An explosion and fire occurred at the Humber Refinery on April 16th 2001, following the failure of
a 6-inch overhead pipe from a De-ethanizer column in the Saturate Gas Plant. Investigation revealed
that the failure of the pipe was due to internal corrosion associated with a water wash injection location
that had not been identified by the refinery pipework inspection regime.
This paper describes the chain of events that led to the failure, as well as determining the
corrosion mechanism of the failure, which was not known at the time. The corrosion mechanism was
determined to be acidic sour water corrosion due to the significant presence of hydrogen sulfide. The
paper also describes the mitigation procedures put in place and details the current status of the system.