Steel Wire Ropes. Handling Classification Security Factors Uses and Recomendations. Cables.indd 1 27/09/ :00:12

Transcription

1 Steel Wire Ropes Handlg Classification Security Factors Uses and Recomendations Cables.dd 1 27/09/ :00:12

2 Steel Wire Ropes Wire Rope is made up of steel wires, generally braided a helix (spiral) formg units known as strands. The strands the wire rope can vary accordance with specific and desired properties. Wires Wires are produced by reducg the diameter of the base wire, after passg through a series of dies and formers while have an axial force applied to it. The wire s properties depend on its chemical composition, microstructures, gra size, segregations and process conditions. Wires comply with the required ASTM A 1007, JIS G 3525, API 9 A, RRW 410 F, ISO 2232 and other ternationally recognized standards. Strands Strands are formed by wires of the same or different diameters, twisted over a central core. Core The core or nucleus is the central axis of the wire rope, around which strands are wrapped. We use various cores, cludg steel, natural fiber or synthetic. Dimensions and Tolerances The cable diameter complies with the tolerances established the followg table: Wire rope Diameter mm or. 10 (3/8 ) >10 (3/8 ) % Tolerance TABLE 1 No Load 5% MBL 10% MBL Diameter Measurement Wire Rope Group of strands twisted helically around a core or nucleus. The wire rope and its Components: Wire Strand Core CORRECT METHOD INCORRECT METHOD Correct Method: Place the measurement device on the widest part of the wire rope. Incorrect Method: This is not the wire rope s widest diameter. 2 Cables.dd 2 27/09/ :00:12

3 Steel Wire Ropes Lay length The lay of a steel wire rope is determed by the form which the strands are rolled the wire rope and the way the wires are rolled the strands. RIGHT REGULAR LAY Wires parallel to the wire ropes axis The length of lay of a steel wire rope is the learly measured distance, from one pot of the strand to another pot on the same strand, after completg a pass around the core of the wire rope (360 ). PASO REGULAR DERECHO Strands diagonal towards the right Accordg to the direction of the strands over the core, they can be to the right or the left. Accordg to the direction of the wires the strands and the rollg of these over the core, the wire rope can be of two types: regular lay or lang lay. These can also be rolled to the left or right. LEFT REGULAR LAY Wires parallel to the wire ropes axis Regular Lay: The position of the wires the strands is opposite to the direction of the wire rope, see followg figures. This type of configuration allows the wire rope to be compact, well balanced and with excellent stability. PASO REGULAR IZQUIERDO Strands diagonal towards the left Lang Lay: The position of the wires the strands provides it with the same direction of all the strands with the wire rope. This provides excellent fatigue resistance as well as resistance to abrasion damage. RIGHT LANG LAY Wires diagonal to the wire rope axis Strands diagonal towards the right LEFT LANG LAY. Wires diagonal to the wire ropes axis Strands diagonal towards the left 3 Cables.dd 3 27/09/ :00:14

4 Steel Wire Rope Handlg 1 Installation To stall the wire rope a wch or drum, it s advisable to follow the followg structions: Before stallg a new wire rope, the pulleys and drums should be checked to sure they have no degradation or defects. When a degradation or defect is found the pulley and/or drums, this should be replaced with new ones, matchg the profile and diameter of the new wire rope. Rotatg or rotatg the free end of the wire rope can cause the de-braidg of the wire rope. 3 Storage The termals and/or accessories cannot be removed or stalled without makg sure that the twist is mataed. The wire ropes should not be stored places that emit corrosive vapors and should not be contact with the floor. 2 Transport 4 Matenance This transportation operation should be performed such a way as to completely avoid any possible of contact of between the wire rope and loadg equipment. Matenance should be comprised of spections, lubrication and cleang with regular frequency. Defects or irregularities should be noted and rectified. The spection should always clude the startg pot of the wire rope as well as its stalled. The spection should always clude the settlg up of the termals, with emphasis on the pot of entry. 5 Lubrication 4 An adequate lubrication prolongs the useful life of a wire rope because it reduces corrosion and abrasion caused by the friction of the wire rope agast the pulleys. The frequency of lubrication depends on the followg factors: Retaed lubrication from the manufacturg process Elevator use Security factor and workg temperature Cables.dd 4 27/09/ :00:14

