Flow-Accelerated Corrosion (FAC) or Erosions-Corrosion remains a common cause of failure in HRSGs and conventional boilers, yet the underlying causes and solutions have been well understood for more than 25 years. The two factors influencing the susceptibility to FAC are: a) Unit Design and b) Process Conditions. It is important to know how FAC-prone your HRSG or boiler design are, this will help you optimise your operating conditions to suit that design.
When assessing design factors, the primary question is whether the HRSG/boiler tubes and pipes' geometries and materials are suited to their flow profiles across the range of operating load cases. Operational factors are primarily concerned with assuring good control of water chemistry parameters (pH, dissolved oxygen or ORP, iron levels).