Food & Beverage Processing

Another major concern for Faribault Foods and its contractors was corrosion under insulation (CUI). This phenomenon occurs when halogen compounds (compounds of chlorine, bromine, or fluorine) become trapped with moisture under the insulation, corroding even stainless steel piping. There are extensive process piping systems and pieces of equipment in this facility made from stainless steel. In an environment such as a food-processing plant, there is the constant threat of moisture and water vapor entering the insulation system. This is especially true if there is a meat processing or cooking element involved, such as with chili or seasoning meat for beans, which have long process times (compared with vegetables, fruits, and juices) and generate high temperatures and high humidity. High heat with humidity and steam can drive moisture into an insulation system, so the system needs to be very moisture resistant, well-sealed, and easy to clean. Chlorine is one of the most common chemicals used for cleaning wash downs, so the system also needs to be impermeable. This is managed with: (1) Effective sealing of insulation systems, especially at all termination points; and (2) An insulation that contains low-halogen compounds that could react with moisture. In such circumstances, the insulation that will be in contact with stainless steel piping should be tested for meeting the requirements of ASTM C795 and/or C692 to avoid the content of halogen compounds that can leach out when water is introduced, combining with the moisture, and creating a solution that can corrode stainless steel piping.