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his booklet will help the man in theworkshop when handling Sandvik

steel conveyor belts. The contents aredivided into two parts.

Part 1 deals with installing, joining, andstarting up the belt. The necessaryoperations and their sequences aredescribed. Some sketches will facilitateunderstanding.

Part 2 concerns maintenance.A properly maintained steel belt willgive many years of reliable service.Some tips are given on how problemscan be tackled.

T

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Installing, joining and starting up the steel beltThese instructions are based on Sandvik joining tools for riveted jointsin steel belts with or without tracking V-ropes. See figures below.

1

Belt stretcher

Punching tool and tool kit.

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1. Alignment of end pulleys and belt supportBefore the belt is placed in position on the conveyor the end pulley shaftsmust be aligned horizontally and at right angles to the centre line in thelongitudinal axis of the conveyor.

In the case of belt with tracking V-ropes the tracking sheaves with whichthe tracking V-rope engages must be adjusted in the same plane. Thisis most suitably done by means of a profile wire, arranged as in figure 1.

2 2

Figure 2

b b a b b

Figure 1

If the belt is fitted with more than one V-rope, the tracking sheaves forone V-rope are adjusted as above and then fixed on the shafts. The othersheaves are not fixed until the belt has been mounted and allV-ropes fitted into their tracking sheaves. All idler sets and fixed beltsupports should be adjusted horizontally in the transversal direction ofthe conveyor and approximately 2 mm (5/64 in) below the highest pointof the end sheaves, see figure 2.

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2. Position of the tension frame or tension bearingsIf the conveyor is provided with a tension frame, this is to be placed in theposition shown on the general assembly drawing. If there is no suchdrawing, its approximate position should be as figure 3. The pillow blocks

on the tension frame should be situated in the mean position.

A

Figure 4

A

A3

Figure 3

If the conveyor is fitted with tension bearings, the approximate position

of the pillow block should be as figure 4.

The intial positioning of the tension pulley allows several future rejoin-

ings of the belt without the insertion of an additional belt piece. The steelbelt does not stretch. At the drive end of the conveyor the pillow blocksshould be in their mean position.

Bearings 60 mm A = 12 mm 2 3/8 in. A = 15/32 in.

Bearings > 60 mm A = 25 mm 2 3/8 in. A = 1 in.

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3. Drawing on the beltWhen installing the belt, note the label This side bottom side.

The belt coil should preferably be placed on a roller type support whenit is uncoiled and pulled out over the end pulleys and belt supports of theconveyor. The belt should be drawn on very carefully so that the beltedges and guide or edge ropes are not damaged. See figure 5 a.

In the case of true-tracking belts, they are delivered on wooden drums.The drum, which has a hole in the centre, should be placed on a tubethat will serve as a reel shaft. See figure 5 b.

Figure 5 a

Figure 5 b

Tube/ reel shaft

Wooden drum

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There are two types of riveted joints, overlapped joints and butt strap

joints. Overlapped joints are used as a rule. The butt strap joint isemployed only when an absolutely flat joint is required on the load sideof the belt.

4. Fixing of the belt stretcher

By means of the belt stretcher (see figure 7) the belt is stretched so thatits ends are overlapping one another by at least the width of the punchingtool, and are laid as in figure 6, so as to let the finished overlapping jointpass underneath the belt cleaners and scrapers. For butt strap joint, seeRiveted butt strap joint, item 6, page 13.

Figure 6

Overlap at least the width of the punching tool.

Belt movement

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For belts with tracking V-ropes, recesses are made for the V-rope in theclamps of the belt stretcher.

The belt is stretched so that the sag of the unloaded strand correspondsto the figures given in the table in figure 8. The belt is then stretched tothe minimum permissible working tension, which for a belt without atracking V-ropes is 10 N/mm 2 and for true-tracking belts 7 N/mm 2. Careshould be taken to see that the sag is equal at both edges of the belt, inother words that the belt is level.

