CUI is a major challenge for oil and gas and petrochemical industries, and Armacell offers one of the best insulation solutions to mitigate corrosion under insulation

Corrosion is formed when water is trapped between the surface of the metal pipe 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 deg C and 175 deg C, and is particularly critical above 50 deg C.

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.

CUI continues to be a major issue for process industries in oil, gas, chemical and power generation sectors. It is estimated that up to 10 per cent of annual maintenance costs in these industries are caused by CUI. Severe cases of CUI may put the safety of personnel, operation processes, environment, and reputation at risk.

Thus the choice of insulation system is a critical factor for effective mitigation of CUI. Armacell Energy offers two different kinds of industrial insulation materials which are applied directly to the pipe or equipment surface in industrial projects:

• ArmaFlex® Industrial Grade is flexible elastomeric foam (FEF) based on synthetic rubber with foamed closed cell structure.

• ArmaGel™ is an aerogel (AG) blanket, hydrophobic, with fibrous open structure, high maximum service temperature and low thermal conductivity.

ArmaFlex Industrial and ArmaGel have been tested in respect to their CUI mitigation properties in salt-water spray and high humidity tests by TNO/Endures and InnCoa institutes, respectively. Both ArmaGel and ArmaFlex offers effective resistance to water ingress, minimising the onset and spread of CUI, proven by a rigorous six-month corrosion assessment.

REFERENCES:
 
• NACE impact study, 2016, Annex D, pg D-10.

• https://local.armacell.com/en/energy/problems-we-solve/corrosion-under-insulation-cui/