5 Steel Wire Rope Handlg 6 Manipulation INCORRECT FORM CORRECT FORM 5 Cables.dd 5 27/09/ :00:21

6 Steel Wire Ropes Classification Steel Wire Ropes are classified by diameter, number of strands, type of core and construction. 4. Warrgton Strand The types of strands wire ropes are: 1. Simple cap common Strand TORON 1X25 This strand is characterized by havg an exterior cap formed by wires of two different diameters, alternatg their position the crown. The type of strand most commonly used is 1+6+6/6=19 TORON 1X7 The most common example of simple lay strand. Construction is comprised of seven wires. It has a central wire and six wires of the same diameter that revolves around it. The most common composition is 1+6=7. 5. Warrgton Seale Strand 2. Seale Strand This is a combation of the previous two strands and combes their best qualities: The conjunction of fe terior wires allows for flexibility, while the exterior cap of wider diameter wires, gives resistance to abrasion. The most common construction is 1+7+7/7+14=36 TORON 1X19 Construction which the last layer contas the larger diameter wires than the terior strand, givg the strand more resistance to abrasion. The most common composition is 1+9+9= Filler Strand TORON 1X26 6x26 steel cable combes resistance to flexg and abrasion, givg good wire live durg usage 1+5+(5+5)+10=26 TORON 1X26 This strand is distguished by havg fe threads that fill the existg spaces between two wire layers. This type of strand is used when a large metallic section wire rope is required with a good resistance. The most common composition is 1+6/6+12=25. Most Common Wire Rope Constructions The physical and mechanical properties of the different constructions that EMCOCABLES manufactures are detailed the followg tables. These are taken usg the ASTM 1023 standard. 6 Cables.dd 6 27/09/ :00:22

7 Classification CABLE 6X7 ALMA DE FIBRA (AF) 6x7 Fiber Core (FC) Wire Rope Construction Strand Construction Item Quantity Item Quanitity Strands 6 Wires 5 to 9 External Strands 6 External Wires 4 to 8 Strand Layer 1 Layer Wires 1 Wires 30 to 54 table 2 Diameter Approx Weight Mimun Break Load Diameter Range mm lb/ft kg/m IPS tons 1770 kn EIP tons 1960 kn M / / / / / / / / / / / / / IPS = Improved Plow Steel EIPS = Extra Improved Plow Steel For ton/mt Multiply by For kg/mt Multiply by Max 7 Cables.dd 7 27/09/ :00:22

8 Classification CABLE 6X7 ALMA DE ACERO (AA) 6x7 Steel Core (SC) Cable Construction 8 Strand Construction Item Quantity Item Quanitity Strands 6 Wires 5 to 9 External Strands 6 External Wires 4 to 8 Strand Layer 1 Layers Wire 1 Wires 30 to 54 TABLE 3 Diameter Approx Weight Mimun Break Load Diameter Range mm lb/ft kg/m IPS tons 1770 kn EIP tons 1960 kn / / / / / / / / / / / / / IPS = Improved Plow Steel EIPS = Extra Improved Plow Steel For ton/mt Multiply by For kg/mt Multiply by M Max Cables.dd 8 27/09/ :00:23

9 Classification 6X19 AND 6X36 (SC) Cable Construction Strand Construction Item Quantity Item Quanitity Strands 6 Wires 15 to 26 External Strands 6 External Wires 7 to 12 Strand Layer 1 Layers Wire 2 to 3 Wires 90 to 154 CABLE 6X36 ALMA DE ACERO (AA) Typical Examples Wire Ropes Strands 6 X 19 S X 21 F 1-5-5F-10 6 X 26 WS 1-5-(5+5)-10 6 X 19 W 1-6-(6+6) 6 X 25 F 1-6-6F-12 9 Cables.dd 9 27/09/ :00:25

10 10 TABLE 4 Diámeter Approx Weight Mumun Break Load Diamter Range mm lb/ft kg/m IPS tons 1770 kn EIP tons 1960 kn EIP tons 2160 kn M Max / / / / / / / / / / / / / / / / / / / Mimum breakg force for fal-galvanized ropes 10% lower than values listed. Note To convert to kilonewtons (kn), multiply tons by Cables.dd 10 27/09/ :00:25

11 Classification CABLE 6X19 ALMA DE FIBRA (AF) CABLE 6X36 ALMA DE FIBRA (AF) 6X19 AND 6X36 (FC) Typical Examples Wire Ropes Strands 6 X 31 WS 1-6-(6+6)-12 6 X 36 WS 1-7-(7+7)-14 6 X 41 WS 1-8-(8+8)-16 6 X 41 SF F-16 6 X 49 SWS (8+8)-16 6 X 46 WS 1-9-(9+9) Cables.dd 11 27/09/ :00:27

