Steam Condenses and a Mega-Vessel Is Destroyed during Commissioning

Steam Condenses and a Mega-Vessel Is Destroyed During Commissioning 

These gigantic pressure vessels were over 100 ft. (30 m) high, 27 ft. (8.2 m) in diameter, and the main body was a straight side cylinder 74 ft. (23 m) long. The cokers were designed for 55 psig (380 kPa) internal pressure. The coker drum has a dome-shaped top 

B unit destroyed as steam condenses and draws from the A unit steam out activities 

The pre-op team steam tested the equipment with up to 50 psig (345 kPa gauge) steam to check for any system leaks. Prior to the steam test, temporary piping 8 inches (20 cm) in diameter was installed to the pre-engineered 24-inch (61 cm) vent to release the steam to the atmosphere. The A Unit and the B Unit coker shared a common vent line to the atmosphere. Unfortunately, the design of the piping modification created a loop that could collect water as the steam condensed. 

The pre-op crew steamed out the B Unit first and vented it through the 8-inch steam vent piping. The failure occurred about four days later. An eyewitness in the operators shelter heard what sounded like a muffled explosion and ran out the back door to see if he could locate fire or smoke. Fortunately, no fire could be seen, but the collapsed coke drum was very visible. 

An expanding U.S. petroleum refinery was increasing its petroleum coke production. It has been said that the new corporate owners of this refinery had to drop their plans for a festive formal publicity announcement of the startup of the unit when a gigantic vessel 

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Steam condenses and a mega-vessel is destroyed during commissioning... 

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