Welding Lugs onto Liners

By on August 13, 2008

This alert warns quarry operators, maintenance workers and other users of crushers of the danger of substandard welded lifting lugs fitted to austenitic manganese steel (AMS) internal crusher liners.

RECENTLY a liner was dropped, while being installed in a jaw crusher at a quarry, due to lifting lug failure. A worker had his knee shattered, after being hit by a length of pipe struck by the falling liner.

This incident could have easily resulted in more serious injuries or even death.

Many liners do not have cast-in lifting lugs and a common industry practice is to weld temporary lifting lugs onto the liners to assist with their removal or fitting.

In this instance a temporary lifting lug had been welded onto the liner and while being lifted into position, the welds failed.

While AMS liners are weldable, they are susceptible to carbide precipitation and embrittlement, unless specific precautions are taken.

Sub-standard welding on lifting lug

RECOMMENDATIONS

WorkSafe recommends the following precautions are taken when removing or fitting these liners:

When welding lifting lugs to AMS liners:

  • Welders are suitably qualified and competent in welding this type of steel
  • A welding procedure should be developed to ensure the lifting attachments are suitable for the size of the liner, including:
    • having the appropriate safe working load (SWL) rating
    • dimensions and type of steel to be used for the lug
    • liner surface and weld preparation
    • location of lug on the liner to maximise lifting stability and minimise stress on welds, consideration should be given to installing multiple lugs for extra safety
    • length and locations of weld fillets
    • the welding rods to be used
    • inspection and test procedure to verify the lifting lug’s strength, prior to use

When lifting the crusher liner:

  • People not involved in the process are kept well clear of the area
  • Never stand or have any part of the body underneath the suspended load
  • The work area should be kept clean and free of loose components
  • All lifting components should be of the appropriate rating and be in serviceable condition
Liner fitted to jaw crusher

FURTHER INFORMATION

When developing welding procedures advice can be obtained from:

  • The manufacturer or supplier of the liner
  • AS/NZS 1554 – Structural steel welding for welding load bearing components
  • Welding rod manufacturers on the selection of the appropriate welding rod
  • An experienced mechanical engineer

Information on maintaining plant can be found in WorkSafe’s Guidance Note – maintaining plant in safe working order.

Information on lifting accessories can be found in WorkSafe’s Handbook – working safely with bridge and gantry cranes. Copies of this and other publications can be accessed and downloaded from WorkSafe’s website at www.worksafe.vic.gov.au

Further general advice to improve health and safety at your workplace can be obtained by contacting WorkSafe’s Advisory Service toll-free on 1800 136 089.

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