Multi-piece rims: know the dangers

A multi-piece wheel is a vehicle wheel consisting of two or more parts, one of which is a side or locking ring that holds the tyre and other components on the rim wheel by interlocking the components when the tyre is inflated.

5-Piece Rim

There are certain hazards of working with large vehicle tyres. The principal difference between accidents involving single-piece rim wheels and those involving multi-piece rim wheels is the effect of the sudden release of the pressurised air contained in the rim wheel.

Single-piece rim wheel accidents occur when the pressurised air contained in the tyre is suddenly released, either by the bead breaking or by the bead slipping over the rim flange. In a multi-piece rim wheel accident, the wheel components separate and are released from the rim wheel with violent force. The severity of the hazard is related not only to the air pressure but also to the air volume.

The amended safety standard for servicing single-piece and multi-piece rim wheels has four major requirements:

  • Training for all tyre-servicing employees
  • The use of industry-accepted procedures that minimise the potential for employee injury
  • The use of proper equipment such as clip-on chucks, restraining devices or barriers to retain the wheel components in the event of an incident during the inflation of tyres, and
  • The use of compatible components

There has been more than a 70% reduction in multi-piece rim wheel servicing injuries since the original standard was issued in 1980 – based on a review of the record of multi-piece rim wheel accidents investigated by OSHA. Similar results have been experienced with the regulation of single-piece rim wheel servicing where workers also face a significant risk of serious injury or death.

Some of the safety procedures to take when working with single and multi-piece rim wheels will include:

  • Standing to one side and keeping your face above the fender when checking or inflating the tyres
  • Remove the valve core to deflate the tyre completely before removing the tyre from the rim
  • Mount and remove tyres from the narrow ledge side of the wheel and avoid damaging the tyre beads
  • Mount only rims and tyres of compatible diameter and width
  • Inspect the rim flanges, bead seating surfaces and tyre for defects and foreign particles. Replace any rim that is rusted, cracked, broken, bent, corroded or damaged
  • Do not exceed the vehicle or manufacturer’s recommended inflation pressure and use valves that are appropriate for the use of the tyre

Check out our full line of  fully-certified tyre cages for OTR tyres.

Chemvulc tyre safety cages OSHA no. 29 CFR part 1910.177 COMPLIANT!

Sources: Ultimatetintandwheel, osha, 6speedonline and ESCO

Repairing of ultra-large mining tyres