Traditionally, closed system treatment programs have involved adding corrosion inhibitor and
periodically testing for the residual. To be effective, these treatment programs must also
include cleaning. This paper will discuss the various aspects that should be evaluated as part of a closed system treatment program.
If the iron concentration in an alkaline chelant boiler cleaning solution reaches a high value when dissolving magnetite, it sometimes continues to increase rapidly and not level, indicating corrosion of the boiler metal. A laboratory study of “runaway iron increases” investigated the cause and the best mitigation methods.