Assembly of Conveyor Chain

Unless otherwise specified, new conveyor chains are usually supplied in 3m (10ft.) lengths to facilitate handling. The chain is made in even numbers of pitches, with an inner link at one end and an outer link at the other end, so they may be easily joined together.

To connect the chain:

1. First fit the pinholes of the outer link plate to the bushing holes to be connected and insert the pins.

Inserting the Pins

2. Hold the counter plate with a hammer and tap the pin heads with another hammer until the pins are completely inserted into the link plate.

Putting on the Link Plate

3. Insert new T-pins or cotter pins into the bearing pins and bend the ends to prevent loosening.

Inserting T-Pins or Cotter Pins

Note

Do Not Grind the Circumference of the Connector of the Side Bar Hole to Ease Insertion of the Connector.

Do Not Heat Side Bars to Ease Pin Insertion. Side Bar Fatigue may Result Which will Cause the Entire Chain and Bucket Assembly to Fall into the Boot of the Elevator.

Installation of the Chain

Before starting to install elevator chain, the foot shaft take up should be positioned at its upper end of travel to provide for maximum adjustment. To accomplish this, tie off the take up beam assembled in the top of the boot section.

For convenience in shipping and handling, chains are coiled in segments approximately 3 meters long. The chain can become twisted if improperly handled.

Newer pick up the chain by hooking into the center of a coil.

Avoid This

Support the entire coil.

Do This

Do not feed the chain into elevator on its side.

Avoid This

Do This

Assemble and disassemble chain quickly and safely in the elevator with the portable tool.

After the chain connection has been made, check to determine if the joint is too tight, a sharp rap to the cotter end of the pin with a hammer will aid in relieving the tightness. This can be easily accompanied before buckets are attached.

The chain may now be installed in the elevator casing. The chain lengths should be connected together outside the elevator casing and fed in through the boot.

No more than 6 meters of chain should be connected together outside of the elevator during installation, to avoid twisting or bending. Be sure that the chain is oriented properly.

Drop a line into the far-side of casing from the top. Using an air tugger or other means available, feed chain around the bottom of the foot wheel and upward to the top of the head wheel. At this time, tie off the chain, making sure chain is secure. Repeat the same procedure, feeding the chain upward on the opposite side of the casing. Connect chain at the head wheel maintaining firm grip on the chain while making connection. Return to the clean out door and connect the chain. Make last chain connection in boot after chain is installed.

Secure the chain in such a way, using a hoist for tying off to a structural member laid across the bearing angle, so that there is no chance of the chain running away and dropping into the boot. Do not mount buckets to chain until the chain has been installed in the elevator.

It is recommended that all elevators be equipped with a positive stopping device. This feature will eliminate extensive damage to the equipment by preventing a backward action of the elevator.

Chain Installation

Initial Start Up

1. Guards, access doors and covers must be securely fastened before operating this equipment.

2. Electrical interlocks to warn personnel and shut off power whenever discharge of elevator is interrupted.

3. Over load protection, Zero speed protection, Emergency stop switch and all other interlock keep in working condition.

4. Be sure all debris, foreign objects and tools are removed from the elevator inside and adjacent areas.

5. Confirm motor rotation. Ensure it is running in the right direction.

6. Auxiliary equipment feeding the elevator must be electrically interlocked with the elevator to prevent boot flooding when elevator is not in operation.

7. Complete one or two revolution of the chain and buckets by auxiliary drive or manual to check for proper assembly and clearances. If no difficulties are experienced during auxiliary drive rotation, run the elevator with out load for one hours .

Normal Operation

Before start up, make sure there is no obstruction to free discharge of material.

Elevator should be started with empty buckets only. Starting under load places undue strain on chain. Therefore, it is imperative to allow all buckets to empty before stopping elevator.

Stop elevator only after feed has been stopped and elevator allowed to discharge the material.

Successful operation of any elevator is dependent on con feed. Material must be feed at a controlled rate within rated capacity or boot will flood and stall elevator.

Avoid loading buckets to the extent of material spilling back down into the boot section. Boot must not be allowed to pile up with spilled material.

