Chemical Engineering March 2022 - 13

Newsfront
Corrosion Under Insulation
Gets Attention at CPI sites
Corrosion under insulation (CUI) remains a persistent challenge at chemical process industries
facilities, but the issue is receiving renewed attention amid a host of technologies, materials
and methodologies for detection and prevention of CUI
C
orrosion of process equipment,
piping and structural elements is
an ongoing problem at chemical
process industries (CPI) facilities
because of its potential to contribute to catastrophic
failures, safety concerns and increased
cost and effort for maintenance. The
corrosion subcategory known as corrosion
under insulation (CUI) is a particularly difficult
challenge for plants to address as industrial
sites continue to seek efficiency gains and
avoid heat loss by insulating process equipment.
By its nature, CUI is hidden from view,
and it can progress quickly under certain
circumstances. The renewed attention on
CUI has been highlighted by new coating
technologies and detection methods, aimed
specifically at the problem of CUI.
Corrosion knowledge base
Professor Homero Castenada-Lopez, the
director of the National Corrosion and Materials
Reliability Center at Texas A&M University
(College Station, Tex.; www.tamu.edu),
works with companies on improving corrosion
performance for their assets, including
testing different materials in various environments
and identifying which control actions
would be most effective at increasing safety
and reliability. " The ultimate goal is to avoid
all catastrophic incidents, " Castenada-Lopez
says, " and when you have aging infrastructure
and assets, it requires that we be
proactive, rather than reactive, at preventing
corrosion. " In part, that requires closing the
current knowledge gaps and developing a
deeper and more widespread understanding
of corrosion, " he notes.
" While most people on industrial sites
have a general awareness about corrosion's
potential impact, there remains a great need
for improving the knowledge base on corrosion,
not only for chemical engineers, but
also for mechanical engineers and others, "
says Castenada-Lopez.
IN BRIEF
CORROSION
KNOWLEDGE BASE
ISOLATED AND
AGGRESSIVE
CUI-RESISTANT
COATINGS
COATINGS AS
INSULATION
Acuren
FIGURE 1. Corrosion under insulation (CUI) is a phenomenon
that can be particularly aggressive when the presence
of moisture is combined with contaminants at a steel
surface, and so it can progress rapidly between asset
inspection intervals
Castenada-Lopez says the issue of corrosion
under insulation (CUI) has been garnering
significant focus recently, because it remains
a large problem for which there have
not generally been efficient solutions. " It's a
stubborn problem that is going to be worse
in the future, " he says.
Steven Reinstadtler, infrastructure market
manager at Covestro LLC (Pittsburgh,
Penn.; www.covestro.com) and committee
chair with the Association for Materials Protection
and Performance (AMMP; Houston;
www.ampp.org), has also seen a renewed
focus on CUI. " In the past, any solutions for
CUI were extremely limited and individual
components-based, " he says, " Now, while
CUI remains a significant problem, some
solutions are available that do address the
issue, although they tend to be complex
and involve multiple components working in
concert, and so therefore, can be somewhat
expensive, " Reinstadtler comments.
Isolated and aggressive
CUI occurs when moisture mixes with contaminants
in a " corrosion zone " between
the interior of the insulation and the coating
on the surface of the asset. " Moisture
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
MARCH 2022
13
ALLOYING
CUI DETECTION
ADVANCEMENTS
http://www.tamu.edu http://www.covestro.com http://www.ampp.org http://WWW.CHEMENGONLINE.COM
Chemical Engineering March 2022

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