Corrosion Under Insulation: What You Need to Know
Wednesday, February 17, 2021

Corrosion Under Insulation: What You Need to Know

Is CUI eating your lunch and your pipes?

Are you staying on top of the fight against CUI? Each year, Corrosion Under Insulation (CUI) goes undetected on pipe, towers, storage tanks and vessels, leading to millions of dollars worth of damage when inevitable failures and breakages occur. As one of the most pervasive and difficult issues facing today’s process piping, CUI presents an immense amount of risk both from a safety and financial aspect if left undetected. Thankfully, using tools like Russell NDE’s bracelet probe and Eddy Current technology, getting an accurate view of the state of your pipes makes it easy to detect early signs of corrosion and stop the spread before extensive damage has the chance to set in. Below, we’ll explore some of the biggest risk factors for CUI, as well as provide a brief overview as to how both our bracelet probe and eddy current technology work. Read on to learn more

What Causes CUI

Corrosion under insulation is caused when moisture or condensation manages to find its way under the barrier of your pipe’s insulation. If this contact is not detected early on, the moisture will remain in place and begin to slowly degrade the integrity of your pipe’s structure, leading to eventual holes or breaks forming. While there are many elements that can leave pipes at risk for moisture exposure, the main factors to be aware of are:

  • Hot or humid environments
  • Climates prone to sudden weather shifts
  • Areas with heavy snow or rainfall
  • Any atmosphere that encourages sweating or contains chlorides or sulphides.

Ultimately, any environment that promotes a consistently humid or moisture heavy atmosphere can lead to significant problems where CUI is concerned if you do not have the proper inspection protocols in place. By using NDT technology and the methods described below, you can help to reduce the chances of CUI going undetected in the long term.

Prevent to Protect

By far, the number one way to prevent the issues caused by corrosion under insulation is to stop it before it has a chance to worsen. Russell NDE is a world-leading manufacturer of NDT technology, including the Russell Bracelet Probe, and our eddy current using Ferroscope 308 RFT/ECT system. The bracelet probe is adaptable to insulated pipes starting at 4” and contains detectors that cover a 10” wide scan path to detect external pitting or corrosion. The probe uses a specialized electromagnetic induction technique to provide comprehensive inspections on insulation up to 125 mm thick and is extremely accurate in terms of allowing you to identify key sources of corrosion, as well as its progression.

Our flagship Ferroscope Instrument uses eddy current technology as opposed to electromagnetic pulses and relies on a modified form of RFT to conduct assessments. While this model of bracelet probe is best suited for identifying CUI on insulated pipes and vessels, a different model of Bracelet Probe can inspect coated or bare pipe for internal corrosion.

Need help finding the right fit for your application? Russell NDE is here to assist. Contact our team today to learn more about CUI inspection as well as routine pipeline evaluation.


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