This paper will discuss issues related to corrosion protection of high temperature carbon steel substrates which are insulated to preserve energy, provide process control and to keep workers safe from burn injuries. Corrosion under insulation (CUI) is a serious problem for many owners who have insulated service, where severe corrosion often occurs which can cause plant or process shutdowns, environmental damages and potential injuries to workers.
A review of past and current technologies for preventing CUI will be presented. The initial and long term costs, performance characteristics, expected service life as well as ease of application and repair of coatings used under insulation will be discussed. Field and laboratory performance experience obtained from users, thirdparty laboratories, and vendors of the various coating systems are used for this comparison.