A major failure mode of FBE coating and/or epoxy lining during service is the formation of blisters during hot water immersion and/or when subjected to cold wall effect. There are several reasons for a coating to develop blisters. Osmotic blistering is a common explanation for the formation of blisters in hot water immersion. However it has been observed that even without salt contamination FBE/epoxy coating can still blister under hot water soak and cold wall effect. The purpose of this paper is to evaluate the blistering mechanisms in the coating and to relate the formation of blisters to the swelling of the FBE/epoxy coating due to water absorption and cold water effect. The results of the study can be used to guide the coating manufacturers to develop more appropriate coating products to resolve the blistering issues and to assist the end users to select proper coating materials for their specific applications. Key Words: FBE/epoxy coating blistering hot water immersion cold wall effect swelling