A RECENT fatality in NSW where a container handling reach stacker’s five piece split rim wheel assembly exploded has again brought attention to the danger of wheel removals and replacements on forklifts with pneumatic tyres for the local materials handling industry.
Incidents of this kind, while not a first, is not a rarity. MLA Holdings says technicians and tyre fitters need to be especially wary around big trucks with multi piece rims and pneumatic tyres, and follow safety regulations in regards to these pieces of equipment.
A relatively minor crack or fault on the tyre or rim can quickly develop into an explosion due to the high air pressure within, which can reach up to 1100 KPA or 155 PSI.
Removing, replacing wheels
When removing a wheel from a heavy truck or container handler, the tyre must be fully deflated, neutralising all the inside air pressure. This will reduce the risk of a catastrophic wheel explosion during the process.
MLA Holdings says it uses a wheel and tyre safety supplement to instruct tyre fitters and technicians on how to safely and correctly remove and replace tyres.
When removing wheels, the truck should be parked on level ground in a safe working area. The technician should chock the wheels and isolate the ignition and batteries.
Jack up the truck at the jack points and secure with an axle support device. It is important to not rely on just the jack.
Before removing any wheel nuts fully deflate all wheels that are to be removed.
Remove the wheel nuts and use a suitable lifting device to remove the wheel.
When replacing the wheel, inspect the tyre and rim for damage and cracking, and reject if faulty.
The wheel should be placed into the tyre safety cage and inflated to the recommended inflation pressure.
The inflated wheel should be inspected for defects, then fully deflated for removal from the tyre safety cage. If defects were found, the technician should rectify them.
Using a suitable lifting device, place the wheel onto the truck and tighten wheel nuts in correct sequence to recommended torque setting.
Even at this stage, precautions need to be taken in case of a tyre explosion.
A protection device placed near the wheel assembly will minimise the potential trajectory of explosions.
Inflate the tyre to the recommended inflation pressure from outside the trajectory zone, once again inspect the wheel, before remove the protection device, axle support device and jack.
Test run truck and retighten wheel nuts in correct sequence to recommended torque setting.
Return the truck to service, but after 10 hours of use, the wheel nuts should be retightened in the correct sequence to the recommended torque setting.