Analysis of a corrosion under insulation failure in a carbon steel refinery hydrocarbon line

(in lingua inglese)

The material of construction of the pipe was consistent with codes and standards and fit for purpose. The pipe coating system appeared to be compliant with specifications; there was no evidence to suggest that an inadequacy of the coating contributed to failure. The lagging system appeared to be fit for purpose, there was no evidence that inadequacy of the intended system contributed to failure. Failure of the pipe had occurred as a result of corrosion under insulation (CUI), the rate of corrosion was entirely consistent with published data. The wall thickness of the pipe had been reduced to a level that would not support the internal pressure; the remaining ligament had then failed as a result of a ductile overload.