The operator(s) should become familiar with all aspects of the construction and normal operating conditions of the equipments. Thereby, immediately recognizing an abnormal situation or operating condition before serious damage occurs

Maintenance General

Special tools or equipment recommended to maintain or service your elevator chain include a standard torque wrench, portable jack and hammers to be used when checking.

Material should be centrally delivered at the specified uniform rate. Avoid loading buckets to the extend that the material spills back down into the boot section. The boot itself must not be allowed to fill up with spilled material. Chain should be operated at its rated speed.

Chain Check Points

Chain life is generally considered to have expired when the chain does not engage properly with the sprocket / Traction wheel due to damage of its parts or elongation. The chain is usually replaced when this occurs. A long working life without unexpected trouble can be achieved if the chain is properly selected for the conditions of its application. To help prevent premature wear or damage, the following points should be checked.

Points to Observe

1. Abnormal Noise

2. Vibration of the chain

3. Chain rising on the sprocket / Traction wheel

4. Chain winding around the sprocket / Traction wheel

5. Stiff bending of chain, or links

6. Amount and condition of lubrication

7. Whether the chain contacts the case

8. Appearance of the chain. Check for dirt, corrosion, damage on the outside surface of the roller, contact marks, etc. Also check the inside and edge surfaces of the link plate and edge surface of the pin.

9. Damage on the sprocket teeth / Traction wheel surfaces and side surfaces of teeth and engaging area

10.Abrasive stretch of the chain

11.Bending of chain and rotation of roller

Check Points

1. Link Plate

If repeated loads in excess of the allowable load are applied to the chain, there is a strong possibility of fatigue breakage of the link plate. Fatigue breakage is difficult to anticipate until a crack is produced. Usually a crack develops at the edge of a hole or at the side of the link plate, as shown in the illustrations below. The presence of cracks should be checked carefully. Continuous checking can prevent accidents.

Positions where cracks are likely to develop

Example of an expanding crack

2. Roller

Care should be taken to avoid repeated impact loads over the allowable load as fatigue breakage may occur. The roller should be checked in the same way as the link plate. If foreign objects interfere with the engagement of the roller and sprocket, the roller may be damaged and a crack may develop. Careful attention should be paid to this. Chains damaged due to fatigue breakage must be completely replaced.

3. Sprocket

Chain and sprocket engagement can be checked by observing the roller and tooth surfaces. The proper margin (A) and improper margin (B) are shown in the fig. The installation should also be checked. The normal area where wear will occur is slightly above the bottom of the lowest point between the sprocket teeth. If tension remains on the slack side, the roller will slightly touch the lowest point between the sprocket teeth. When an idler or tightener is used, wear will occur almost directly between the sprocket teeth.

Areas to Check for Sprocket Wear

Maintenance Check Point

Check Points Comments

Centering

A high precision guide rail is essential to ensure proper centering of the conveyor. If centering is not accurate (with no side guide rail), the conveyor chain will wobble and weave resulting in shorter conveyor chain life.

Sprocket alignment

When two or more sprockets are installed in a row, be sure to align the position of the sprocket teeth. If the sprocket teeth are not properly aligned, the working load will not be equally divided and will cause the chain to twist.

Take-up If take-ups on both sides are uneven, the conveyor chain will not engage smoothly with the sprocket.

Initial chain tension Maintain adequate chain slack. If chain tension is too high, loss of power will result. This is a dangerous situation and if too loose, the chain will climb the sprocket.

Trial run

An unloaded trial run should be conducted after installation by switching the system on and off several times intermittently. After inspection, continuous operation may begin.

Stopping the conveyor The conveyor should be stopped when it is not loaded, otherwise the conveyed material may cause an overload when the conveyor starts again.

Lubrication

Except for conveyor chain like the Flow Conveyor, which runs without lubrication, conveyor chain should be lubricated periodically. Lubrication of the reducer, bearing, and driving roller chain is also essential.

Securing conveyor parts Parts fastened to the conveyor such as buckets, aprons, slates, etc. are apt to loosen due to vibration. Pay careful attention to fastening nuts and bolts securely. Be sure to check periodically.

Amount of chain slack Regularly check and adjust the amount of chain slack.

Temperature and prevention of freezing

When differences in temperatures (summer and winter or between day and night in the winter) are very severe, conveyor damage may occur. Under these circumstances, operate the conveyor carefully taking any variations in

temperature into account.