Figure 7

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By sighting along the belt edge one can check that it forms a straight line.A stretched wire can be used along one edge of the belt for this purpose.Check that the belt is situated on the centre line of the conveyor.

5. Riveted overlap jointThe following Sandvik tools are used to make a riveted overlap joint: beltstretcher figure 7, punching tool figure 9 and accessories for the punchingtool figure 10. The accessories are supplied in a tool kit which alsocontains rivets.

Figure 8

Figure 9

f

Distance betweensupporting idlers of m 3 4 4 5 5 6 6 7 7 8bottom strand feet 10 13 13 16 16 20 20 23 23 26

Sag of belt f mm 10 20 30 45 60without tracking rope inch 13/32 51/64 1 3/16 1 25/32 2 3/8

Sag of belt f mm 20 30 40 60 80True Tracking Belt inch 51/64 1 3/16 1 37/64 2 3/8 3 5/32

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5.1.Place the punching tool at right angles over the belt ends between theclamps of the belt stretcher. The belt ends must overlap one another byat least the width of the punching tool. Loosen stretching clamps carefullyand check that belt ends do not slip in the punching tool. Remove beltstretcher.

In the case of true-tracking belts, space should be allowed for thepunching tool by preparing V-ropes and the bottom belt end as shownin figure 11.

Figure 10

Figure 11

b = width of punching tool

1 mm (3/64 in.) b 1mm (3/64 in.)

Scribing rule

Punches Snap Countersinktool

Punch lifter

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5.2.Sight along the belt edge and check that it forms a straight line and thatthe punching tool is hanging horizontally. If necessary, adjustment canbe made by carefully loosening the clamp screws at one end of the

punching tool until the desired adjustment between the belt ends isobtained, whereupon the clamp screws are tightened again.

In the case of true-tracking belts care must be taken to see that the endsof the same tracking rope are placed opposite one another in such a waythat the centre line of the V-rope is straight when passing the joint. In thiscase the belt edges at the joint may be slightly displaced in relation to

each other, see figure 12.

Figure 12

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5.3.Place a firm support, e.g. a piece of rigid metal, underneath the punchingtool. Fit the belt stretcher again and stretch so that it absorbs the tensionin the belt.

5.4.First punch the outermost holes at either edge of the belt and let thepunches remain in these holes. Then slightly loosen the clamp screwsof the tool and punch the remaining holes.

5.5.Remove the punching tool. Scribe the correct overlap by use the scribingrule (see figure 10). The studs fit in the punched holes. Shear belt endsalong scribed line.

5.6.Shear corners of belt ends and file them round. Chamfer belt ends. Seefigure 13.

Figure 13

A

A

t

t34

Section A A

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5.7.Countersink rivet holes to a depth of 3/4 of the belt thickness, as in figure13, by means of the countersink tool.

5.8.Rivet the outermost rivets at either edge of the belt and then a rivet inthe belt centre. Continue riveting alternately on both sides of the beltcentre as per the halving method. Ensure that the belt ends are pressedtightly together during riveting.

Spreading the rivets should be carried out as follows:

In the case of true-tracking belts the ends of the V-ropes are preparedas shown in figure 14. Any displacement between belt edges should beequalised, see figure 12.

Figure 14

Width of punchingtool +2 mm (5/64 in.)

5mm(13/64 in.)

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5.8.1. Carbon steel rivetsTap the rivet squarely with a hammer until the rivet shank fills the rivethole. Hammer out the rivet so as to completely fill the countersunk portionof the hole. Round off rivet head with the snap (figure 10).

5.8.2. Stainless steel rivetsStainless steel rivets for belt joints harden easily with hammering.Therefore tap the rivet carefully with light blows until its shank fills therivet hole. File away the hard top surface of the rivet. Then start filling thecountersunk portion with light blows. The thinner the belt, the lighter thehammering. File away the hardened surface again and repeat the

operation, hammering and filing alternatively, at least 3 or 4 times. Roundoff rivet head with the snap (figure 10).

