CUI remains one of the most challenging integrity threats in industrial plants. Hidden beneath insulation, it often develops unnoticed until failures, leaks, or costly shutdowns occur.
What’s often underestimated is that CUI is not only a materials problem – it’s a design problem.
When moisture becomes trapped between insulation and steel, temperature cycling and condensation dramatically increase time of wetness, accelerating corrosion even in moderate environments. That’s why spacer-based (non-contact) insulation systems are gaining attention. By introducing a controlled air gap, these systems:
- Promote drainage and faster drying
- Reduce moisture retention
- Significantly lower corrosion rates under insulation
This approach is supported by industry guidelines such as CINI, NORSOK M-004, and NACE SP0198, and validated through laboratory testing (ASTM G189-07).
Reducing time of wetness is one of the most effective ways to reduce CUI risk.
Good coatings matter. Good insulation matters. But good design often makes the biggest difference.
What’s your experience and best know how regarding CUI and mitigation?