Exploding Hydraulic Piston Accumulator
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
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
- Discuss medical complications associated with oil and air injection
- Always follow the manufacturer’s recommendations.
- Write a job safety analysis (JSA) of correct techniques for servicing
or repairing gas-charged hydraulic accumulators.