Corrosion under Insulation (CUI) is a threat to many industries in a wide sense. If neglected, the corrosion process is mostly well hidden under the insulation system and becomes only obvious due to severe integrity failures.
CUI occurs through penetration of water, moisture and contamination via:
- Condensation (batch mode, pipes in the open → dew point during night)
- External sources (rain, sprinkler system)
Unlike other corrosion threats, inspection becomes the only barrier to CUI failure – a job that inspection was never intended for. Furthermore, CUI can be very localised. In other words, most of the equipment remains in good condition, which is why sample inspection is unlikely to give you the assurance you need. Highly reliable inspection is needed which to date is still costly periodic removal and reinstatement of insulation.