Record of conveyor use and maintenance

After installing the conveyor, prepare a record of the expected capacity to be conveyed, the conveyor's speed, and r.p.m. of the main shaft, electric current, voltage, working hours, actual conveying capacity, inspection date, lubricating date, details of trouble, etc. This will serve as protection against unexpected accidents. This record will also be convenient for maintenance and repairs.

Preventive Maintenance

Once the elevator is placed in operation, Preventive maintenance program should begin.

1. The buckets should be checked periodically for loose bolts and build up of material. All damaged buckets should either be repaired or replaced to eliminate material falling into the boot.

2. Check the rubber lip or tongue plate on the discharge spout of the elevator, which should not touch with the bucket.

3. Check take up of bucket clearance with bottom of boot.

4. Side bars inner surfaces should be checked for wear. This is an indication of misalignment.

5. Loose or unseated pins are danger signals and could lead to a sudden and unexpected chain shut down.

6. Excess material building in the chain and attachments could cause improper seating on traction wheel rims / sprockets and rough elevator operation.

7. Round parts in chain; that is, the pins and bushings should be inspected for wear.

8. Traction wheel / Sprockets should be inspected for alignment and excessive wear.

Weekly Inspection (once in 175 Hrs )

1. Check motor load.

2. Check bucket fixing bolt missing & looseness.

3. Check boot for material build up and clean.

4. Check material build up in chain components and hammer it so that it can dislodge.

5. Check chain for connecting pin seating.

Quarterly Inspection ( once in 2000 Hrs )

In addition to weekly inspection points, following pointes are to be checked

1. Check inside block links for wear

2. Check all side bars on bushing OD for wear.

3. Visually inspect clearance between each set of inner and outer side bars. Excessive clearance suggests pin fracture.

4. Check for loose segmental fasteners. Check torque values for segmental rim bolts.

5. Check segmental traction wheel unusual wear.

6. Check for loose or missing buckets.

7. Inspect and adjust tongue plate at discharge point for wear and replace if excessively worn.

8. Check gravity take up guides and stop blocks; check for free operation of take up guides, check for evidence of wear on guides.

Annual Inspection ( Once in 8000 Hrs )

In addition to weekly & Quarterly inspection points, following pointes are to be checked.

a) Traction wheel / Sprocket

1. Check for loose or missing segmental fasteners and torque values. If fasteners are missing, replace with proper diameter high strength type.

2. Check for evidence of axial movement of sprocket along shaft.

3. Check for evidence of unusual or excessive wear and replace sets of segments as required.

b) Gravity Take up

1. Check stop blocks; check for free operation of take up in guides; check for evidence of wear on guides.

c) Buckets

1. Check for loose or missing bucket fasteners.

2. Check for unusual wear patterns or damage buckets.

d) Drive station

1. Check head shaft bearings for evidence of wear.

2. Check foot shaft bearings and sleeves for evidence of wear.

e) Chain section

1. Check all side bars and bushing OD s for uneven or deep wear patterns.

2. Check inside blocks for unequal wear from traction wheel / Sprocket.

3. Check chain for missing T- pin.

4. Check for chain elongation wear.

5. Remove 5 or 10 pins at random and measure the pin OD and bushing ID. Hammer test all pins for soundness.

Chain Tension

Adjustment of Chain Tension

The correct amount of chain slack is essential for proper operation of the chain. When the chain is too tight, working parts such as chain, sprocket wheel, shaft, bearing, etc. carry a much heavier load. On the other hand, too much slack is also harmful and causes the chain to climb the sprocket teeth.

Frequency of Adjustment

The chain has a tendency to stretch a certain amount at the beginning of operation due to slight distortion of its component parts. After such initial elongation, the chain stretches slightly, but constantly, by normal wear. To maintain proper chain tension, adjustments, if necessary, should be made at regular intervals. Neglect of careful inspection increases the chance of an accident.

Frequency of adjustment:

1st week - once a day

2nd ~ 4th week - twice a week

Thereafter - twice a month

Note:

The above frequency schedule is based on 8 hours operation a day. When working hours are increased, the frequency of adjustment should be increased accordingly.

