What priority classification should be used for CUI (corrosion under insulation) thermography inspections?
CUI is more difficult to classify than electrical thermography. There are many criteria that affect the likelihood of corrosion, including condition of insulation, operating temperature, and surface protection. To classify the risk based on temperature is normally done as follows*;
High between 30 and 120 C
Medium between -4 and 30, or 120-260 C
Low above 260 C
You have to remember that you will find the areas with poor insulation quality, and this is in itself a risk factor. I don’t personally recommend classifying the risk with CUI, I would use thermography to find the suspected areas and then follow then up with a check, and then repair the insulation.
* source Nowicki