Anhydrous ammonia nurse tank explosion

The photos below are from a 1,000-gallon anhydrous ammonia nurse tank explosion June 6, 2005, at the Cenex Co-op yard in Morris, Minn. The explosion released approximately 841 gallons of anhydrous ammonia to the atmosphere.

Prior to the incident, an employee filled the subject nurse tank to 85 percent capacity with anhydrous ammonia at approximately 3:30 p.m. After the tank was filled, it remained at the filling-station dock and the employee vacated the yard.

The explosion was reported to emergency response teams at approximately 6 p.m. They discovered a ruptured 1,000-gallon anhydrous ammonia nurse tank that was in two pieces. A portion of the rear head was lying near the filling dock and the remainder of the tank was approximately 100 yards away. Upon explosion, the vessel ricocheted off the earth, skipped across the yard and slammed into a parked utility tractor and an automobile before coming to rest. Other pressurized anhydrous ammonia tanks were in the yard. The ruptured vessel missed these tanks by 25 yards.

No employees or customers were on site. No fatalities occurred. A local farmer who lives three-tenths of a mile to the west was taken to the hospital for ammonia inhalation treatment.

Forward end of vessel showing impact damage	Severed tractor and damaged automobile	The ruptured vessel missed these tanks by 25 yards
Portion of vessel rear head	Weld deposit and arrow pointing to small crack in vessel head	Lifting lug on fragmented vessel head
Vessel level indicator float assembly	Vessel filling and gauge components	Vessel bleeder valve and indicator gauge
Point of vessel where fracture meets circumferential weld	Vessel safety valve	Vessel internals looking in from opened end