5.9.File rivet heads flush with belt surface if the belt is to be equipped with acleaner or scraper. This filing is most conveniently done with the terminaldrum as underlying support.

6. Riveted butt strap jointThe following Sandvik joining tools are used to make a riveted butt strap

joint: belt stretcher figure 7, punching tool figure 9 and accessories forpunching tool figure 10. The accessories are kept in a tool kit which alsocontains rivets.

6.1.Cut off one belt end at right angles to the belt edge and file it clean whileretaining sharp edges. Stretch the belt according to previous instructions(page 6) so that the belt ends overlap one another by at least a centimetre.

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6.3.Pull the belt ends together by means of the belt stretcher so that theybutt against each other. Check by sighting that the belt edge is straight.

In the case of true-tracking belts the ends of the same tracking V-ropeshould be exactly opposite one another so that the centre line of the V-

rope is straight when passing the joint. In this case the belt edges at the joint may be slightly displaced in relation to one another, see figure 12.

Figure 15

+b+2mm (5/64 in.)

a = see figure 16b = width of punching tool

5mm (13/64 in.)

1 mm (3/64 in.)

6.2.Scribe the unprepared belt edge along the already sheared and filededge. Shear along scribed line and file to accurate fit with the other beltend.

The ends of the tracking V-ropes on true-tracking belts are prepared asshown in figure 15.

a2

a2

b2

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In the case of true-tracking belts, during punching the butt strap is placedon the belt side without a V-rope.

6.5.First punch outermost holes at either edge of the belt in one row of holesand let the punches remain in these holes. Then slightly loosen the clampscrews of the punching tool and punch remaining holes in this row. Fixbutt strap by means of screw clamps before punches in the outermost

holes are removed. Move the punching tool into position for the other rowof holes and punch them.

Figure 16

mmin.mmin.

6.4.Place a strip of belt about 100 mm (4 in.) wide on one side of the belt atthe joint. Place punching tool so that the holes will be in the right positionin relation to belt ends and edges, see figure 16. Place a firm support

e. g. a piece of rigid metal underneath the punching tool.

A

A

t

t

t34

Section A A

Load carryingside of belt

t34

a4

a4

a

t a0.4 0.8 20

0.016 0.032 51/641.0 1.4 32

0.040 0.055 1 17/64

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2 1 3

21 3 1 2

3

Figure 17

1 Locating pieces2 Flat bar3 Flat bar

Section B B

B

BSection A A

A A

6.6.Scribe butt strap. Use the scribing rule (figure 10). The studs fit in thepunched holes. Shear butt strap along scribed lines.

6.7.Clip and file the corners of the butt strap round and chamfer the edgesas shown in figure 16.

6.8.Countersink rivet holes and rivet as per items 5.7.5.9. under the headingRiveted Overlap Joint.

7. Adjustment of idler setsIf the conveyor is equipped with idler sets, these should be adjusted atright angles to one belt edge after the belt ends have been joined. Usinga T-square as per figure 17 is the most convenient way. One leg of theT-square should be placed tightly along the belt edge so that the two

locating pieces are resting on the top side of the belt. The T-square isthen pushed against the idler sets and when all the idler pulleys in oneset or the whole tubular roller is in contact with the other leg of theT-square the idler set is fixed on the conveyor structure.

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8. Starting up and running in the belt

8.1.Check that both edges of the belt have a sideways clearance as shownin the table below. This clearance must not be encroached on by stays,bolt heads or other objects.

Check that all safety devices have been fitted on the conveyor.

8.2.When a steel belt conveyor is first put into operation every precautionshould be taken to protect the belt against any possible damage likely toarise in case the erection and alignment should not be quite correct.

Operators should be placed at all strategic points along the conveyor,especially at the starting switch of the motor so that the power may beshut off immediately if anything is not correct.

8.3.When running in the belt, proceed as follows:

Mark the belt edge at several points, number the points and enter

them in a table. Choose an easily accessible profile of the structure as a referencepoint.