Even Adjustment of Take -up on Both Sides

This can be easily accomplished when take-ups are cooperating screw type or counterweight type. Where two parallel chains are adjusted by two independently operated take-ups, care must be taken to ensure even stroke on both the left and right side. An uneven adjustment will cause the link plate and the side of the sprocket teeth to interfere with each other and result in an overload condition.

Chain Pitch Elongation

When the chain engages with the sprocket or runs on a curved rail section, the chain flexes causing the chain to stretch. In most cases, this is due to wear of the bearing parts such as the pins and bushings. As chain pitch elongation increases, the chain tends to climb the top of sprocket. This makes smooth operation of the conveyor impossible. The limit of pitch elongation is generally 2% - 6 % of the chain pitch.

Places to Measure Chain Elongation

Fig. indicates the way to measure chain pitch. Using a steel tape measure, measure as many pitches as possible (at least 4 pitches required). Measuring points should be properly determined according to (A), (B) or (C) in Fig., depending on the wear condition of the conveyor chain. The chain pitch elongation per link is to be computed by comparing the actual pitch measured against the original chain pitch.

Chain Pitch elongation can then be calculated.

Chain Elongation = Measured Length - Std. Length x 100(%) Standard Length

Standard Length = Chain Pitch x Number of Links

Note

When measuring, use at least 6 to 10 links to help keep any measuring error to a minimum. When measurement cannot be done with a vernier, it is possible, though less accurate, to use a tape measure. If a tape measure is used, the measured length should be as long as possible.

Life of Chain and Sprocket

After a certain period of time, wear will eventually appear on the chain and sprocket. The life of conveyor chain depends on the wear of each component part and on pitch elongation. Careful inspection is required more often than for power transmission roller chain.

The life of the conveyor chain component parts is shown below. TIDC recommends that periodic inspections of the wearing parts are conducted and that care be taken to ensure that proper maintenance is carried out. Also, a schedule for changing the chains should be established.

Roller Life

When wear between the rail, bushing and roller causes the under surface of the link plate to contact the rail, the chain has usually reached the end of its usability. As shown in Fig, when the link plate starts contacting the rail, rolling contact suddenly turns into sliding contact between the link plate and rail, resulting in greater wear, an increase in chain tension and a reduction in transmitted horsepower. Such wear generally appears on horizontal or inclined apron conveyors, slat conveyors, etc.

Where a curved section of rail is provided, the allowed wear amount is decreased by a dimension equivalent to "S". More care must be taken to observe wear than with horizontal sections.

The chain life has expired as soon as holes or crevices appear on the rollers due to wear.

Bushing Life

Bushings are generally useable until holes appear. Holes may appear as a result of conveying very abrasive materials such as iron ore powder, coke, etc.

Link Plate Life

Reciprocal friction between inner and outer link plates and contact between side surfaces of rollers and inside surfaces of link plates causes wear as indicated by (A) and (B) in Fig.

If the amount of wear exceeds 1/3 of the original plate thickness, the tensile strength of the chain will be reduced. When link plate wear appears faster than wear of other component parts, misalignment of the conveyor during installation is the cause in most cases. Misalignment can also develop during operation of the conveyor. Therefore, careful inspection is required to ensure maximum working life.

Please check the following items:

1. Correct alignment of driving and driven sprockets

2. Correct alignment of shafts in horizontal and vertical planes

3. Preciseness of level gauge and accurate leveling

Sprocket Life

When the sprocket is worn, the chain tends to cling to the sprockets and vibrate. The amount of allowable wear depends on the conveyor type and chain size, but generally, wear to a depth of 3mm (0.12") to 6mm (0.24") is a sign that the existing sprocket should be repaired or replaced with a new one to ensure continued chain life. One of the following means may be used to extend sprocket life:

1. Cut section (A) shown in Fig. with a grinder

2. Reverse the sprocket to change the engaging area of the tooth

3. Surfacing can be made using a welding rod to obtain the correct tooth profile. However, it is more effective to replace the existing sprocket with a new one.

If the sprocket teeth are worn as shown in Fig. , the alignment of the sprockets may be incorrect. Proper axial alignment of the sprockets will help reduce or even eliminate this type of wear.

Sprocket wears

Wear Characteristics of Conveyor Chain

Mechanical wear

When conveyor chain is used under reasonable conditions and a normal atmosphere, mechanical wear causes the bearing surface of the chain to shine brightly. With proper lubrication, further life can be assured.

