All Portions of Conveyor Belt Running to One Side at a Given Point on Structure
| CAUSE | CORRECTION |
|---|---|
| One or more idlers immediately preceding trouble point not at right angles to direction of belt travel. | Advance, in the direction of belt travel, the end of the idler toward which the belt has shifted. |
| Conveyor frame or structure crooked. | Stretch string along edge to determine extent and make corrections. |
| One or more idler stands not centered. under belt | Center them. Use above technique. |
| Sticking Idlers | Clean & Lubricate with cleaning products |
| Belt runs off terminal pulley. | Check terminal pulley alignment. Check alignment of idlers approaching terminal pulley. |
| Build up of material on idlers. | Build up of material on idlers. Improve maintenance. Install brushes or other cleaning device. |
| Structure not level and belt tends to shift to low side | Level Structure to stop it from sliding and shifting |
Particular Section of Conveyor Belt Runs to One Side at All Points of Conveyor
| CAUSE | CORRECTION |
|---|---|
| Belt not joined squarely | Square the ends and then resplice the belt |
| Cambered belt | Tension it using our belt tension calculator or replace it |
| Worn edge | "Press" the edge |
Conveyor Belt Runs to One Side for Long Distance Along Bed
| CAUSE | CORRECTION |
|---|---|
| Load being placed on belt off-center. | Adjust chute and loading conditions so as to place in center |
| Conveyor frame or structure crooked. | Straighten it. |
Belt is Erratic – Does Not Follow a Pattern
| CAUSE | CORRECTION |
|---|---|
| Belt too stiff to train. | 1. Use self-aligning idlers. 2. Increase tension. 3. Use more flexible belt on replacement. 4. Tilt troughing idlers forward but not over 2°. |
| Combination of causes | 1. Correct loading first. 2. Other causes can be identified and corrected by referring to preceding monograph. |
Severe Wear On Pulley Side of Conveyor Belt
| CAUSE | CORRECTION |
|---|---|
| Slippage on drive pulley. | 1. Increase tension if belt construction permits. Consult belt manufacturer before increasing tension. 2. Lag drive pulley (groove if wet). 3. Increase arc of contact of drive pulley with snub. |
| Spillage of material between belt and pulley, or material builds up at loading point until belt is dragging. | 1. Improve loading conditions with chutes. 2. If belt loaded too full, increase belt speed or decrease feed. 3. Install decking between top and return runs. 4. Install plows or scrapers in front of tail pulley on return run. 5. If fastened belt, change to vulcanized splice to prevent leakage of fines at fasteners |
| Sticking idlers. | Improve maintenance system (update schedule) for cleaning and lubrication |
| Bolt heads protruding above lagging. | 1. Tighten belts. 2. Replace worn lagging. 3. Use vulcanized-on-lagging. 4. Use “slide-lag”. |
| Excessive tilt to troughing idlers. | Adjust to not more than 2° from line perpendicular to belt. |
Excessive Stretch in Belt
| CAUSE | CORRECTION |
|---|---|
| Tension is too high | 1. Increase speed, keeping tonnage same. 2. Reduce tonnage at same speed. 3. Reduce friction with better maintenance and replacing of worn-out and frozen idlers. 4. Decrease tension by improving drive with lagging and /or increased arc of contact. Use counterweight takeup of minimum amount. 5. Use Viking® Conveyor Belt low-stretch construction |
Belt Shrinks
| CAUSE | CORRECTION |
|---|---|
| Belt absorbing moisture. | 1. Put in extra piece, installing with take-up halfway down. 2. Increase tension if belt construction permits. 3. Upgrade top rubber cover with higher elongation grade 1 rubber to resist tears that allow water into carcass. |
Lengthwise Gouging or Stripping of Top Cover
| CAUSE | CORRECTION |
|---|---|
| Skirt board seals too stiff and pressed against belt. | Use more pliable seals (do not use old belting). |
| Excessive space between belt and skirt seals. | Adjust seals to minimum clearance. |
| Metal sides of chute or skirts too close to belt and gap not increasing in direction of belt travel. | Adjust to at least 1” gap between metal and belt and have gap increasing in direction of travel so as to prevent material jamming at this point. |
| Belt spanks down under impact at loading point allowing material to be trapped under skirts. | Install cushion idler to hold belt up against skirts. |
| Material hanging under panel of chute | Improve loading to prevent spillage or install baffles |
| Jamming of material in chute | Widen chute |
Breaks in Carcass Parallel to Belt Edge
| CAUSE | CORRECTION |
|---|---|
| Belt folding back on self. | 1. Realign idlers to center belt. 2. Remove obstructions which cause edge to fold back. 3. Install limit switches to shut off motor in extreme cases of shifting. |
