Investigating the Corrosion under Insulation (CUI) on Steel Pipe Exposed to Arabian Gulf Sea Water Drops

Abstract

This paper is an endeavor to investigate an insulated mild steel pipe that exposed to three sea water drops rate (10, 30, and 50 drops/minute) at room temperature. Various experimental strategies were employed including visual inspection; scanning electron microscopy (SEM) with EDAX. After removing the insulation material, it was observed that pipes were corroded. However, the extent of corrosion was varied which was attributed to the drop rates, it was revealed that corrosion process was initiated due to water and ions penetration through the insulation, such revelation highlighted the necessity to properly examine the pipe and the insulating material. Results also revealed that severity of corrosion is proportional to the drops rates. EDAX analysis of the pipe surface and the insulating material shows the presence of difference ions including Na+, Cl-, Mg2+, Si2+ and others, the results highlighted the importance of material selection and the necessity for early detection strategy in order to avoid catastrophic failure.