Introduction Flow accelerated corrosion (FAC), also termed flow assisted corrosion, is a phenomenon wherein carbon steel components with a protective film oxide degrade over time. FAC occurs only when the fluid is moving (not static), when it contains water, and is unsaturated in iron. It is imperative to understand FAC since it is different from simple erosion — the mechanisms of these two processes are different. In short, FAC does not require particle impingement, cavitati