Star Breaks / Transverse Breaks in Center of Carcass
| CAUSE | CORRECTION |
|---|---|
| Material trapped between belt and pulley. | Install decking or guards to prevent spilled material falling on return run. 2. Install plow close to pulley. |
| Impact of lumps falling on belt. | 1. Reduce impact., lower drop height, install rock box, add bafles or grizzly. 2. Use cushion idlers. |
Transverse Breaks at Belt Edge
| CAUSE | CORRECTION |
|---|---|
| Belt edges folding up on structure where it rounds a pulley due to “wander” or pressing too hard against side guard rollers. | 1. Track belt. 2. Provide more lateral clearance. 3. Install limit switches to stop belt in cases of extreme shifting. 4. Remove all side guide rollers. |
| Final idler before head pulley located too close or too high with respect to head pulley. | Adjust idler position in accordance with our expert's conveyor belt recommendations |
| Inadequate convex curve | Adjust curve radius according to our expert conveyor belt specialist recommendations |
Excessive Top Cover Wear
| CAUSE | CORRECTION |
|---|---|
| Dirty, stuck, or misaligned return rolls. | 1. Install cleaning devices. 2. Wash belt. 3. Use rubber disc return idlers. 4. Repair, replace and realign return rolls. |
| Cover quality too low. | Replace with a belt of heavier and/or higher quality cover - GRADE 1 RMA recommendations provided from our conveyor belt experts |
Cover Blisters or Sand Blisters
| CAUSE | CORRECTION |
|---|---|
| Cover cuts or very small cover punctures allow fine particles of “sand” to work under cover and cut cover away from carcass. | 1. Make spot repair with vulcanizer or repair dough, after removing and cleaning underneath all the blister area. 2. Use cut resistant belting from Viking® provided by RW Connection, PRC Industrial or other |
| Oil either in material or from outside source. | 1. Remove source of oil, if possible. 2. Check lubrication. |
Fasteners Pulling Out
| CAUSE | CORRECTION |
|---|---|
| Wrong type of fastener or fasteners not tight | Re-fasten belt with recommended fasteners and set up schedule for regular fastener inspection. Re-tighten new fasteners after a few hours run. |
| Tension too high. | Check tension in belt and if too high, contact our experts for corrections. Use vulcanized splice. |
| Pulleys too small. | Use larger diameter pulleys. |
| Belt carcass too light. | Utilize our conveyor belt experts at Singer with maximum fastener holding ability. Choose a belt with nylon fill/weft. |
Transverse Breaks in Belt Immediately Behind Fasteners
| CAUSE | CORRECTION |
|---|---|
| Fastener plates too long for pulley sizes. | 1. Change to smaller and shorter or hinged fasteners. 2. Increase pulley size. |
Lengthwise Rips Partially or Entirely Through Belt
| CAUSE | CORRECTION |
|---|---|
| Belting running off and snagging on structure. | Track belt. |
| Puncture by tramp iron at chute. | Use metal detector or magnetic remover. |
| Fastener failure. | Consult our experts for replacement belt that is a higher cover grade to resist fastener failure. Offers high fastener holding – abuse resistant. |
Carcass Fatigue at Idler Junction
| CAUSE | CORRECTION |
|---|---|
| Improper transition between troughed belt and terminal pulleys. | 1. Increase transition length. 2. Use transition idlers. 3. Elevate terminal pulley. |
| Severe Convex Vertical Curve. | 1. Decrease idler spacing in curve area. 2. Use transition idlers. 3. Increase curve radius. 4. Remove or lower any elevated idlers in curve area. |
| Excessive forward tilt of trough rolls. | Reduce forward tilt. |
| Excess gap between idler rolls. | 1. Replace with heavier belt. 2. Replace with idlers having maximum gap of 0.4 inches. |
| Insufficient transverse stiffness | Consult our conveyor belt experts to replace with a proper belt |
Belt Fails to Start-Up and Move in Very Cold Weather
| CAUSE | CORRECTION |
|---|---|
| Belt too stiff in construction. | Specify a more flexible belt. |
| Incorrect formulation. | Replace belt with low temperature rubber grade - contact our belt experts |
| Gear oil and bearing grease too viscous for the cold conditions. | Flush out old lubricants and replace with those having proper viscosity for the environmental conditions. |
| Freezing of water penetration | Improve rubber covers to prevent cuts/tears which allows water penetration. |
Product Slips on Incline
| CAUSE | CORRECTION |
|---|---|
| Belt dirty | Clean it |
| Low coefficient of friction (load to belt). | Use a belt construction with a high COF or textured service when replacing and resplicing sections. |
