Plant structure — cracks, corrosion, loose bolts and leaning silos
Symptom
Rust streaks from a weld or joint, cracks in the paint at welds, heavy corrosion at base plates, loose or missing bolts, a platform vibrating more than before, or a plant or silo leaning.
Likely causes
- Corrosion where water and cement collect - base plates, legs at ground level.
- Fatigue cracks from vibration at mixer supports, vibrator mounts and conveyor heads.
- Bolts loosened by vibration.
- Overload or over-pressure on silo legs; impacts from trucks and loaders.
- Foundation settlement or anchor failure; unauthorised changes.
Most likely and cheapest to check first.
Checks
- Clean first - cement, dust and grease hide cracks.
- A hairline crack in the paint usually means the steel is cracked below - mark, photograph, dye-penetrant test.
- Tap rusty areas with a hammer (safety glasses) to see the sound steel.
- Check anchor nuts, grout under base plates, plumb and level; compare with the last inspection photos.
Fix
- Replace bolts with the same size, grade and coating; tighten groups in sequence; re-check bolts on vibrating supports.
- Grind out cracks fully, re-weld by a qualified welder, and fix the vibration cause.
- Clean rust to sound steel, prime and paint, or zinc-rich paint on galvanising; add drain holes.
- Load-bearing repairs and any modification approved by an engineer.
Stop the equipment if
A column is bent, a silo leg or bracing is cracked, anchor nuts are missing, or the plant is visibly leaning. Empty the silo or bin and call an engineer.
Parts you may need
Inspection rhythm
| Interval | Who | What |
|---|---|---|
| Daily | Operator | Obvious damage, missing handrails or gratings, impact marks |
| Monthly | Technician | Platforms, handrails, gratings, visible bolts, rust spots, vibrating supports |
| Yearly | Competent person or engineer | Full inspection with records and photos; anchors; plumb and level |
| After an event | Engineer | After over-pressure, impact, earthquake, storm, fire, or before relocating |
DANGERWhen welding on the plant, put the earth clamp close to the weld so current never passes through load cells, bearings, gearboxes or sensors. Welding is hot work - permit, fire watch, extinguisher.
⚠ Every check inside a machine starts with full lockout. Safety disclaimer