Wear caused by conveyed material

Material having excessive wear characteristics tends to stick to the chain and to wear the surface of the chain due to reciprocal friction between the material and chain. Under such conditions, care should be taken to prevent material from falling on the chain. For extra protection, chains should have higher wear resistant specifications.

Wear due to corrosion

Conveyor chain used in applications where acidic or alkaline chemicals are present, will be subject to corrosive wear as well as mechanical wear. To protect against the chemical corrosion accompanying mechanical wear, stainless steel is recommended.

Electrochemical corrosion

When the chain is splashed with water, and then enters chemical solutions, the surface of the sliding area (i.e., Pin/Bush, Bush/Roller) is exposed to electrochemical corrosion, one of the most damaging types of corrosion.

Troubleshooting and Problem Solving

Symptom Possible Causes Remeady

Excessive wear at the inside of the chain's link plates or the teeth surface

Improper centering of the sprocket

Remove the chain and correct the centering of the drive and driven sprockets

.The chain is being pushed to the side

Remove the cause of the push and/or install a guide roller

.

Vibration caused by the inaccurate finishing of the sprocket's axle hole

Check and correct the faulty locations and replace the sprocket with a new part

Improper flex or bending of the chain

Rusting or corrosionInstall a partition to protect the chain or select a chain of suitable specification

When the chain is splashed with water, and then enters chemical solutions, the surface of the sliding area (i.e., Pin/Bush, Bush/Roller) is

Particles of the conveyed material have contaminated the pin, rolleThis Manual Contains Instructions for maintenance of TIDC chains. The reliable operation and long service life of these chains depends to a greater extend on the care taken during

Install a partition to protect the chain. Select a chain with large clearance between the pin, bushing and roller.

exposed to electrochemical corrosion, one of the most damaging types of corrosion.

.

installation and operation and the degree of maintenance.

Safety is a factor that must be considered at all times in the operations and mechanical equipment. Use of proper tools and methods can prevent serious accidents that may result in injury to the operators and fellow workers.

Warning

Failure to Observe and Follow all Safety Instructions may Result in Serious Personal Injury or Property Damage.

Use care to prevent injury, Comply with the following to avoid serious personal injury

1. Guards must be provided on all chain and sprocket installations in accordance with provisions of ANSI/ASME B15.1 - 1992 "Safety Standards for Mechanical Power Transmission Apparatus," and ANSI/ASME B20.1 - 1993 "Safety Standards for Conveyors and

Related Equipment," or other applicable safety standards. When revisions of these standards are published, the updated edition shall apply.

2. Always lock out power switch before installing, removing, lubricating or servicing a chain system.

3. When connecting or disconnecting a chain:

a) Eye protection is required. Wear safety glasses, protective clothing, gloves and safety shoes.

b) Support the chain to prevent uncontrolled movement of chain and parts.

c) Use of pressing equipment is recommended. Tools must be in good condition and properly used.

d) Determine correct direction for pin/rivet removal or insertion.

e) Steady force, such as mechanical or hydraulic press, is preferred. If impacting force such as hammer is used, take special precautions to avoid metal chir, and bushings. Otherwise, contamination from foreign particles.

.Deformation of the chain caused by improper installation

Inspect and correct the installation of the sprockets and axles

.Inadequate lubrication

Inspect the lubrication or look into wear resistant chain

.Operation in extremely high temperatures ( Over 400 c )

Provide adequate clearance.

.Seizure from excessive loads

Provide periodic lubrication. Reduce load

.Pin bending due to excessively high loading

Reduce load.

The chain is winding on the sprocket

Too much slack in the chain.Adjust the chain length or distance between axles, or install a tensioner.

.Excessively worn sprocket. The chain and sprocket do not match.

Replace the chain and / or sprocket with a correct sized part.

The chain is climbing up on the sprocket

The chain and sprocket do not match.

Replace the chain and / or sprocket with a correct sized part.

.

The total arc of contact with the chain on the sprocket is insufficient.

Have the total arc of contact be at least three teeth on the sprocket

.Excessive load.

Reduce the load by installing a shock absorber

.Inadequate back - tension

Adjust the catenary or take up idler, or install a tensioner

.Excessive elongation of the chain due to wear

Replace with a new chain

.

