Page 42 - 4ConveyorBeltCatalog2010

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Conveyor Design Information
Conveyor Belt Trouble-Shooting Guide
Problem Probable Causes
- from most likely to least
Problem Probable Causes
- from most likely to least
Belt runs off at tail pulley 7 14 15 17 20 - - - Excessive bottom cover wear 20 15 5 19 21 22 9 -
Belt runs off at all points of the line 25 17 14 20 3 16 - - Excessive edge wear, broken edges 25 3 17 9 1 20 2 -
One belt section runs off at all points
of the line
2 11 1 - - - - - Excessive top over wear, gouges,
rips, ruptures, and tears
12 24 17 15 9 5 - -
Belt runs off the head pulley 14 22 20 16 - - - - Cover swells in spots or steaks 9 - - - - - - -
Belt runs to one side throughout the
entire length at specifc idlers
14 16 20 - - - - - Longitudinal grooving or cracking of
top cover
26 15 20 12 - - - -
Belts slips 19 7 20 15 22 - - - Cover checked or brittled 9 - - - - - - -
Excessive belt stretch 19 7 22 10 - - - - Belt hardens or cracks 9 23 22 - - - - -
Belt breaks at or behind fasteners, or
fasteners tear loose
13 10 22 6 8 9 - - Longitudinal grooving or cracking of
bottom cover
15 20 22 - - - - -
Belt breaks at or behind fasteners, or
fasteners tear loose
2 23 13 22 21 10 6 8 Fabric, decay, carcass cracks,
gouges, ruptures, soft spots
12 21 5 10 9 - - -
Vulcanized splice separation 23 10 20 14 19 2 - - Ply separation 13 23 11 9 4 - - -
1. BELT BOWED: Avoid telescoping belt rolls or storing them in damp locations. A new belt should straighten out when "broken
in" or complete system must be reinspected.
2. BELT IMPROPERLY SPLICED OR WRONG FASTENERS: Use fasteners recommended by the manufacturer. Retighten after
running for a short while. If improperly spliced, remove old splice and resplice. Set up regular inspection schedule.
3. BELT STRAINED (or elongated on one side): Allow enough time for new belt to "break in." If belt does not break in properly or is
not new, remove strained section and splice in new piece.
4. BELT SPEED TOO FAST: Reduce speed.
5. BREAKER STRIP MISSING OR INADEQUATE: When service is lost, install belt with proper breaker strip.
6. COUNTERWEIGHT TOO HEAVY: Recalculate weight and adjust counterweight accordingly. Reduce take-up tension to point
of slippage; retighten slightly.
7. COUNTERWEIGHT TOO LIGHT: Recalculate weight and adjust counterweight or screw take-up accordingly.
8. DIFFERENTIAL SPEED WRONG ON DUAL PULLEYS: Make necessary adjustment and observe operation closely.
9. DAMAGED BY ACIDS, CHEMICALS, OILS, OR DETERIORATION BY ABRASIVES, HEAT OR MILDEW: Use belt
designed for specifc condition. For abrasive materials working into cuts and piles, repair with cold pack or with permanent repair
patch. Seal metal fasteners or replace with vulcanized step splice. Enclose belt line for protection against rain, snow or sun. Do not
over lubricate idlers.
10. DRIVE UNDERBELTED: Recalculate maximum belt tensions and select correct belt. If line is over-extended, consider using two
fight system with transfer point. If carcass is not rigid enough for load, install belt with proper fexibility when service is lost.
11. EDGE WORN OR BROKEN (Permitting moisture penetration and belt shrinkage on one side): Repair belt edge. Remove
badly worn or out-of-square section and splice in new piece of belt.
12. EXCESSIVE IMPACT OF MATERIAL ON BELT OR FASTENERS: Use correctly designed chutes and baffes. Make vulcanized
splices. Install impact idlers. Where possible, load fnes frst. Where material is trapped under skirts, adjust skirtboards to minimum
clearance or install cushioning idlers to hold belt against skirts.
13. EXCESSIVE TENSION: Recalculate and adjust tension. Use vulcanized splice with recommended limits.
14. IDLERS OR PULLEY SHAFT OUT OF SQUARE WITH CENTER LINE OF CONVEYOR: Realign and install limit switches for
greater safety. Check conveyor manufacturer's manual or guide.
15. IDLERS FROZEN: Free the idlers; then lubricate, but do not overdo it.
16. IMPROPERLY PLACED IDLERS: Relocate idlers or insert additional idlers spaced to support belt.
17. IMPROPER LOADING: Feed should be in direction of belt travel and at belt speed, centered on the belt. Control fow with
feeders, chutes and skirtboards.
18. IMPROPER STORAGE OR HANDLING: Contact your representative for storage and handling tips.
19. INSUFFICIENT TRACTION BETWEEN BELT AND PULLEY: Increase wrap with snub pulleys. Lag drive pulley. In wet
conditions use grooved lagging. Install correct cleaning devices on belt and centrifugal switch for safety.
20. MATERIAL BUILD-UP (on pulleys and idlers): Remove accumulation and install cleaning devices, scrapers, and inverted "V"
decking.
21. MATERIAL FALLING BETWEEN BELT AND PULLEY: Use skirtboards properly. Remove accumulation.
22. PULLEY LAGGING WORN: Replace worn pulley lagging. Use grooved lagging for wet conditions. Repair loose protruding
bolts.
23. PULLEYS TOO SMALL: Go to a larger diameter.
24. RELATIVE LOADING VELOCITY TOO HIGH OR TOO LOW: Adjust chutes or belt speed. Consider use of impact idlers.
Observe operation closely.
25. SIDE LOADING: Load in direction of belt travel.
26. SKIRTS INCORRECTLY PLACED: Install skirtboards so that they do not rub against belt.