A Welder’s Leak Test Goes Wrong—Watch Out for Incidental Welding Hazards

Welding has a lot of hazards, but they’re not all directly related to the welding equipment or process. California’s Fatality Assessment and Control Evaluation (CA-FACE) program recently investigated an incident in which a welder was killed while performing a leak test after completing a welding repair.

All welders can learn some valuable lessons from his death.

A leak check goes wrong

At a Southern California waste collection and recycling facility, a 37-year-old welder was repairing a leak in an aluminum hydraulic tank from a waste collection vehicle. The welder had 10 years of experience with his employer and had performed the assigned task before.

At about 7:30 a.m. on March 1, 2013, the welder removed the 55-gallon hydraulic tank from the truck, emptied and disassembled it, welded the leak, and reassembled the tank. To check for leaks, he filled the tank with water and pressurized it with air from the shop air compressor to check for additional leaks.

The air line used to pressurize the tank did not have a regulator or gauge, so no one could be sure, after the fact, 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. The welder was transported to a local hospital, where he was pronounced dead of blunt force trauma to the head.

Lessons for welders

The CA-FACE investigation identified two critical failure points that led to this welder’s death. To prevent similar incidents, employers should:

• Forbid the practice of internally pressurizing tanks to check for leaks. In this incident, the victim performed a hydropneumatic pressure test on a hydraulic tank to check for leaks. Unfortunately, a hydraulic tank used to hold liquid contents is not designed to be pressurized; the practice is unsafe. This welder had used the procedure in the past to check weld integrity without incident, but this time, it led to a fatal accident.
• Instead of using both water and air to pressurize tanks such as this, welders should fill the tank from an elevated water column—a practice that allows the welder to check the tank’s integrity without overpressurizing the tank.
• Train welders in safe work practices for hydraulic tank repair. Repairing pressurized tanks requires specialized training, which should include safe work practices for leak testing. In this incident, although the welder had occasionally repaired hydraulic tanks, he had never been trained in how to do it safely. He probably did not recognize the explosion hazard when he pressurized this type of hydraulic tank.

One more tip on welding hazards

The CA-FACE stopped at two recommendations, perhaps because this tank should not have been pressurized in the first place. However, the investigator did note that the air line used to pressurize the tank had no regulator or pressure gauge.

Even if the tank had been one that could be pressurized, the worker had no way to tell how much pressure he was adding to the tank—and even a tank that can be safely pressurized can be accidentally, and catastrophically, overpressurized. If your welders are welding tanks that should be pressure-tested, ensure they have the equipment to do it safely.

Need more help identifying welding hazards, or other hazards that crop up? You’ll find hazard identification tools galore at Safety.BLR.com®.