for Refrigeration Piping Systems
GGS understand the characteristics of refrigeration piping systems, how and where damage can occur, and how it progresses over time. This results in an approach that is specific to your environment and testing that is conscious of the functions of your system. Whether you are performing a routine assessment, evaluating for maintenance or need to learn more about suspect areas, our experience ensures pragmatic results.
Corrosion Under Insulation (CUI) is the most prevalent form of pipe degradation. CUI in the refrigeration industry usually occurs on the top and bottom of horizontal piping. Refrigeration piping usually operates at temperatures below ambient. As a result, water vapor will condense on the external surface of carbon steel piping wherever there is a breach in the vapor barrier of the insulation.
Once water is in contact with the carbon steel, external corrosion will continue to progress until it is resolved. Any water that has entered the insulation will either freeze on the pipe (if it is operating at or below 32F), or it will remain a liquid. This liquid may travel considerable distances from where it was first introduced into the insulation. Water will seek the lowest and/or coldest point in the piping system and remain a constant threat to the integrity of refrigeration piping.
Most refrigerants, including anhydrous ammonia, are not detrimental to the internal surface of carbon steel piping and vessels. For this reason, the presence of external corrosion, not (internal) erosion, is a characteristic of degradation in ammonia refrigeration piping systems.
Testing reveals detailed conditions found at each location. Conclusive wet insulation volumes, severity of corrosion and wall thickness values allow for informed maintenance or replacement planning.