Failure of titanium condenser tube

Failure investigation was carried out on a titanium condenser tube that suffered from a large size perforation. The environment at the shell side is hydrocarbon with low pressure steam, while it is seawater at the tube side. The tube was totally plugged with alkaline scale, consisting of calcium carbonate and calcium sulfate. The investigation revealed that in the initial stages of fouling, the titanium tube suffered from erosion–corrosion damage due to the presence of turbulent flow conditions and suspended solids. On the other hand, when the tube became totally fouled, overheating occurred, leading to growth of the oxide film on the internal tube surface. However, the titanium oxide film cracked due to the pressure exerted by the growing scale inside the tube, leading to thin lip rupture.