I have always wanted to get a working example of what goes on behind piping insulation once the vapor barrier has been compromised. This video is one from a recent inspection and just happens to be in an NH3 refrigeration process, but this issue is found in any process where the temp of the pipe can condense moisture out of the air. Once the air makes it through the vapor barrier and insulation and contacts the cold pipe, it condenses the “humidity” (i.e. moisture) out of the air. The insulation then absorbs the liquid and holds it against the pipe 24/7. Even properly treated/coated pipe can’t stand up to this hot/cold/hot/cold cycling and we begin to corrode the pipe from the “outside-in”. Often times just a visual walk down of the piping will fail to identify any issues as the corrosion is hidden under the insulation. This is why it is so CRITICAL that those who do the API 570 Visual Inspection be properly trained in how to identify failures in the vapor barrier. Here the video, with me pushing on the insulation like a sponge…