Forensic Engineering

Coating Deficiencies

Background

During visual inspection, high grade of corrosion was observed in the interconnection between the baffle plate and the condenser hotwell tank, along with moderately high levels of flash rusting in the tubes sheet.

Analysis

Though the high level of flash rusting is not a concern for the integrity of the condenser, as it appears to be evenly distributed and in the early stages of corrosion, it is however the cause of rust creep and scales build-up at the interface with the hotwell tank.

On the other hand, deficiencies in the coating application and accumulation of the paint film created surface stress, lack of flexibility and microcrackings in the coating which combined with excess of flash rust led the condenser to failure.

This problem can be solved installing rubber gasket in the interface between the hotwell and the tube-sheet.

Conclusions

This problem can be solved installing rubber gasket in the interface between the hotwell and the tube-sheet to solve materials incompatibility and verify the chemistry cycle to avoid flash rust (check O2 content and corrosion inhibitor compatibility).

coating