Ammonia Refrigeration Piping – Corrosion Under Pipe Label (CUPL)

If you are not aware, corrosion under pipe labels is becoming more and more apparent.  This last week we were in the processing of replacing an old label and found the beginning of some surface rust and corrosion pitting.  Thank goodness we caught it at this time.  We do not recommended applying an label directly to the painted steel pipe with the adhesive sticker, especially if that pipe can transition through the dew point temperature of the environment is is located.  When is the last time you looked under your pipe labels?  Do you have a PM to make sure that CUPL is not occurring in your facility?