For more than four decades the oil & gas and petrochemical industries have had to contend with high maintenance costs, plant outages and sometimes catastrophic infrastructure failures caused by corrosion under insulation (CUI) of insulated pipes, tanks and vessels. This article highlights how coating manufacturers have done superbly well in formulating silicone high temperature-resistant coatings to protect thermally insulated critical structures from the ravages of CUI. Results are presented of CUI-simulating laboratory tests of a liquid-applied aluminium flake-filled silicone coating and a metallic thermal spray aluminium (TSA) coating. The test results have value in terms of predicting the liquid coating's real-world performance for case histories provided, namely 20 years of CUI mitigation in the oil and gas industry and 10 years of corrosion protection in mostly high temperature immersion service on oilpatch wellheads.
