Corrosion of the fins leading to blocking of the airside flow in air cooled heat exchangers is one of the biggest problems in their operation and maintenance.

As air passes over the lower rows of finned tubes it is heated, and corrosive deposits of the salts in solution form on the fins themselves. Along with the salts, the air also carries dirt and dust and possibly small concentrations of chemicals.

Blocked and fouled fins considerably reduce the heat exchanging efficiency of the tubes. Sister companies Tube Supply International Ltd and Overcoat Finishing Ltd have recently installed new plant in their UK works capable of applying an Electrophoretic coating to closely pitched fins (11fins / inch or closer) on tubes of up to 40 ft long.

The Electrophoretic process ensures that an even coating of a chemically resistant paint completely covers the finned and bare tube outer surfaces, even down to the fin base. This chemically resistant paint (PPG Paint) has a very smooth external surface to which neither the fouling layer nor the salts from evaporation adhere, resulting in the life of the external fins being extended by 3-5 times when compared with the life of a unit without coating.