Mill liner installation directly impacts both safety and wear life. Improper installation can lead to premature failure, liner migration, and even catastrophic damage to the mill shell. This guide covers essential best practices.
Pre-Installation Checklist
Before beginning installation:
- [ ] Verify all liners match drawing specifications
- [ ] Check bolt holes align with mill shell holes
- [ ] Inspect rubber backing condition (if applicable)
- [ ] Confirm lifting equipment capacity
- [ ] Review safety procedures with crew
Bolt Torque Specifications
Proper bolt torque prevents liner movement and bolt fatigue:
| Bolt Size | Initial Torque | Re-torque (24-48 hrs) |
|---|---|---|
| M30 | 450 Nm | 500 Nm |
| M36 | 750 Nm | 850 Nm |
| M42 | 1,100 Nm | 1,250 Nm |
| M48 | 1,500 Nm | 1,700 Nm |
Important:Always re-torque bolts after 24-48 hours of operation as liners seat into position.
Common Installation Mistakes
1. Incorrect Bolt Sequence Tighten bolts in a star pattern, not sequentially around the liner. This ensures even seating.
2. Missing Rubber Backing Rubber backing cushions the liner against the shell and compensates for minor irregularities. Never install without it.
3. Forcing Misaligned Liners If a liner doesn't fit, stop and verify dimensions. Forcing installation damages both liner and shell.
4. Inadequate Lifting Points Use properly rated lifting eyes. Never lift by bolt holes alone.
Post-Installation Inspection
After first 24 hours of operation:
- 1Check all bolt torques
- 2Inspect for any liner movement
- 3Listen for unusual sounds indicating loose liners
- 4Document installation date for wear tracking
ATF provides installation support for mill liner customers. Contact us for guidance specific to your mill type.