Minimum sideways clearance of the belt edge structure atType of belts belt width mm (inch)

200 300 600 800 1200(8) (12 24) (32 47)

Plain belts 50 75 100(2) (3) (4)

True-tracking belts 25 25 25(1) (1) (1)

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Figure 18

Let the belt rotate and measure the distance between belt edge andstructure when the marked points pass the reference point, figure 18.

Enter measured values in the table as a help for adjusting the endpulleys. See page 19.

Start the belt and let it run a few meters. Then stop it, and check theposition of the belt.

Start the belt again and let it run a few more meters. Stop, and checkbelt position.

Start it again, increasing the distance each time until continuousoperation is achieved.

With variable belt speeds start at the slowest speed and increasegradually to the required operating speed.

Distance of beltedge-structure

Mark P 1

Steel belt

Structure

Reference point

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If more than one reference point is being used, make a table for eachone.

NOTE:Make adjustments only if the belt shows a constant tendency to wanderin one direction.

For example:P 1 = 95 100 98

no adjustment, however, if

P 1 = 96 94 90 85the belt shows a constant tendency to wander and adjustment is requiredas described below.

8.4.If the belt is moving sideways an adjustment of the end pulley bearingsshould be made. Figure 19 shows how the positioning of the end pulleysaffects the sideways movement of the belt. The adjustment screws onthe bearings must not be turned more than a quarter of a turn each time.Mark position of bearing before starting adjustment. Let the belt run fora few rotations so that it will have time to take up a position beforeadjustment is continued.

If the adjustment of the end pulleys is insufficient, the positioning of the idlersshould be checked and may require adjustment as shown in figure 19.

Mark Distance of belt edge-structure in mm at ref. point

P 1 95 100 98 96 94 90 85

P 2 98 103 102 99 97 93 88

P3

97 102 100 98 96 92 87

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Adjusting the shaft of terminal pulleys and idlers.

End pulley (top figure): If angle ( ) is less than 90the belt has a tendencyto move in the direction of arrow a irrespective of the running direction.The shaft is adjusted as per arrows b.

Idler set (bottom figure): If angle ( ) is less than 90 the belt has atendency to move in the direction of arrow a. The shaft should then beadjusted as per arrows b.

The running in of a conveyor should not be considered complete until thebelt has been operating for several hours, first without and then with aload, hot or cold, according to the actual conditions. A reversible conveyormust be run in both directions.

Figure 19

a

a

b

b

90

90b

b

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Maintenance2

1. GeneralThe economy and service-life of a steel belt installation depend on

correct design proper installation operating conditions maintenanceThe frequency of inspections depends on the application and the generalplant conditions.

We recommend periodically checking the following items: Overall condition Belt Pulleys or sheaves Belt support Break points Safety scrapers Tension device

Spring-loaded guide rollers Feeding device Discharge device.

Caution:Before stopping the installation for maintenance, allow all material to bedischarged from the belt.

Make sure that the belt is not started during maintenance by hanging awarning notice on the switch.

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2. Overall conditionsKeep the surroundings of the installation clean.Make sure that pulleys and rollers can rotate freely.Repair or replace worn parts.

3. Trouble shootingThe belt is an essential part of the installation.Here some tips on what can happen and what to do about it.

Problem

Side wandering Pulleys idlersslide barsbreak points

Not correctlyadjusted,contaminated orworn

Clean the items,make sure they arerotating freely,replace worn parts,adjust pulleys andidlers according topart 1, items 8.3.and 8.4.

Unequal temperature overthe belt width.

Ensure that a uni-form temperature isachieved.

Cause Action

o v e r th e w h o le b e lt w id th

uniform te mperature

Burrs at the edges

Due to side wandering the belt hastouched the structure or other rigidobject.

File the belt edges sothat they are round.

Examine belttracking accordingto part 1, items 8.3.and 8.4.

3.1.

