Page 8 - ConveyorBeltMaintenanceManual2010

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INSTALLATION, MAINTENANCE & TROUBLESHOOTING GUIDE
i n s t a l l a t i o n
Certain basic statements and recommendations can be made about tensioning for splicing:
• Belts which are tensioned by pulling in only one direction require more splicing tension than those pulled in both directions.
• Slope belts spliced at the top of the slope require more splicing tension than those spliced at the bottom.
• Slope belts with an anti-rollback device that cannot be released must be tensioned by pulling only in the direction of
belt travel.
• Check the belt frequently during tensioning to ensure that the belt is free and not binding at any place.
• During the final tensioning pull, be sure the ends of the belt are lined up properly.
Conveyor installations having limited take-up travel should be spliced to a tension based on the loaded running tension. This
tension should be specified by Goodyear Engineered Products and measured by suitable load cells or dynamometers. Where it
is practical, fabric belts should be run for several weeks with mechanical fasteners before making the final vulcanized splice.
Obtaining the required tension depends heavily on the experience of the individual making the splice. It is possible for a gravity
type take-up to severely damage the conveyor structure if it is positioned too close to the forward or upward stop. Too much
tension applied to a relatively short belt may thus have a harmful effect on the pulley shafts and bearings as well as the belt.
The belt may be tensioned with a suitable take-up device as follows:
When the counterweight is on: Tie the take-up off 6” to 8” (150mm to 200mm) above the desired running position
(Consideration may have to be made for excessive sag). Next, pull the belt until the take-up starts to lift and the tie-off ropes
become slack. Make the final splice, allowing a minimum of belt slack.
When the counterweight is not on: Splicing without the counterweight installed is undesirable; however, the following procedure
should be employed if necessary: Use suitable belt clamps to hold the take-up pulley 6” to 8” (150mm to 200mm) above the
desired running position (Consideration may have to be made for excessive sag). Pull the belt to its running tension, which
can only be estimated in this situation. Judgment in estimating this tension will improve with the experience of the splicer.
Tables 1-1 and 1-2 show the recommended take-up travel and initial take-up position respectively.
TYPE OF TAKE-UP AND
CARCASS MATERIAL [WARP]
PERCENT OF RATED TENSION
TABLE 1-1
RECOMMENDED MINIMUM TAKE-UP TRAVEL
IN PERCENT OF CENTER DISTANCE*
MANUAL TAKE-UP**
AUTOMATIC TAKE-UP
NYLON
POLYESTER
ARAMID
FIBERGLASS
4.00%
2.50%
2.00%
1.00%
100% 75% 50% or LESS
3.00%
2.00%
1.50%
0.75%
3.00%
1.70%
1.50%
0.50%
0.30%
*For [1] belts installed at average empty running tension [2] take-up position per Table 1-2, and [3] Drive location
at or near the high tension end of the conveyor.
**Only short endless feeder belts and the like would normally be vulcanized on conveyors with a manual take-up.
2.50%
1.25%
1.00%
0.40%
1.23%
2.00%
1.50%
1.00%
0.50%
1.50%
0.75%
0.75%
0.25%
0.15%
NYLON
POLYESTER
ARAMID
FIBERGLASS
STEEL