A fire that broke out at Sunoco's Marcus Hook refinery in May, destroying part of Sunoco's Marcus Hook refinery, could have been caused by a rusted 10-inch pipe. The corrosion is reported to have occurred over many years and affected an area of less than one square foot. It was caused by moisture trapped between the pipe and a loose steel sleeve. The corroded pipe was located on top of a concrete support about 18 feet above the ground, obscured from view. The pipe maintained a constant temperature of about 60 degrees, which made the line sweat in humid weather, causing moisture to build up. No injuries/calamities were reported in the inferno that almost destroyed the unit. It is believed that this pipe ruptured and caused a calamitous natural-gas leak. Investigators concluded that a feed line to the refinery's ethylene unit failed and released gas that caught fire.
Company spokesperson said that efforts have been stepped up to examine piping systems at all its facilities to address immediate problems and had begun a process to revise its standard inspection practices to make them more rigorous. The company is in the process of implementing a special-emphasis program for high-risk systems to be sure similar structures with similar conditions do not exist at any Sunoco facilities. Sunoco will have a third party review its inspection practices to identify other areas for improvement. The company has decided to not to reopen the ethylene unit because of depressed demand.