12 Classification TABLE 5 Diámeter Approx Weight Mumun Break Load Diamter Range mm lb/ft kg/m IPS tons 1770 kn EIP tons 1960 kn EIP tons 2160 kn M Max ,3 25, / ,74 3, ,6 31,7 34, / ,26 4, ,4 41,4 45, ,3 52,4 57, / ,1 6,71 7, ,4 64,7 71, ,7 78,3 86, / ,27 9, ,1 93, / ,7 11,8 12, , / ,5 14,9 16, / ,7 18,4 20, / ,8 26,2 28, / ,2 35, , , / ,6 57,9 68, / ,6 71,1 78, / ,7 85, / / / / / / / Mimum breakg force for fal-galvanized ropes 10% lower than values listed. Note To convert to kilonewtons (kn), multiply tons by Cables.dd 12 27/09/ :00:28

13 Classification CABLE 8X19 ALMA DE ACERO (AA) CABLE 8X25 ALMA DE ACERO (AA) 8X19 AND 8X25 (SC) Cable Construction Strand Construction Item Quantity Item Quanitity Strands 8 Wires 15 to 26 External Strands 8 External Wires 7 to 12 Strand Layer 1 Layers Wire 2 to 3 Wires Cable 120 to 232 Typical Examples Wire Ropes Strands 8 X 19 S X 21 F 1-5-5F-10 8 X 26 WS 1-5-(5+5)-10 8 X 19 W 1-6-(6+6) 8 X 25 F 1-6-6F-12 Rope Diameter Nomal (ordered) Maximum (ordered) Approx Circunference Maximum Strand Pitch Lay Approximate Weight 6 X 19 (lb/ft) 8 X 19 (lb/ft) Nomal and Acceptance Breakg Strength 1/4 17/64 3/4 1-11/ ,600 5/16 21/ / ,600 3/8 13/32 1-1/8 2-17/ ,200 7/16 15/32 1-1/8 2-31/ ,000 1/2 17/32 1-1/8 3-3/ ,500 9/16 19/32 1-1/8 3-13/ ,500 5/8 21/ / , lb Nomal Diameter mm () Physical and Mechanical Properties of 8x19 Parallel Layers Table 6 Natural Fiber kg/100m Approx. Mass Fiber Cored Ropes Synthetic Fiber kg/100m M. Break Load correspondg to the nomal tension grade of the wires: 1570 N/Mm 2 Sgle Tensile; 1370/1770 N/Mm 2. Dual Tensile. Both Are Calculated Usg A Sgle Tensile Of 1500 N/mm 2 (kn) 1770 N/mm 2 Simple Tension kn ,7 17, ,2 21,7 28,1 33, ,7 33, , ,2 62, ,6 54,5 54,7 64, ,6 57,3 74,3 87, ,8 86, Cables.dd 13 27/09/ :00:29

14 Classification TABLE 7 Diameter Approx Weight Mumun Break Load Diameter Range mm lb/ft kg/m IPS Tons 1770 kn EIP tons 1960 kn EIP tons 2160 kn M Max / / / / / / / / / / / / / / / / / / / IPS = Improved Plow Steel EIPS = Extra Improved Plow Steel For ton/mt Multiply by For kg/mt Multiply by Wire Ropes Produced accordance with RR-W-410E Standards The break loads for galvanized fish wire ropes, are 10% less than the values listed this table. 14 Cables.dd 14 27/09/ :00:29

15 Classification 18X7 (FC) AND 19X7 (SC) Cable Construction Strand Construction CABLE 18 x7 ALMA DE FIBRA (AF) Item Quantity Item Quantity Strands 17 to 18 Wires 5 to 7 External Strands 10 to 13 External Wires 4 to 6 Strand Layer 2 Layers Wire 1 Wires 85 to 126 Typical Examples Wire Ropes Strands 8 X 19 S X 21 F 1-5-5F-10 8 X 26 WS 1-5-(5+5)-10 8 X 19 W 1-6-(6+6) 8 X 25 F 1-6-6F Cables.dd 15 27/09/ :00:30

16 Classification 18x7 AND 19x7 STEEL CORE (SC) TABLE 8 Diameter Approx Weight Mumun Break Load Diameter Range mm lb/ft kg/m IPS Tons 1770 kn EIP tons 1960 kn EIP tons 2160 kn / / / / / / / / / / / / / IPS = Improved Plow Steel EIPS = Extra Improved Plow Steel For Ton/Met. Multiply by For kg/mt Multiply by Wire Ropes Produced accordance with RR-W-410E Standards The break loads for galvanized fish wire ropes, are 10% less than the values listed this table. M Max 16 Cables.dd 16 27/09/ :00:30

