We manufacture in Italy
WE SUPPLY WORLDWIDE

Customer service

Trouble Shooting

1.Conveyor runs to one side at given point on structure
Idlers or pulleys out-of-square with belt centre line

Adjust idlers in affected area

Conveyor frame or structure crooked

Modify the affected area

Idler stands not centered on belt

Re- adjust idlers in affected area

Sticking idlers

Free idlers and improve maintenance and lubrification

Buildup of material on idlers

Remove accumulation
Improve maintenance
Install screapers and other cleaning devices

Structure not level

Level structure in affected area

2.Particular section of belt runs to one side at all points on conveyor
Belt not joined squarely

Remove affected splice and resplice

Bowed belt

For new rubber conveyor belts this condition should disappear during  brake-in
In rare cases belt must be straightened or even replaced
Check storage and handling of belt rolls

3.Belt runs to one side for long distance or entire length of belt
Idlers or pulleys out-of-square with belt centre line

Adjust idlers in affected area

Conveyor frame or structure crooked

Modify the affected area

Idler stands not centered on belt

Re- adjust idlers in affected area

Buildup of material on idlers

Remove accumulation
Improve maintenance
Install screapers and other cleaning devices

Off-centre loading or poor loading

Adjust chute to place load on centre of belt
Discharge material in direction of belt travel at or near belt travel

Belt running off-centre around the tail pulley and through the loading area

Install training idlers on the return run prior to tail pulley

4.Belt runs off at tail pulley
Idlers or pulleys out-of-square with belt centre line

Adjust idlers in affected area

Material spillage and buildup

Improve loading and transfer conditions
Install cleaning devices
Improve maintenance

Belt running off-centre around the tail pulley and through the loading area

Install training idlers on the return run prior to tail pulley

5.Belt runs off at head pulley
Idlers or pulleys out-of-square with belt centre line

Adjust idlers in affected area

Idler stands not centered on belt

Re- adjust idlers in affected area

Material spillage and buildup

Improve loading and transfer conditions
Install cleaning devices
Improve maintenance

Pulley lagging worn

Replace pulley lagging

6.Belt slip
Sticking idlers

Free idlers and improve maintenance and lubrification

Material spillage and buildup

Improve loading and transfer conditions
Install cleaning devices
Improve maintenance

Counterweight too light

Add counterweight or increase screw take-up tension to value determined from calculation

Pulley lagging worn

Replace pulley lagging

Insufficient traction between belt and pulley

Lag drive pulley
Increase belt wrap
Install belt cleaning devices

7.Belt slip on starting
Counterweight too light

Add counterweight or increase screw take-up tension to value determined from calculation

Pulley lagging worn

Replace pulley lagging

Insufficient traction between belt and pulley

Lag drive pulley
Increase belt wrap
Install belt cleaning devices

8.Excessive belt stretch
Tension too high

Increase speed, same tonnage or reduce  tonnage, same speed
Reduce friction with better maintenance and replacement of damaged idlers
Decrease tension by increasing arc of contact
Reduce counterweight to minimum amount

Counterweight too heavy

Lighten counterweight to value required by calculation

System underbelted

Recalculate belt tensions and select proper belt

Improper belt installation causing apparent excessive belt stretch

run belt in with mechanical fasteners

Improper initial positioning of counterweight in its carriage causing apparent excessive belt stretch

Refer to SIG’s manuals

Insufficient counterweight travel

Contact SIG for verifying minimum distances needed

9.Grooving, gouging or stripping of top cover
Skirt boards improperly adjusted or of wrong material

Install skirt boards with increasing height in direction of belt travel
Use skirt board rubber and not old belt

Belt spanking down under load impact

Install cushion idlers

Material hanging up in or under chute

Improve loading to reduce spillage
Install baffles
Widen chute

Impact of material on belt

Reduce impact by improving chute design
Install impact idlers

10.Exessive top cover wear, uniformly around belt
Off-centre loading or poor loading

Adjust chute to place load on centre of belt
Discharge material in direction of belt travel at or near belt travel

Material spillage and buildup

Improve loading and transfer conditions

Install cleaning devices
Improve maintenance

Dirty,stuck or misaligned return rolls

Remove material accumulations
Install cleaning devices
Use self-cleaning return rolls
Improve maintenance and lubrification

Cover quality too low

Replace with belt of heavier cover gauge or higher quality rubber

Excessive sag between idlers causing load to work and shuffle on belt as it passes on idlers

Increase tension if unnecessarily low
Reduce idler spacing

11.Severe pulley cover wear
Sticking idlers

Free idlers and improve maintenance and lubrification

Slippage on drive pulley

Increase tension through screw take-up or add counterweight
Lag drive pulley
Increase arc of contact

Material spillage and buildup

Improve loading and transfer conditions
Install cleaning devices
Improve maintenance

