...Clay D. Rodery A large process tower in a petroleum refinery was discovered to have severe corrosion under insulation (CUI) in two areas. The areas were confined to the vicinity of external rings, but spanned 360 deg of the tower. The remaining thickness of the shell in these areas ranged from 3 mm...

..., or penetration power. The possibility of inspection under insulation, coatings, or with water filled pipes or around elbows is possible. Detection of defects beyond a pipe elbow is difficult for axisymmetric wave impingement onto the elbow. For nonaxisymmetric input to the elbow region, however, via partial...