Counterbalance valves may seem an obvious choice in preventing an accident of this type, but they cannot be relied upon. An engineer was recently injured when a machine he was working on dropped i’s load as he attended to a leaking rod seal. Although he took all the necessary precautions of lowering the load to remove pressure, he was startled and hurt when a high pressured jet of fluid fired at him from the fitting. The counterbalance valve had trapped pressure and caused this situation.
What to consider when avoiding this dangerous situation:
- The system should be designed with a focus on safe and checkable de-energisation. All ‘pockets’ of energy should be able to be removed. Check that pressure cannot re-accumulate or that it has been isolated until all maintenance or servicing has been completed.
- Implement a system such as Safe-T-Bleed to lower pressure.
- Make it mandatory for all hydraulic system focused workforce to have de-energisation and lockout training. There must be clear understanding of the storage of energy in hydraulic systems.
- Write and distribute a procedure on how to lock out and de-energise the equipment.
- Hold regular drills for lock out and de-energisation to verify that staff know how to get a machine to the point where it is safe to work on it. Discussing the approach in an educational classroom setting is one thing, but being able to implement it when under pressure in the workplace is another. There can be absolutely no room for mistakes in this fatally dangerous practice!
- Make it a punishable offence to ‘crack’ connectors in the removal of stored energy.
- If it’s not possible to verify that a machine is de-energised and safe due to its design, then contact the manufacturer. Don’t follow any instructions to crack a connector – it’s fatally dangerous!
- Don’t purchase machinery without understanding its de-energisation and verification situation.
It’s essential that all hydraulic equipment is designed with safety in mind, in particular with de-energisation. High pressure oil jets can leave to serious injury or death as they can penetrate your skin. Safety should not be taken lightly.