Bolt heads protruding above lagging

Tighten bolts
Replace lagging
Use vulcanized-on lagging

Material trapped between belt and pulley

Install scrapers on return run ahead of tail pulley

Excessive forward tilt of through rolls

Reduce forward tilt of idlers

12.Longitudinal grooving or cracking of bottom cover
Sticking idlers

Free idlers and improve maintenance and lubrification

Slippage on drive pulley

Increase tension through screw take-up or add counterweight
Lag drive pulley
Increase arc of contact

Material spillage and buildup

Improve loading and transfer conditions
Install cleaning devices
Improve maintenance

Pulley lagging worn

Replace pulley lagging

13.Covers harden or crack
Heat or chemical damage

Use conveyor belts designed for specific condition

Improper storage or handling

Refer to SIG’s manuals

14.Cover swells in spots
Spilled oil or grease, over-lubrification of idlers

Improve housekeeping
Reduce quantity of grease used
Check grease seals

15.Belt breaks at or behind fasteners; fasteners pull out
Tension too high

Increase speed, same tonnage or reduce  tonnage, same speed
Reduce friction with better maintenance and replacement of damaged idlers
Decrease tension by increasing arc of contact
Reduce counterweight to minimum amount

Wrong type of fastener, fasteners too tight or too loose

Use proper fasteners and splice technique
Set up schedule for regular fastener inspection

Heat or chemical damage

Use belt designed for specific condition

Fastener plates too long for pulley size

Replace with smaller fasteners
Increase pulley size

16.Vulcanized splice separation
Tension too high

Increase speed, same tonnage or reduce  tonnage, same speed
Reduce friction with better maintenance and replacement of damaged idlers
Decrease tension by increasing arc of contact
Reduce counterweight to minimum amount

Material trapped between belt and pulley

Install scrapers on return run ahead of tail pulley

Improper transition between troughed belt and terminal pulley

Adjust transition in accordance with  SIG’s Engineering Manual

Pulleys too small

Use larger diameter pulleys

Belt improperly spliced

Resplice using proper method as recommended by SIG

17.Edge wear, broken edges
Bowed belt

For new belt this condition should disappear during  brake-in
In rare cases belt must be straightened or even replaced
Check storage and handling of belt rolls

Off-centre loading or poor loading

Adjust chute to place load on centre of belt
Discharge material in direction of belt travel at or near belt travel

Material spillage and buildup

Improve loading and transfer conditions
Install cleaning devices
Improve maintenance

Belt hitting structure

Install training idlers on carrying and return run

18.Transverse breaks at belt edge
Belt edges folding up on structure

Same corrections as for 1, 2, 3
Install limit switches

Improper transition between troughed belt and terminal pulley

Adjust transition in accordance with  SIG’s Engineering Manual

Severe convex vertical curve

Decrease idler spacing in curve

Increase curve radius

19.Breaks in carcass parallel to edges, star breaks in carcass
Impact of material on belt

Reduce impact by improving chute design
Install impact idlers

Material trapped between belt and pulley

Install scrapers on return run ahead of tail pulley

20.Ply separation
Heat or chemical damage

Use belt designed for specific condition

Insufficient stiffness

Replace with proper belt

Pulleys too small

Use larger diameter pulleys

21.Carcass fatigue at idler junction
Improper transition between troughed belt and terminal pulley

Adjust transition in accordance with  SIG’s Engineering Manual

Severe convex vertical curve

Decrease idler spacing in curve
Increase curve radius

Excessive forward tilt of through rolls

Reduce forward tilt of idlers

Excess gap between idler rolls

Replace idlers
Replace with heavier belt

Insufficient stiffness

Replace with proper belt

Excessive sag between idlers causing load to work and shuffle on belt as it passes on idlers

Increase tension if unnecessarily low
Reduce idler spacing

22.Cover blisters or sand blisters
Spilled oil or grease, over-lubrification of idlers

Improve housekeeping
Reduce quantity of grease used
Check grease seals

Cover cuts or very small cover punctures allow fines to work under cover and cut cover away from carcass

Make spot repair with vulcanizer or self-curling repair material

23.Belt cupping - New belt
Excessive cover gauge ratio

Use a belt with a lower gauge ratio and/or a thicker carcass

24.Belt cupping - Old belt (was ok when new)
Spilled oil or grease, over-lubrification of idlers

Improve housekeeping
Reduce quantity of grease used
Check grease seals

Heat or chemical damage

Use belt designed for specific condition

25.Belt progressive stretch
System underbelted

Recalculate belt tensions and select proper belt

Improper initial positioning of counterweight in its carriage causing apparent excessive belt stretch

Refer to SIG’s manuals

Missing pre-tension before installation

Strictly follow  SIG’s instructions from Installation Guide