Mapping Corrosion Under Insulation (CUI)
This project with InspecTerra’s Norway branch took place at Equinor's processing plant and testing facility in Kårstø, Norway. The work included scanning the bottom section of a large insulated separator vessel using InspecTerra's novel iCAMM technology. The vessel was manufactured from ASTM A 516 Gr.60 steel, with 16 mm nominal wall thickness. The vessel was insulated by approximately 75 mm thick foamglass insulation, and covered by aluminum cladding and strapping.
The 1 m x 1.4 m test area in the bottom section of the large insulated separator vessel.
Aluminum cladding and 75 mm thick insulation.
Because iCAMM technology does not require any special surface preparation and is not impacted by any non-ferromagnetic covers (e.g., paint, coatings, insulation, cladding, etc.), the condition of the steel vessel was scanned directly through the aluminum cladding and thick layer of insulation.
The 1 m x 1.4 m test area was scanned in multiple passes in less than 1 hour. The normal scanning speed for the iCAMM tool is approximately 1 to 2 metres/minute, depending on the application.
The resulting corrosion map clearly identified the critical areas of corrosion in the test area. The impact of welding is also visible in the results, as the welding process significantly alters the magnetic field of the object.
This application demonstrated how iCAMM technology can be used to map corrosion under surface cover (e.g., cladding and insulation) quickly and effectively, which can then be used to guide more detailed examinations (e.g., using UT), thereby saving inspection time and cost, and increasing confidence in the results (i.e., by identifying all critical/maximum areas of corrosion without the need to remove the insulation).
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