A welder died when
struck by a piece of a hydraulic tank that came apart after being pressurized
with air and water to check for leaks.
The employer of the
victim was a waste collection and recycling company that had been in business
for over 50 years and had approximately 1,300 employees. The facility where the incident occurred was
the company’s main transfer station and maintenance yard for their vehicles and
equipment. There were 45 employees at
this facility at the time of the incident.
The victim was a
38-year-old Hispanic male welder who had been working for the company for 10
years. The victim’s primary job task was to repair and fabricate trash bins. He
was born in Mexico, had been in the United States for 18 years, and had a 12th
grade education.
On the day before
the incident, the victim was assigned the task of repairing a leak in an
aluminum hydraulic tank from a waste collection vehicle. He had performed this
task in the past on several occasions.
The victim removed
the 55-gallon hydraulic tank from the truck, then emptied and disassembled it,
welded the leak, and reassembled the tank. On the day of the incident, the
victim filled the tank with water and pressurized it with air from the shop air
compressor to check for additional leaks.
The airline used to
pressurize the tank did not have a regulator or gauge, and it is not known how
much air pressure was used. As the victim was leaning over the tank checking
for leaks with a flashlight, the rear end plate of the tank blew off under
pressure and struck the victim in the head.
Other welders in the
shop ran to the victim’s aid and called 911. Emergency responders transported
the victim to the local hospital where he was pronounced dead from his
injuries. The cause of death according
to the death certificate was blunt force injuries to the head.
In order to prevent
future incidents, welding companies should ensure that:
1.
Hydraulic
tanks are not internally pressurized to check for leaks. Rather than the use of both water and air to
pressurize tanks such as this, an alternative method would have been to fill
the tank from an elevated water column. Using this method, excess pressure
could not occur inside the tank. Had the victim used this alternate method, the
tank could not have been pressurized, causing an explosion.
2.
Welders
receive training on approved procedures for repair of hydraulic tanks. When repairing hydraulic tanks, welders
should undergo specialized training that includes proper procedures for leak
testing. In this incident, the victim occasionally repaired hydraulic tanks but
did not have specific experience or training in tank welding. He likely did not
recognize the explosion hazard when he pressurized this type of hydraulic tank.
Had the victim been specially trained in hydraulic tank repair, he probably
would not have used hydro-pneumatic pressure testing to check for leaks.
References:
Division of
Occupational Safety and Health - Title 8 regulations, Subchapter 1. Unfired
Pressure Vessel Safety Orders Article 10. Safe Practices - §560. Safe
Practices.
Subchapter 7
- General Industry Safety Orders, Group 2. Safe Practices and Personal Protection,
Article 7. Miscellaneous Safe Practices - §3301. Use of Compressed Air or
Gases.