Looking under the Covers for Corrosion Under Insulation (CUI) with the C-arm

From food processing to refineries, 60 – 80% of pipe maintenance costs have been attributed to Corrosion Under Insulation (CUI, see Brian J. Fitzgerald et al, Strategies to Prevent Corrosion Under Insulation in Petrochemical Industry Piping, NACE-03029, CORROSION 2003). One tool that we use in our CUI combat is the C-arm radiographic system (also called RTR, or real time radiography). Without removing insulation, this low power x-ray system allows the technician to look at the outside surface of a pipe and small diameter vessels, through cladding and through insulation. IRISNDT uses these key systems throughout the USA refineries. The video above shows the C-arm system inspecting pipe; it starts with video and then switches to a real time radiographic image of the pipe. The rust trapped between the pipe and the insulation is the CUI that we hunt for.