Corrosion under insulation
This is an insidious problem is often noticed only when extensive damage has already happened. Corrosion under insulation accounts for 10 percent of total maintenance budgets and is the reason for more unplanned downtime as compared to all other causes.
Corrosion occurs due to trapped moisture
Corrosion is formed when water is trapped between the surface of the metal pipe or duct and the insulation material. Termed corrosion under insulation (CUI), this insidious problem is often noticed only when extensive damage has already happened. CUI usually occurs on pipes with a line temperature between 0 °C (32 °F) and 175 °C (347 °F) and is particularly critical above 50 °C (122 °F). The risk increases on equipment which is operated discontinuously or at dual temperatures. If the temperature fluctuates, condensation can form in the insulation material and water can reach the surface of the pipes.
Damp insulation promotes corrosion
When moisture penetrates the insulation material through a damaged covering or in the form of water vapour transmission. the insulation material gets wet. This affects the insulation properties and results in energy losses. It could also lead to corrosion on the pipe surface.
