At what temperature range is CUI a concern for insulated carbon steel vessels?

The concern for Corrosion Under Insulation (CUI) in insulated carbon steel vessels primarily arises in the temperature range of 10-350°F. Within this range, moisture can accumulate beneath the insulation material, creating an environment where corrosion can occur.

At temperatures below 10°F, the likelihood of condensation is reduced, as the temperatures are generally not conducive to moisture formation under insulation. Similarly, while temperatures above 350°F can lead to insulation breakdown and other types of corrosion mechanisms, CUI specifically is most prevalent in the 10-350°F range, where the combination of moisture and suitable temperatures allows for corrosion processes to initiate and progress.

Understanding this temperature range is critical for maintenance and inspection planning, ensuring that appropriate preventative measures are taken to mitigate the effects of CUI on carbon steel vessels.