Failure of co-disposal basalt-lined Y PieceMines safety alert no. 193 | 04 April 2008 | Version 1
All mine types
During clearing of a blocked co-disposal pipe line at a mine preparation plant, a basalt-lined steel Y piece pipe has failed under pressure at the position of the shop weld where two lengths of pipe are welded together to form the Y branch.
A spiral-wound pipe shell had been cut and welded to form the Y piece. The weld is referred as the shop weld.
The Y piece failed under pressure, discharging fluid and pieces of basalt approximately 25m.
The weld area of the Y piece has been identified as sub-standard with the shop weld not penetrating between the two faces of the pipe.
Comments and recommendations
- The pipe line was subjected to a pressure of approximately 1100kPa at the pump discharge.
- All mine sites conduct an audit and inspection on all basalt-lined Y pieces to determine if the piece has sustained damage or wear and to replace any suspect pipe.
- All mine sites contact the pipe supplier/manufacturer to ensure that a quality assurance system is in place to prevent this type of incident happening in the future.
Authorised by Gavin Taylor - Chief Inspector of Coal Mines
Issued by the Queensland Department of Mines and Energy