The designer of industrial equipment and piping has three weapons in the fight against corrosion
under insulation (CUI). The first and primary defense against CUI is a high quality, immersion
grade coating. The second is a properly designed and installed weather barrier jacketing. The third
and, arguably, least understood element is the choice of insulation material. This paper will explore
the ways in which insulation materials influence CUI behavior, presenting results from both
laboratory and field-testing on seven industrial insulation materials and one composite system.
The materials tested were calcium silicate, expanded perlite, cellular glass, mineral wool (both
regular and water-repellent grade), and two types of flexible aerogel blanket material -Pyrogel
XT and Cryogel Z
Corrosion Under Insulation (CUI) in pipingc systems consumes a significant percent of the maintenance budget in the petrochemical industry. Prevention of CUI by the use of (1) thermal spray aluminum, (2) stainless steel pipe, (3) expanded metal cages for personnel protection instead of insulation and (4) aluminum foil wrapping are discussed in terms of long term protection, installed cost and Life cycle cost.