Corrosion Under Insulation (CUI)

Corrosion under insulation is a severe form of localized external corrosion that occurs in carbon and low alloy steel equipment that has been insulated. This form of corrosion occurs when water is absorbed by or collected in the insulation. The equipment begins to corrode as it is exposed to water and oxygen. This results in loss of wall thickness, pitting and crevice corrosion.