Microcracking of Fusion Bonded Epoxy a Rare Phenomenon

Abstract Designing robust corrosion protection system for the internals of pipeline in aggressive services is paramount for system integrity and business continuity. Fusion Bonded Epoxy (FBE) coatings are primarily utilized for corrosion protection on internals of pipelines. Pipes comes with shop applied quality assured internal FBE coating. On completion of onsite welding these joints are field coated to protect the internal cutback areas. This paper discusses a rare phenomenon of microcracking discovered on the FBE coated internal field joints. A thorough investigation was undertaken to discover the root causes of such defects. These joints were cut and analyzed in the lab, the field application conditions were simulated in the shop and joints coated to study the different contributing variables to such defects. Coated plates were subjected in the lab to various conditions simulating the field ones, to create such microcracking for better understanding and insight on this occurred phenomenon. This paper provides conclusive results on identified factors contributing to occurrence of such microcracking and provides further recommendations for preventions of its recurrence.