Design of a High Solids Epoxy for Corrosion Under Insulation (CUI) Prevention

Abstract Corrosion Under Insulation (CUI) is widely acknowledged to be a critical issue facing plant operators in the oil, gas and chemical industries. CUI accounts for approximately 10% of the total maintenance budget is spent repairing damage from CUI, mainly on pipes. The risk of CUI is considered high in the temperature range 50 – 175°C (122 – 347°F). Periodic inspection remains the best way to prevent CUI failures but is costly and time consuming. Many failures might still not be captured even with a reliable inspection scheme and in this regard improvements which can improve the protection offered by the organic coating system used on the steel surface and under the insulation can be extremely beneficial. A new high solids epoxy coating system has been designed to help prevent CUI. Test results will be shown for relevant CUI tests for this high solid epoxy and a performance comparison with a traditional phenolic epoxy is done. The high solid epoxy has also been tested for maintenance service where surface preparation is often less than ideal and the steel surface is still hot as processes are not shut down for maintenance.