Belt conveyors
Belt conveyor troubleshooting: symptom, likely cause and action
Quick answer
A quick lookup from the visible symptom to the usual causes and the first thing to do.
How to use this table
Work from the symptom to the cause that matches what you see where it happens: only at one spot, at one part of the belt, or everywhere. Many causes repeat (dirt on rolls, stuck rolls, worn lagging, off-centre loading, tension), so fix those first.
Symptom, cause and action
| Symptom | Likely causes | First actions |
|---|---|---|
| Belt runs to one side at one spot | Material build-up on rolls; stuck rolls; idlers or pulleys out of square; crooked frame; idler stands off centre; structure not level | Clean and free the rolls; reset the idlers in that area; straighten or level the frame |
| One section of belt runs off wherever it goes | Splice not square or wrong fasteners; belt bowed; edge worn or broken | Re-splice squarely; check storage and handling; repair the edge |
| Belt runs off for a long distance or the whole length | Off-centre or poor loading; belt off centre at the tail; dirt on rolls | Centre the chute and discharge in the belt direction; add return training idlers before the tail |
| Belt runs off at the tail pulley | Belt not centred through loading; spillage; pulleys or idlers out of square | Add training idlers on the return run; clean up spillage; realign |
| Belt runs off at the head pulley | Worn lagging; build-up; out-of-square pulleys or idlers | Replace lagging; install cleaners; realign |
| Belt slips, or slips on starting | Too little traction or wrap; worn lagging; counterweight too light; stuck rolls; underbelted drive | Lag the drive pulley (grooved if wet); add wrap with a snub pulley; recalculate the take-up weight or tension |
| Excessive belt stretch | Installed with too little tension; take-up in the wrong start position; too little take-up travel; tension too high; counterweight too heavy; drive underbelted | Pull the belt through under the right tension; reposition the take-up; recalculate tension and belt rating |
| Gouged or stripped top cover | Skirtboards too tight or wrong rubber; impact at loading; material hanging in the chute | Open the gap in the travel direction; add cushion idlers; widen or improve the chute |
| Uniform top-cover wear | Dirty or stuck return rolls; cover too thin; spillage; off-centre loading; too much sag between idlers | Clean and free rolls; use a heavier cover; reduce idler spacing or raise tension if too low |
| Severe pulley-cover wear | Stuck idlers; slip on the drive; material trapped under the belt; bolt heads above the lagging; too much forward idler tilt | Free the rolls; fix slip; add a plow before the tail pulley; use vulcanized lagging; limit tilt to 2 degrees |
| Cracked or grooved bottom cover | Stuck idlers; slip on the drive pulley; spillage; worn lagging | Free rolls; lag the drive; replace lagging |
| Covers harden or crack | Heat or chemical damage; poor storage | Use a belt made for the condition; correct storage |
| Cover swells in spots or streaks | Spilled oil or grease; over-greased idlers | Housekeeping; reduce grease; check seals |
| Belt breaks at or behind fasteners | Fastener too long for the pulley; wrong fastener or tightness; tension too high; heat or chemical damage | Smaller fasteners or larger pulleys; correct fastening and a check schedule; reduce tension |
| Vulcanized splice separates | Poor splice; pulleys too small; tension too high; trapped material; poor transition | Re-splice to procedure; use larger pulleys; check transition distance; add plows |
| Edge wear or broken edges | Off-centre loading; spillage; belt hitting the structure; bowed belt | Centre the load; add training idlers; check roll storage |
| Transverse breaks at the belt edge | Edges fold up on the structure; poor transition at the pulley; severe convex curve | Add limit switches and clearance; correct transition; shorten idler spacing or increase curve radius |
| Ply separation | Belt too stiff across its width; pulleys too small; heat or chemical damage; tension too high | Use the right belt; larger pulleys; belt designed for the condition |
| Carcass fatigue at the idler junction | Poor transition at the pulley; excess idler tilt; gaps between roll ends; belt too light across its width | Correct transition; limit tilt to 2 degrees; replace idlers; heavier belt |
Takeaway. The same few causes explain most belt problems: loading, tension, dirt and alignment. Check them in that order.
Put it to work in the tool