17 8x36 Steel Core (SC) Typical Constructions Wire Ropes Strands 8 X 31 WS-IWRC X 36 WS-IWRC X 41 WS-IWRC CABLE 8X36 ALMA DE ACERO (AA) Tabla 9 Diameter Diameter Tolerance Nomal M. Break Load M. Max. Longitudal Mass IPS EIP EEIP mm mm mm Kg/100m lb/ft kn kn kn kn tons kn tons kn tons (9.5) (3/8) (0.27) 58.4 (6.56) 67.2 (7.55) 73.8 (8.30) (11.1) (7/16) (0.37) 79.1 (8.89) 90.7 (10.2) 99.6 (11.2) (12.7) (1/2) (0.48) 102 (11.5) 118 (13.3) 130 (14.6) (14.3) (9/16) (0.61) 129 (14.5) 149 (16.8) 165 (18.5) (15.9) (5/8) (0.76) 157 (17.7) 183 (20.6) 202 (22.7) (19.1) (3/4) (1.09) 228 (25.6) 262 (29.4) 288 (32.4) (22.2) (7/8) (1.48) 308 (34.6) 354 (39.8) 390 (43.8) 24 ( 1 ) (25.4) (1.93) 399 (44.9) 460 (51.7) 506 (56.9) (28.6) (1-1/8) (2.45) 503 (56.5) 578 (65.0) 636 (71.5) (31.8) (1-1/4) (3.02) 617 (69.4) 711 (79.9) 782 (87.9) (34.9) (1-3/8) (3.66) 743 (83.5) 854 (96.0) 943 (106) (38.1) (1-1/2) (4.35) 880 (98.9) 1010 (114) 1110 (125) (5.11) 1020 (115) 1170 (132) 1300 (146) (5.92) 1180 (133) 1360 (153) 1500 (169) (6.80) 1350 (152) 1550 (174) 1710 (192) (7.73) 1530 (172) 1760 (198) 1930 (217) (8.73) 1710 (192) 1970 (221) 2160 (243) (9.79) (215) 2200 (247) 2420 (272) 17 Cables.dd 17 27/09/ :00:31

18 Security Factors Diameter /mm Construction M. Break Load Kgf TABLE 10 Approx. Weight g/m 1.0 1X7 GIP / X12 GIP / X12 GIP / X19 GIP / X12 GIP / X19 GIP / X32 GIP / X19 GIP Below is the recommended factors comparg the assumed breakg load as compared to the established workg load. Recommended Security Factors WIRE ROPE USES Selection of Non-Rotatg Wire Ropes TIMES Suspension Bridges 3-4 Wire Rope for Cableway Tractor Wire Rope 5-7 Hoistg Wire Rope 5-9 Wire Rope for Passenger Transport 8-12 Wire Rope for vertical applications 5-8 Wire Ropes for oil-field service 8-12 Lift Wire Ropes 8-17 Wches Wire Ropes for wches 4-8 COMMON APPLICATIONS Sector Construction Sector Construction There is no precise rule for determg when to utilize non-rotatg wire ropes the first stance, it is important to consider the experience obtaed with previously wire rope. The variables that help determe this are: MINING PETROLEUM 6 X 7 8 X 19 6 X 19 Liftg 8 X 25 8 X 7 8 X 36 6 X 26 8 X 19 6 X 19 CRANES 8 X 25 6 X 21 8 X 36 6 X 36 6 X 7 6 X 26 FISHING 6 X 19 6 X 26 Lift height. Wire Rope diameter. Pulley diameter. Number of Les. Pulley disposition. Specific torque of the wire rope. It is not recommended to use non-rotatg wire rope when the load is guided. (rotational resistance) Specific Precautions and Installation: Due to its particular design, non-rotatg wire rope presents differences comparison to 6 lace wire rope. The form which they behave, degrade and break, differs respect to all other conventional constructions. 18 Cables.dd 18 27/09/ :00:31