The distance between the center of the chain and sprocket do not match

Inspect and correct

Unusual noisesInadequate lubrication to the connecting portions of the pin and bushing

Provide sufficient lubrication

.

Inadequate lubrication to the connecting portions of the bushing and roller

Provide sufficient lubrication. Use a bearing roller or plastic roller

.Winding or rising on the sprocket See previous symptom

.Loose chain casing or axle bearing

Tighten all nuts and bolts

.Interference of the casing with the chain or other moving part

Inspect and correct

.Excessive wear in the chain or sprocket

Replace the chain or sprocket

.Improper setting of the guide rail Inspect and correct

Rusting of the chain Inappropriate selection of material

Select a more suitable chain material. Protect the chain from the environment. Apply a rust inhibitor

.Condensation

Eliminate the temperature difference between inside and outside of the conveyor using insulation etc

Improper roller spin and uneven roller wear

Excessive load on rollerProvide sufficient lubrication. Consider bearing roller

.

Particles of the conveyed material, or other foreign particles, have gotten between bushing and roller

Periodic cleaning. Install partition to protect chain

.

Particles of the conveyed material, or other foreign particles, have build up on to the rail

Periodic cleaning. Install partition to protect chain

.

The lubricant is falling on the roller surface and rail with out entering between the bushing and roller, and between the roller and link plate

Select the appropriate lubricant and lubrication method

.The bushing and roller have rusted together

Select the appropriate specifications

.The inner plate is moving sideward

Replace with a new chain. Re inspect the installation and load conditions

When the chain is splashed with water, and then enters chemical solutions, the surface of the sliding area (i.e., Pin/Bush, Bush/Roller) is exposed to electrochemical corrosion, one of the most damaging types of corrosion.

.

The bushing is crackedReduce the load and lower the speed of rotation

.

The side surface of the roller is contacting the side of the link plate due to a thrust load

Eliminate the cause of the thrust load

.The chain and sprocket do not match. Excessively worn teeth

Check for tooth deformation

The roller is opening up

Excessive loadReduce the load, provide adequate lubrication, remove any large steps in the rail

The roller or bushing is split (falling off )

Excessive loadReduce the load. Provide adequate lubrication.

. The number of teeth is too few Increase the number of teeth.

with respect to the conveyor speed Decrease the speed

The roller is becoming hour glass shaped

Excessive load or inadequate lubrication

Increase the lubrication, improve loading conditions, and replace the chain with a new one

.Excessively worn rail Correct or replace the rail

The chain sticks and slips. (This can be caused by a combination of many problems. Therefore, the listed remedies may not solve the problem)

Change the rolling friction coefficient of the chain

Lubricate the chain and clean the rail. Change to a bearing roller chain

.The conveyor speed is too slow Increase the speed

.

Insufficient rigidity in the frame. The conveyor chain is small compared to the device

Increase the frame rigidity, increase the chain model number. Decrease the slack in the drive roller chain

.The force of friction is excessively large

Lubricate the chain. Change to a bearing roller chain.

.The machine is too long

Divide the conveyor system into sections to decrease the length

.

Inconsistent speeds due to movement along a polygon - shaped path

Use a 12 or more toothed drive sprocket

Excessive wear of the sprocket teeth valleys and drive sides

Excessive worn teethReplace both the chain and sprocket

.Insufficient number of teeth Increase the number of teeth

.Roller chain is not being used Use roller chain

.

The hardness of the teeth is insufficient with respect to the load and conveyed material or foreign particles

Use a sprocket with hardened teeth or changeable teeth

.The Chain and sprocket do not match

Replace the chain or sprocket with one that is of the correct size

Excessive wear of the inside link and pin on one side

Increased internal tension when meshing with the sprocket

Attach the supporting block to the sprocket. Reduce the load. Lubricate the chain and sprocket.

Sudden fracture of the link plate

Excessive load

Eliminate causes of the overloading. Install a safety device ( fro example shock relay) Increase chain size

.Weakening of chain caused by excessive wear of corrosion

Replace with new part. Install a cover to protect the chain. Periodically lubricate chain. Select a chain with the proper specifications for the application.

