Last update: Jan 13, 2017
Corrosion Under Insulation (CUI) is one of the most well-known phenomena in the process industries, and yet it still makes up an inordinately large percentage of global maintenance expenditures. CUI is a subject that is well-researched and understood; extensive studies have been commissioned to determine the causes, effects, prevention, and mitigation of CUI.
In the simplest terms, CUI is any type of corrosion that occurs due to moisture present on the external surface of insulated equipment. The damage/attack can be caused by one of the multiple factors, and can occur in equipment operating at ambient, low, and heated services, depending upon conditions. Moreover, CUI can occur in equipment that is in service, out of service, or in cyclic service.
The corrosion itself is most commonly galvanic, chloride, acidic, or alkaline corrosion. If undetected, the results of CUI can lead to leaks and the shutdown of a process unit or an entire facility.
Recommend changes or revisions to this definition.
November/December 2016 Inspectioneering Journal
By Adam Gardner at PinnacleART
Beyond the financial hits, undetected degradation from corrosion can also lead to critical safety risks. To effectively manage mechanical integrity, organizations need reliable methods of identifying the current states of corrosion occurring within their assets.
September/October 2016 Inspectioneering Journal
By John Reynolds at Intertek
Did you ever wonder where you fit into the entire hierarchy of a fixed equipment asset integrity management (FE-AIM) program? Or who is responsible and accountable for what aspects of FE-AIM at your site? All the way from top management down to those doing the work at the field level? That’s what I will try to address in this article.
January 19, 2015 By Nick Schmoyer at Inspectioneering
We've created a new Asset Intelligence Report titled A Primer on Corrosion Under Insulation (CUI) to get you familiarized with this widely-researched topic.
December 8, 2014
Corrosion Under Insulation (CUI) is an insidious damage mechanism that, despite being incredibly well-known and understood, still makes up an inordinately large percentage of global maintenance expenditures. CUI has been extensively researched and studied and because of that, there exist several good resources on it, and we at Inspectioneering are dedicated to bringing those resources to you.
September 15, 2014 By Nick Schmoyer at Inspectioneering
I've crunched some numbers and have come up with the three most popular damage mechanisms, based on the activity of our readers, that Inspectioneering publishes information on. I've limited the list to these three mechanisms for the sake of brevity, but keep in mind that there are nearly a hundred different damage mechanisms that affect fixed equipment mechanical integrity in the oil & gas and chemical industries.
July/August 2014 Inspectioneering Journal
By Brian J. Fitzgerald at Stress Engineering Services
As any refining or petrochemical plant manager knows, corrosion can occur on insulated piping at any facility, and is particularly difficult to prevent, track, and mitigate. Corrosion under insulation (CUI) has been a major challenge for the petrochemical and refining industries since the first pipelines were insulated with wrappings.
June 2, 2014 By John Reynolds at Intertek
Three new API standards have been published, and one has been revised and updated to a new edition. The standards are described in this post.
March 3, 2014 By Greg Alvarado at Inspectioneering Journal
The following question was posed by a member of the Inspectioneering Community: I am working in a fertilizer plant and our inspection team is very new. I was wondering if professionals in similar plants could share their knowledge related to inspection work. Please elaborate on details about the inspection function, as well as the main subjects we should focus on.
December 23, 2013 By Nick Schmoyer at Inspectioneering
Many of you are already aware of some of the changes that have occurred within API this year. For those of you who are not, here’s a quick summary.
November/December 2013 Inspectioneering Journal
By Richard Mills at GE, John T. Iman at GE Oil and Gas Measurement & Controls-Inspection Technology, and Martin Sauerschnig at GE Oil and Gas Measurement and Control
Over recent years large strides have been made in application, development, and utilization of Digital Detector Arrays (DDAs) in field radiography environments (an application previously limited to film and computed radiography [CR] techniques).
July 8, 2013 By John Reynolds at Intertek
This week’s post takes up right where last week’s post left off in our discussion on Corrosion Management and Control (CM&C) Management Systems. As I have said previously, this information is based off a series of articles I did on PEI&R MS, which you can reference here. Here are the next four...
Properly anticipating and finding the damage in your facility is no small task, and spending millions of dollars on inspection may not be getting you anywhere if it’s not the right inspection processes. PinnacleART can use industry best practice models and corrosion expertise to proactively identify damage types, locations and magnitudes so you can ensure you’re performing the right inspections at the right times. Visit us at pinnacleart.com to learn more.
July/August 2010 Inspectioneering Journal
By Santhosh Lukose at Metalcare Inspection Services Inc.
CUI (Corrosion Under Insulation) has always been a challenge for plant operators, quality assurance/reliability engineers and equipment owners. It is hard to identify the problem until it has become an emergency situation, often leading to unit shut downs or even the whole facility shut down for emergency repairs.
January/February 2005 Inspectioneering Journal
Nearly ten years ago the magnetostrictive sensor (MsS) technology was reported in this journal (July/August 1996 Issue, Volume 2 Issue 4) as a method to detect corrosion in insulated piping. At that time, the MsS Technology consisted primarily of the longitudinal guided wave mode introduced into the pipe with a coil wrapped around the steel pipe with a coil wrapped around the steel pipe and a number of large magnets setting up an axially oriented magnetic baising field in the area of the coil. The longitudinal mode worked well for dry, unfilled pipe. However, in liquid filled pipes, the longitudinal mode didn't work well because it interacts with the liquid, producing extraneous signals that, in turn, cause difficulty in analyzing data.
The goal of asset management is to effectively manage corporate assets in order to gain maximum value, profitability and returns, while safeguarding personnel, the community, and the environment. A true Asset Integrity Management program incorporates...
September/October 2004 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal
Exactly two years ago, an interview with John Nyholt appeared in the “IJ”. New ground will be covered in this interchange. We at the IJ thought it might be valuable to spend some time chatting about his background, challenges he has faced recently and what he feels are some of the biggest challenges ahead for the Inspectioneering® community.
May/June 2004 Inspectioneering Journal
By John Reynolds at Intertek
Chloride cracking of austenitic stainless steels (300 series SS) is an off-shoot of CUI, and there’s nothing really magical about it. If you have insulated solid stainless steel equipment operating in the CUI temperature range you are likely to eventually experience ECSCC.