19 Wire Ropes for the Petroleum Industry 1 Reel HANDLING The most common use of these wire ropes is cranes order to lift guided loads. These recommendations apply to all wire ropes general uses. Recommendations for Installation and Use Non-rotatg wire ropes are very delicate and thus require special care durg mountg, use and the selection of matenance equipment. The followg is a list of conditions and precautions that should be observed order to use the non-rotatg wire rope: The diameters of the drum and pulleys used for 18x7 or 19x7 wire ropes should not be less that 40 times the diameter of the wire rope. A diameter equal to 54 times the diameter of the wire rope or greater is recommended. The 18x9 non-rotatg wire rope should be used with pulleys and drums whose diameter should not be less that 25 times the diameter of the wire rope. A diameter 36 or more times greater is recommended. Non-rotatg wire ropes should always be under to tension, thus it is necessary to stall a hook or counterweight order to mata the wire rope taught even when there is no load. Rotatg or spng the load should be avoided because that torsion, distortion will condition will reduce the useful life of the wire rope. The entry angle of the wire rope to a pulley should not be greater than 1.5. If the non-rotatg wire ropes are to be mounted on a hoistg equipment, it is prudent to limit the legs to only two, due to the fact more legs cannot be used. It is recommended that the ties on the end of the non-rotatg wire rope be made of cast Zc or any other metal for low friction. The use of staples, this case, is not a good practice because they allow slippg of the exterior laces (strands) over the core, causg potential surface defects and ternal deviations. 1. Use of Slg or Chas When it is necessary to move the wire rope reel with slgs or chas, wood blocks should be used between the wire rope and the element used (to lift the roll) order to prevent damage to the wires or distortion to the strands the wire rope. 2. Use of Bars When bars are used to move the roll, these should be leveraged agast the edge of the roll, not the wire rope itself 3. Sharp objects The Roll should not roll or fall or hard or sharp objects such a way that can cause damage to the wire rope. 4. Fallg The roll should not be allowed to fall from the truck or platform, this can damage the wire rope or break the roll. 5. Mud, Dirt, Ashes The roll should not come to contact with anythg that can cause surface damage, rust or scratches as dirt, mud or ash. Placg the roll on a pallet, will help to transport as well as protectg the wire rope agast damage 19 Cables.dd 19 27/09/ :00:31

20 2 Handlg Durg Installation 1. Thread Block The blocks should be threaded without wearg agast the slot the pulley 2. Le changes and cut Its good practice durg a le change to suspend the flyg block from the crown, a sgle le. This tends to limit the amount of rubbg over the guards or spacers, to dimish the formation of bends. This practice is also very effective the cuttg procedure. 3. Tension Tension should be mataed from the moment the wire rope is removed from the roll order to restrict its movement. There should be enough tension the wire rope order to assure a good pay off and accommodation. 4. Threadg with a rotatg type clamp It is recommended when a worn wire rope is gog to be replaced by a new one, the use of a clamp to attach the new wire rope to the old one is done. It should not be welded onto the used wire rope order to pull it through the system. 5. Twistg There should be the utmost attention paid order to avoid the twistg of the wire rope, because the formation of a bend, can cause the entire wire rope, or a section. 6. Cleang The use of solvents can cause damage to the wire rope. If the wire rope gets covered dirt, sand or any other contamatg material, it should be cleaned with a brush. 7. Excess of wire rope or dead caps The number of dead caps or excess wire rope should be mataed accordance with the equipment manufacturer s standards. 8. New Wire Rope When possible, the new wire rope should be carefully controlled and monitored, under loads and speeds, for a short period after stallation. This allows the wire rope to settle to the work environment. The EMCOCABLES manufactured SUPER B SHRIMP and SU- PER B FISH galvanized steel wire ropes for fishg have been designed accordg to the heavy work loads fishg ships carry out, as well as the great power developed by these ships today. Our high quality thoroughly meets the demands of the modern fisherman s most important work tool, high resistance, long life wire ropes. The production of our fishg wire ropes is meticulously monitored durg the drawg, galvanization, strandg and closg processes. The most rigid ternational standards are set for the production of our fishg wire ropes. Our quality control is not just limited to approvg fal wires ropes, but to strict oversight durg each of the manufacturg processes. It is to this attetion to detail that we produce fishg cables of unbeatable quality.all of the wires our fishg wire ropes are strong, resistant to tension and heavily galvanized. Together, these factors make our wire ropes resistant to corrosion, abrasion, deformation and yet still mata a great flexibility, an important requirement this type of wire ropes. The dividual diameter of the wires and the geometric design of the strands have been technically and carefully calculated, thus givg the SUPER B fishg wire ropes magnificent physical properties. The polypropylene center is specifically designed for our fishg wire ropes. It is dense, uniform and resistant to seawater. It has the best characteristics of natural fiber core strands but none of the disadvantages. 20 Cables.dd 20 27/09/ :00:32