.The link plates are pressed outward by the sprocket

Check and correct the installation. Excessively worn chain or sprocket. Check the chain and sprocket match, and correct as necessary.

Crack in the link plate (1) fatigue breakage

Excessive load or excessively large repetitive load

Eliminate overloading or large repetitive loads

.The factor of safety is not sufficient

Increase the size or specifications of the chain to increase the factor of safety. Replace with a new chain.

.Repetitive load on attachment

Eliminate overloading or large repetitive loads; Increase the chain size to increase the allowable load of the attachment.

( 2 ) Corrosion stress The chain is being used in an Install a cover to protect the

crack. ( Bow shaped crack in heat treated metal pieces )

acidic or alkaline environment. ( This is not caused by a repetitive load )

chain from the environment. Replace with new part. Use a chain with a high resistance to corrosion stress cracks.

Deformed link plate holes and pin rotation ( the pin is shifted from its normal position )

Excessive loadEliminate the cause of overloading and replace chain with a larger size

.Improper installation of the connecting link

Replace connecting link with a new one.

.Excessive load and inadequate lubrication

Replace with a new chain and improve the lubrication and loading conditions.

.

Seizure of the pin and bushing, improper bending or flex of the chain

Increase the chain size. Increase the clearance between the pin and bushing.

(1) Pin fatigue failure (2) Pin corrosive fatigue (3) Pin brittle fracture (4)Pin sudden fracture

The factor of safety used for calculation of the peak load versus the breakage load was too small. The peak load acted like a repetitive load on the chain.

Recheck the size of the peak load, and eliminate its cause. Replace the chain with a large pin diameter.

.

The pin was subjected to a tensile load at the side of the fracture origin, where the break then progressed. Chain is especially susceptible to this when the pin surface is corroded and weak against bending stress.

Recheck the size of the peak load, and eliminate its cause. Replace the chain with a large pin diameter. Use a pin of anti - corrosive material.

.Poor environment Use an appropriate pin material

.Excessive load

Eliminate the cause of overloading, and replace chain with a larger size.

Excessive wear caused by the conveyed material. The surface is worn away.

The chain is exposed to acidic or alkaline substances, and , therefore, more susceptible to machine wear, which then progresses much faster.

Prevent material from falling onto the chain. Use a wear resistant chain.

Excessive wear from corrosion. Link plates not made from an anti corrosive material are corroding.

The chain is exposed to acidic or alkaline substances, and , therefore, more susceptible to machine wear, which then progresses much faster.

Use a material not affected by the chemicals. Use a wear resistant material for the machine worn parts.

Excessive wear from electro chemical corrosion. Only the contact surfaces are worn.

When the chain is covered with water or passes through a solvent, the portions in contact suffer galvanic corrosion.

Use a material not affected by the chemicals. Use a wear resistant material for the machine worn parts.

Safety Precautions

This Manual Contains Instructions for maintenance of TIDC chains. The reliable operation and long service life of these chains depends to a greater extend on the care taken during installation and operation and the degree of maintenance.

Safety is a factor that must be considered at all times in the operations and mechanical equipment. Use of proper tools and methods can prevent serious accidents that may result in injury to the operators and fellow workers.

Warning

Failure to Observe and Follow all Safety Instructions may Result in Serious Personal Injury or Property Damage.

Use care to prevent injury, Comply with the following to avoid serious personal injury

4. Guards must be provided on all chain and sprocket installations in accordance with provisions of ANSI/ASME B15.1 - 1992 "Safety Standards for Mechanical Power Transmission Apparatus," and ANSI/ASME B20.1 - 1993 "Safety Standards for Conveyors and Related Equipment," or other applicable safety standards. When revisions of these standards are published, the updated edition shall apply.

5. Always lock out power switch before installing, removing, lubricating or servicing a chain system.

6. When connecting or disconnecting a chain:

a) Eye protection is required. Wear safety glasses, protective clothing, gloves and safety shoes.

b) Support the chain to prevent uncontrolled movement of chain and parts.

c) Use of pressing equipment is recommended. Tools must be in good condition and properly used.

d) Determine correct direction for pin/rivet removal or insertion.

e) Steady force, such as mechanical or hydraulic press, is preferred. If impacting force such as hammer is used, take special precautions to avoid metal chips from the chain or tools.