CUI and Touch Point Corrosion: There are No Silver Bullets - Spring 2019 "Meeting of the Minds"

*As seen in Inspectioneering Journal’s May/June 2019 issue.

Inspectioneering and Pinnacle hosted their most recent ‘Meeting of the Minds’ roundtable discussion in San Antonio, Texas this May. The meeting, in which a small group of leading mechanical integrity subject matter experts gathered over dinner, explored several pertinent topics focusing on how owners extract value out of their mechanical integrity programs.

Readers may recall from our Recap of the Fall 2018 Meeting of the Minds that the discussion centered around risk-based inspection and the value it brings to sites. This time around, participants discussed numerous different themes ranging from corrosion under insulation (CUI) programs, to integration of integrity operating windows (IOWs), and corrosion control documents (CCDs), to getting the most out of internal site assessments.

This article will focus on the two topics that consumed the majority of the conversation: how sites are managing corrosion under insulation and corrosion under pipe supports (also referred to as touch point corrosion). Below is a quick recap of the questions that were asked, as well as some of the key takeaways.

Are sites’ CUI programs baked into routine inspections or designated as special emphasis programs?

Most participants agreed that, due to the additional resources needed for CUI programs, special emphasis programs are a must. CUI is so pervasive, problematic, and costly that special attention needs to be paid to the program and it should be represented by a separate line item in a plant’s budget. One participant added that each of their CUI programs were initially funded at the corporate level, but they are now each owned and managed by the inspection/maintenance group at the facility level.

How do you justify the cost of your CUI program to plant management?

One participant, coming from an upstream background, presented the following scenario: if an offshore platform goes down for a day, that equates to millions of dollars in lost profit opportunity. Furthermore, due to the isolated nature of offshore facilities, one single leak in a critical system can very easily upset the entire process and, at worst, find its way into the news. One CUI finding could be enough to justify the whole campaign for an entire fleet.

Another participant remarked that “the perception may be that millions of dollars were ‘wasted’ [on a CUI program] because there weren’t many findings, but the reality is that you’ve gained a lot of certainty because you’ve stripped insulation, inspected, made repairs, and recoated the piping.”

And what if the manager doesn’t buy into that? “You go above the manager.”

What technologies, techniques, and strategies have proven the most effective within your CUI program?

Numerous ideas were mentioned with varying levels of success. Some of these ideas include:

• Rope access in lieu of scaffolding for inspection, painting, and insulation work. Assuming one’s jurisdiction is accepting of the practice, rope access should require less time and resources than scaffolding.
• Aerogel as a replacement for traditional insulation. Aerogel has many superior properties when compared to other types of insulation, but it comes at a high up-front cost. One participant noted an important caveat: it is important that the maintenance team understands that Aerogel is reusable and should not be thrown away like ordinary insulation; it should be set aside and kept in good condition.
• Proper coatings, stainless steel piping, or products such as thermal spray aluminum (TSA). As one individual stated, “my theory is that we are not going to be successful in keeping the moisture out of the insulation; it’s bound to get in there.”
• Full coverage with radiography coupled with an immediate response plan. One participant described their plant’s strategy in which, over the course of 2 ½ years, all insulated piping was to be inspected using real-time radiography and followed up with profile radiography. In conjunction with the inspections, an immediate response program was implemented to address any major findings within 24 hours. From the outset of the program, significant findings were being discovered (and acted upon) on a weekly basis.

However, it was stated and restated throughout the conversation that the only way to achieve 100% confidence in one’s CUI program is to strip 100% of one’s insulated Class 1 piping. And while this may seem unrealistic or prohibitively costly, one participant detailed the work process of a chemical plant in which CUI was the primary damage mechanism. The process entailed rotating through each section of the facility over the course of 10-15 years, each time stripping 100% of the insulation, inspecting 100% of the piping, repairing where needed, and prepping and recoating the entire section. This process would be repeated into perpetuity. This particular facility witnessed near-zero losses of primary containment (LOPC) for multiple years.

“To achieve 100% confidence, you need to strip 100% of your insulated piping. That’s just the reality of it.”

As part of the CUI inspection process, how much insulation are sites finding that is not needed or unnecessary?

The consensus around the room was that most sites are not keeping track of this information on a systematic basis. One participant suggested that perhaps upwards of 40% of insulation is not necessary and could be removed or replaced with cages, blankets, or thermal insulating paint where personnel protection is necessary.

What are your approaches to managing corrosion under pipe supports or touch point corrosion?

As with CUI, there are no silver bullets when it comes to managing corrosion under pipe supports. The room agreed that, while there are similarities when compared to CUI, it is more complicated due to additional factors such as:

• the numerous different flavors and variations of pipe supports (e.g., pipe on pipe, pipe on concrete, piping trunnions, piping supports) that all come with their own unique set of challenges,
• jurisdictional rules and regulations or internal company mandates that prohibit line lifting, or
• the added complication of insulated piping, which precludes visual inspection from the equation.

Some ideas were offered that should help sites get ahead of the curve, including:

• The first step should be to attain an understanding of what types of pipe supports make up a site. A lot of sites don’t even have their pipe supports identified, much less have an understanding of what kind of supports are being used.
• Be proactive. Operators can be trained to be on the lookout for touch point corrosion, how to differentiate moderate from severe corrosion, and have a clear communication plan when items of concern are discovered.
• And finally, the group mentioned some up-and-coming technologies that are being used or considered in touch point corrosion programs, including pulsed eddy current (PEC), electrical resistance, lamb/surface waves, and long-range/guided wave ultrasonic testing (LRUT/GUL).

“We don’t have a solution right now. We’ve spent an absolute ton of money on it, but we don’t feel like we’re anywhere near ahead of the curve. Right now we’re just trying to figure out how to stop the bleeding.”

Inspectioneering and Pinnacle would like to thank all of the participants for joining in this discussion of these critical issues and sincerely appreciates the dedication of their time to share their thoughts and experiences with our community.