Propane Tank Fire & Bobtail BLEVE*
A bulk propane facility with one 18,000-gallon tank and a few bobtails serviced a small rural community. It was located in close proximity to a number of low-income residences and was built along a main town road. The 18,000-gallon tank was 70 feet from the road and there was a convenience-store-gas-station plus a pizza parlor across the street. There was a slight downhill slope from the gas station and pizza parlor toward the propane facility.
One evening a small, unattended pickup truck used for pizza delivery rolled down the slope, crashed through the chain link fence gate and impacted the 18,000-gallon tank's piping. Because there was no breakaway joint in the piping and the excess flow valve was only screwed in a few threads, the impact pulled the excess flow valve completely out of the tank.
At that point liquid propane began to pour out of the tank and roll further downhill via a ravine toward the low-income housing. Eventually, the propane fog found an ignition source resulting in a very large deflagration and fire. During the course of the resulting fire a bobtail parked about 14 feet from the 18,000-gallon tank exploded (BLEVED). Amazingly, no one was seriously injured.
In the aerial photo above, the white 18,000 gallon tank is just northeast of center and the pizza parlor across the street is to the northeast of the tank.
The investigation revealed that there had been at least four previous incidents of vehicular impact at this facility in the several years before this incident. One incident involved a Corvette that smashed through the fence and wedged underneath the 18,000-gallon tank. In another incident a motor home hit a 1,000-gallon tank. A major issue in the investigation was whether or not the facility met its NFPA 58 obligation with respect to vehicular protection.
Dr. Fox of Chemaxx
has investigated several other propane fires including a fire while a catering
truck was being filled at a bulk plant, two house fires and a BBQ grill fire.
He has also been a safety consultant to a propane company. Chemaxx also has an
Associate with over 25 years of hands-on experience in the propane industry.
*Boiling Liquid Expanding Vapor Explosion
Dr. Fox is an explosion expert, fire expert, and chemical expert with extensive experience in OSHA chemical regulations and chemical safety.
©2005 CHEMAXX, INC