Fire to Ammonia Refrigeration System
W&A was retained to verify damage to a cold-storage ammonia refrigeration system due to fire. Although equipment damage was obvious in the immediate area of the fire, there was concern over whether the system sustained internal damage. While performing remediation, the vendor observed that the ammonia refrigerant, which should be colorless, had a blue-green color. The vendor believed the discoloration was produced by a reaction from the ammonia and the refrigeration construction materials when the refrigerant temperature increased due to the fire. They recommended replacing the entire refrigerant system, including items such as piping, valves, compressors, expansion tanks, evaporator coils, and other hardware components in direct contact with the refrigerant. Their rationale for replacement was that the system had been exposed to ammonia refrigerant at high temperatures, which can accelerate stress-corrosion cracking in ferrous metal alloys.
To determine the impurities that produced the discoloration, we prepared a test protocol and arranged for an independent lab to chemically analyze refrigerant samples. The results of the metal scans for individual metallic elements were compared with the construction materials used in the refrigeration system. This process allowed us to isolate the component parts of the system that were potentially affected and remediate only those parts, resulting in a cost savings for our client of approximately $1.1 million.