CUI, just follow the water....

There are still quite some discussions whether water or moisture detection will help us to find CUI. Up until now, it seems that only visual inspections, by dismantling insulation, give a reliable picture. But this method has a tremendous impact om maintenance budget, hence the need for alternative methods.

Is water/moisture detection a reliable method to find CUI? And, what does the presence of water/moisture tell us? It’s pretty basic stuff what water/moisture does in the corrosion mechanism, for carbon steel as well as stainless steel. And that water also increases coating degradation, is top of every corrosion engineers mind. However, the fact that water/moisture has a negative influence on insulation material, is often neglected. Because water/moisture decreases thermal capacity and shortens insulation systems life cycle. It might have different influences on various insulation materials. Nevertheless, in my experience, in the long run, I’ve seen all insulation materials being affected. This brings me to the statement that water/moisture doesn’t belong in insulation systems. A) It can cause CUI, and B) It definitely will shorten the residual life cycle of the insulation system.

There are various methods in water detection. NDE techniques, like neuron backscatter and in some cases thermographic. And there are different water detection systems available, from simple water indicators to sophisticated sensors. Recently I’ve seen some test done based on capacitive sensing technique and tests with coated optical fibers. Both tests were still in a development stage, but it proofs my earlier point, that asset-owners are willing to invest in finding detections methods that can limits the need for expensive visual inspections.

It’s my opinion that at current stage we don’t have a reliable method or technique for CUI detections. But, that these techniques show us with 100% certainty the insulation systems condition.

And in line NACE systems approach, we should not only focus on “C” part of CUI but also the “I”, and as such mitigate CUI.