An industrial mechanic was killed when the hydraulic piston
accumulator he was repairing exploded. To fix a leaky seal
inside the accumulator, he drained the hydraulic oil, but not
the nitrogen gas (N2). He did not realize the N2 had produced
extreme pressure on the accumulator’s end-cap and piston,
which blew out in an explosion and struck his abdomen.
Hydraulic accumulators are pressure storage reservoirs that use nitrogen gas to act as a shock absorber for hydraulic systems.
Recommended Preventive Action
Before disassembling any type of accumulator, always release the gas to reduce the internal pressure to atmospheric.
When releasing the gas, have it dissolve in a bucket of water.
Always use N2 when pressurizing accumulators.
Never carry out welding or tapping on accumulators.
All service, repairs and troubleshooting should be done by trained, authorized persons only.
Provide suitable training so maintenance personnel can learn how to use, service and repair equipment safely and effectively.
Discuss proper use of service and repair equipment at safety meetings.
Discuss medical complications associated with oil and air injection injuries.
Always follow the manufacturer’s recommendations.
Write a job safety analysis (JSA) of correct techniques for servicing or repairing gas-charged hydraulic accumulators.
