Failure of heat exchanger tubes is a common problem in the oil and gas as well as petrochemical industry across the world. Cooling water corrosion and fouling are closely related and should be analyzed together. Fluid temperature, type of water, type of cooling system, oxygen content and fluid velocities are the critical factors contributing to these damage mechanisms. In this study, the effects of flow velocity in the cooling water service to the corrosion rate were analyzed and the risk assessment was conducted using the risk-based inspection (RBI) principal. A condenser type heat exchanger used to cool water at the bundle/tubes side was chosen as a case study. The results showed that the flow velocity in the cooling water system gave a great effect on the corrosion rate, and ultimately affecting the risk category. Higher corrosion rate was seen at the minimum flow velocity. © 2006-2018 Asian Research Publishing Network (ARPN).