21 Wire Ropes for Fishg Diagnostic Chart for Faults wire ropes and its causes Fault Symptom Possible Cause By Shippg Deformation of the Wire Rope Bendg and Coils Excessive amount of wire rope on one roll to dispatch Another transported roll hittg the cable Fallg of roll off of truck Roll drum open Rollg the wire rope over the roll a loose manner Mold Deficient Storage Bendg and Coils Improper brakg or elevation of the roll Improper transfer of wire rope from roll to spool Throwg or draggg the cable around a post or sharp pot By Installation Excessive Abrasion Improper functiong of friction caused by the equipment itself or other equipment nearby or front High or Mounted Strands Improper weave, connection or grip Utilization of nails or other objects between the strands Deformation of Wire Rope Improper transfer between roll and drum Overly compressed wire rope Poor rollg on the spool Blows to equipment Bends or Coils Jumpg pulleys Operation over small diameter pulleys Pullg out on the wire rope when its loose and le caused by beg too open or too stretched Liftg the wire rope with a poted object without protection Poor rollg on the roll Broken rolls Corrosion or Wet Poor rollg on the roll lack of lubrication Poor rollg on the roll fluids or corrosive atmosphere By Use Exploded Core Momentary compression force the wire rope which pushes the strands Collidg with fluid a well at high velocity Rollg on small diameter drums Squashg on the roll Excessive Abrasion Improper work. Tight or adjusted pulley mouth. Poorly aligned pulleys. Presence of abrasive material Broken Wires Fatigue by excessive turns over small diameter pulleys or contrary clation Formation of martensite caused by heatg (friction with an object that causes sparks) Slidg over a worn surface Damaged core caused by overloadg Little wire rope mobility cause by stretch-throat pulleys Vibrations caused by defected rollgs Excessive wire rope velocity Broken pulleys or rolls Corrugated pulleys Spaces the Weave Mounted Strands Load suddenly dropped Cut sharp elements, accessories, or unions located the area 21 Cables.dd 21 27/09/ :00:32

22 Wire Ropes for Fishg Problems That Can Arise With Pulleys and their Solutions Pulley Wire Rope Incidents, Causes Observations Too Small Groove Overly Wide Normal Normal The wire rope fatigues rapidly becouse of brunt folds, which caused the outer strands to deteriorate quickly. The strands of the wire rope attack the pulley and draw a spiral prt. The wire rope wears out due to the slidgs and the ertia of the pulley, of a false groove, and fatigues prematurely due to abrasion. Replace the pulley. A convenient pulley should have a relation of 120 to 140 and the borders should have an clation of 40 to 50 Groove Evidence by a Mark Evidence Normal If the previous wire rope had left an impression on the bottom of the groove, this can have a filg effect on the exterior wires of the wire rope. Groove Evidence by a Worn Side Due to contuous excessive rubbg at a great deflection angle or a defective pulley drum alignment. Rectify the pulley or replace it well. Test alignment Deform Groove A flat spot on a pot on the pulley creates a bump the wire rope each pulley revolution. The cumulative effects of this cause a constant fatigue on the exterior strands and engenders a vibration. Replace or rectify Used Pulley New The wire rope elimates old impressions and wears quickly. Bearg or Axis of Broken Pulley Normal Provokes an oscillation and the cable whips around thus reducg its useful life. The wearg of the axis tends to cause a false rotation the pulley and the wire rope fatigue, generally around the connection. Replace the bearg or remount the axis Poorly Rounded or Coated Pulleys Normal The wire rope also whips around and the damaged face can remove itself from use or at least rub together agast the live edge, causg rapid wear. Stiff Pulley Normal The wire rope is worn by filg and produces grooves the pulley. Re-grease the axes of the pulleys and make sure they sp freely Notched Pulley Normal A Notch can destroy thewire rope. Change Wire Rope Undulated Pulley Overly Heavy Pulleys Has a moment of ertia such that its movement doesn t adjust to the wire rope, and acts as a grder agast the exterior wires. Change Wire Rope Normal Pulley Used Too Small The diameter of the groove section results small, if a new wire rope is mounted, it will be too loose the pulley and brush the sides of the pulley, deformg it and eventually destroyg. The wire rope, when isn t tensioned, generally tends to flatten, then it deforms and eventually destroys. 22 Cables.dd 22 27/09/ :00:32

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24 Phone: (57 1) , Fax: (57 1) Ext 2230 Cables.dd 24 27/09/ :00:32