Pigmented Antifouling Coatings for Improved on-Site Inspection

Abstract

Sol-gel derived antifouling coatings for use in crude oil heat exchangers have been successfully utilized for years. The combination of a very thin and heat conductive coating with low surface energy and low surface roughness in an inert glass ceramic matrix has proven very effective in preventing fouling accumulation and maintaining sustained production. A challenge using very thin and transparent sol-gel coatings is reassuring that the items are actually coated and are correctly applied. For plate heat exchangers, that may only be single side coated, it is important that the unit is assembled correctly, so that the coated side of the heat exchanger plates face the crude oil. Also, for inspection purposes and for estimation of residual lifetime, it is important to be able to establish the quality of the coating efficiently and quickly – also inside individual tubes of a shell and tube heat exchanger. Here we present ongoing coating development of Thermo Coat 200 (TC200), an antifouling coating stable up to 300 °C/572 °F, which is provided with inert and heat stable pigments that allow quick inspection of coating integrity, both before and after operation. Together with procedures for testing coating repellency and substrate adhesion, the pigmented TC200 coating may facilitate the industrial transition to antifouling coatings.