) allowed us to analyze the main causes of the defect in this part. The obtained results showed that many technical solutions can be employed to mitigate and relief the encountered internal corrosion in pipe elbow, which helps greatly in enhancing the energy development in desalination industry.