There are 4 main reasons that cause corrosion in heat exchangers to need to be concerned during the inspection: Water impingement, Temperature, Vibration, Velocity.
Refer to: Corrosion in Heat Exchanger
Likely Location of Corrosion – Heat Exchanger Tubes at Baffle;
Heat Exchanger Tubes in the Baffle Plates area are highly prone to corrosion. Due to the possibility of vibration of the Tubes causing friction with the Baffle (Vibration fretting) or Erosion from Fluid flow in Heat Exchanger
For smaller tubes, The corrosion of the Tubes on the Baffle can be checked using a hammer. If the Tubes in the Baffle area is thin or corroded, when we knock, Tubes bounce or shake occurs.
Likely Location of Corrosion – Heat Exchanger Tubes at Shell Inlet Nozzle (1);
Tubes on the opposite Inlet Nozzle of Shell is another area where the Heat Exchanger Tube Bundles are likely to be highly corrosive. Since it is the area where Fluid Flow comes directly, causing Erosion in this area.
Therefore, when checking the Tube Bundles, don’t forget to check this area especially. Especially in the case of the Tube Bundles no Impingement Plate and Shell Inlet Fluid looks to the Two-phase.
Shell and Tube Heat Exchanger – Impingement Plate
Impingement Plate discs Plate is brought to the Tube Bundle exactly the opposite Shell Inlet Nozzle to help spread Inlet Fluid Flow and prevents Tubes corrosion (Erosion, Cavitation) and Vibration by Impingement Plate serves to prevent.
Likely Location of Corrosion – Heat Exchanger Shell adjacent to Impingement Plate:
For Shell and Tube Heat Exchanger which have a high velocity of Inlet Flow on Shell Side and Impingement Plate, another area that has a high chance of Erosion corrosion is Shell. The part near Inlet impingement plates is because when Inlet flow collides with Impingement plate may reflect or deviate to collide with Shell.