3.2.

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Problem Cause Action

Scratches on the load side

Feeding and/or discharge devicesare not operating properly

Repair or replace thedamaged parts

Scratches on the running side

Belt support, safety scraper orother parts in contact with the beltare damaged

Worn or damagedparts need replacing.For adjustment ofidler sets see part 1,item 7.

Wavy edges and/or small blisters in the belt

Uneven temperature. Usually these de-formations disappearat ambient or uniformtemperature. In caseswhere the defor-

mations remain in thebelt, see note, item3.7.

The conditions causingthe damage must becorrected.

Correct Wrong

Section A A

A

A

3.3.

3.4.

Wavy edges Due to side wandering the belt hastouched the structure or other rigidobject. Pressure of belt cleaner orscraper is higher at the belt edgesthan at the middle of the belt.

The damaged edgemust be cut off andthe new edgecarefully filed round.

3.5.

3.6.

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Problem Cause Action

Deformations Pulleys contaminated

Belt support contaminated and/ordamaged

Scratches and abrasion

Material slightly hammers on thebelt at the feeding point

Belt tension too high

Clean pulleys

Clean or replace beltsupport

Check scrapers,rollers or otherobjects in contact withthe belt surface.

Note:Belts with concave orconvex deformations

can be levelled byspecial levellingdevices. Pleasecontact your nearestSandvik office

Loose rivets in the joint

Hairline cracks in welded joint

Normal wear, or feeeding and/ordischarge device incorrect

Normal wear

Loose rivets must bedrilled out and

replaced by newones. If necessary,the whole joint mustbe cut out and a new

joint made. Forinstructions see part1, item 5 or 6.

Note:Use Sandvik riveting

tools. It facilitates thework and enablesaccurate joining.

Contact your nearestSandvik officeregarding repairwelding.

Convex

Concave

3.8.

3.9.

3.7.

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Problem Cause Action

Hairline cracks Fatigue of the belt If the crack is at thebelt edge, a crescent-

shaped piece may becut out

and the edges filedround

cont.

If the crack is not atthe belt edge, smallholes may be drilledat each end of the

crack to prevent itspreading.

Thoroughly removeburrs at the drill holes

3.10.

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Problem Cause Action

If the crack developsfrom the belt edge,

and is so long that thebelt edge cannot becut, a small holeshould be drilled atthe end of the crack.

Fatigue cracks canalso be welded, forfurther information,contact your nearestSandvik office.

When a belt showssigns of fatigue, thepurchase of a sparebelt should beconsidered.

Accidental damage

It may be necessaryto cut out thedamaged section andto splice in a newpiece.

Note:The length of the newsection must not beless than 2/3 of thecircumference of thepulley.

3.11.

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Problem Cause Action

Incorrect belt tension

Temperature variations.

Tension device does notoperate properly.

The specific tension stressis 10 N/mm 2 of belt

crossectional area withplain belts and 7 N/mm 2with true-tracking belts.Check whether the tensionis correct by measuring thesag of the belt between twoidlers in the bottom strand.See part 1, page 8, figure8. Adjust take-up bearings.Check tension device,counterweight or tensionsprings.

3.12.

V-ropes or true- tracking belts worn or loose

V-rope sheaves not correctlyadjusted.Accident.

Adjust sheaves. Preventaccidents. If a new sectionof V-rope needs fixing,contact your nearest

Sandvik office.

3.13.

3.14. CleaningAfter every shift the belt should be thoroughly cleaned, especially beforea longer shutdown. In addition to the installed belt cleaner, cleaning rags,

brushes or, in the food industry, hot water or steam may be used.When using water or steam, ensure uniform heating of the belt over itswhole width. See item 3.1.

Furthermore, also clean all parts which are in contact with the belt. Withtrue-tracking belts or belts with bonded retaining strips the maximumtemperature is + 80C.

Caution:When maintenance is finished, make sure that all safety devices are intheir correct position before restarting the belt!

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