Getting Down To It: The Issue With CUI.

Corrosion Under Insulation (CUI) is one of the most well-known problems a multitude of industries face, yet it still makes up a staggeringly large proportion of global maintenance expenditures. CUI is a subject that is well-researched and understood yet the issue persists. With extensive studies being commissioned to determine the causes, effects, prevention, mitigation and repair of CUI what is the best approach to combat it, and what is the most efficient route to take once it’s time for those inevitable repairs? Well to answer these questions, first we must understand the basics of CUI.

What is CUI?

In the simplest of terms, corrosion under insulation (CUI) is any type of corrosion that occurs due to a moisture buildup on the external surface of insulated equipment. The damage caused can stem from one or multiple factors, and can occur in equipment operating at ambient, low, and heated temperatures, in wet or dry environments. Depending upon conditions and the material itself the corrosion can commonly fall under terms known as galvanic, chloride, acidic, or alkaline corrosion. Moreover, CUI can occur in equipment that is in service, out of service, or in cyclic service.

So understanding that, you can see why CUI is one of the most difficult processes to prevent. The reason for that is, for the most part, no matter the precautions taken, water invariably seeps into the insulation and begins its dirty work sometimes unseen until process leakage occurs. Add in variable temperatures, environmental conditions and the make up of the metal itself and these factors can create a breeding ground for CUI.

If undetected, the results of CUI can be devastating, leading to the shutdown of a process unit, an entire facility and in rare cases an unfortunate safety incident.

Sub-par outcomes can also result from hiring contractors who don’t stand behind their work. Therefore, partnering with a provider who offers a service guarantee is incredibly important. It not only serves as an incentive for providers to use the best technology but also to send the most highly skilled technicians to ensure work is done correctly the first time. And, if these technicians happen to make an honest mistake, the guarantee means they’ll provide leak repair re-injection services at no additional cost.

How Do You Find Corrosion Under Insulation?

The most common standard practice in today’s industry is for the scheduled stripping and removal of the insulation, performing a visual assessment and then, combined with NDE methods, they determine the presence and extent of corrosion. There are a wide variety of techniques to test for CUI from Eddy Current to X-ray, Remote TV monitoring is an option and even Electro-magnetic devices, so what’s Innovator’s approach to tackling CUI?

What’s great about Innovator’s method is that it eliminates the “guess work” when it comes to identifying CUI. We achieve this is by utilizing a screening tool to detect wall loss through the insulation, we can then identify CUI without the need to remove insulation. The technology behind Innovator’s CUI bracelet is an electromagnetic method of NDT known as RFT (Remote Field Testing). The bracelet clamps around the curvature of the pipe (insulation) and is hand guided by a technician at a speed of 2”/ sec. Each scan covers a 9” section at a depth of up to 3” of insulation, using multiple runs on larger diameter pipe. The bracelet also has the capability to extend out to a flat position for scanning large diameter vessels and flat surfaces, showing the versatility of the process.

How Much Can CUI Cost Me?

Well, that depends… According to NACE International, an industry authority for corrosion control solutions, estimates yearly global expenditure on corrosion to be 2.5 trillion dollars US, to put that in perspective that’s equivalent to roughly 3.4 percent of the global Gross Domestic Product (GDP). That may sound staggering, but it’s the tip of the iceberg, on top of the global expenditure there are countless manhours lost, safety incidents and shut downs all stemming from corrosion.

But that’s where we come in; a rough estimate of our cost effectiveness ratio as compared to the industry standard method would be 90%/10%. What that means is we can finish the job 90% faster, for just 10% of the cost, we can achieve this efficiency all while simultaneously maintaining the highest of safety standards.

Partnering With Innovator for CUI

Merging cutting edge technology with the proven Innovator method, we are the leading experts on the detection and repair of CUI. Additionally, with on staff certified rope access technicians, we can handle the process from start to finish, regardless of location.


Capable, cross-trained Innovator crews can bring diverse expertise, cutting-edge technology, and creative solutions to you and your company. Learn how: Contact us by email at, by phone at (855) 436-4666, or on our website.