Table 1: Hook Throat Dimension
Model No. | Throat Width | Discard Width | |||
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in. | mm | in. | mm | ||
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1.22 | 31 | 1.4 | 35.6 | ||
1.33 | 34 | 1.54 | 39.1 | ||
1.5 | 38 | 1.72 | 43.7 | ||
1.61 | 41 | 1.86 | 47.2 | ||
1.85 | 47 | 2.12 | 54 | ||
2.01 | 51 | 2.31 | 58.6 | ||
2.8 | 71 | 3.21 | 81.6 | ||
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3.54 | 90 | 4.07 | 103.5 | ||
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3.HOOK LATCHES. Check operation of hook latches. Replace if broken or missing.
4.CHAIN. Refer to Dwg. MHP0102 on page 7. Examine each link for bending, cracks in weld areas or shoulders, transverse nicks and gouges, weld splatter, corrosion pits, striation (minute parallel lines) and chain wear, including bearing surfaces between chain links. Replace a chain that fails any of the inspections. Check lubrication and lubricate if necessary. Refer to “Load Chain” in “LUBRICATION” section.
(Dwg. MHP0111)
(Dwg. MHP0102)
•The full extent of chain wear cannot be determined by visual inspection. At any indication of chain wear inspect chain and load sheave in accordance with instructions in “Periodic Inspection.”
•A worn load chain may cause damage to load sheave. Inspect load sheave and replace if damaged or worn.
5.LOAD CHAIN REEVING. Refer to Dwg. MHP0042 on page 9. Make sure welds on standing links are away from load sheave. Reinstall chain if necessary. Make sure chain is not capsized, twisted or kinked. Adjust as required.
Periodic Inspection
According to ASME B30.16, frequency of periodic inspection depends on the severity of usage:
NORMAL | HEAVY | SEVERE |
yearly | semiannually | quarterly |
Disassembly may be required for HEAVY or SEVERE usage. Keep accumulative records of periodic inspections to provide a basis for continuing evaluation. Inspect all items in “Frequent Inspection.” Also inspect the following:
1.FASTENERS. Check rivets, capscrews, nuts, cotter pins and other fasteners on hooks, hoist body and chain bucket, if used. Replace if missing and tighten or secure if loose.
2.ALL COMPONENTS. Inspect for wear, damage, distortion, deformation and cleanliness. If external evidence indicates the need, disassemble. Check gears, shafts, bearings, sheaves, chain guides, springs and covers. Replace worn or damaged parts. Clean, lubricate and reassemble.
3.HOOKS. Inspect hooks for cracks. Use magnetic particle or dye penetrant to check for cracks. Inspect hook retaining parts. Tighten, repair or replace if necessary. Refer to the latest edition of ASME B30.10 (Hooks) for additional hook inspection information.
4.CHAIN SHEAVES. Check for excessive wear or damage. Replace if necessary.
5.BRAKES. Ensure proper operation. Brake must hold hoist rated capacity. If load test indicates the need, disassemble. Brake discs must be free of excess oil, any grease, unglazed, uniform in thickness and at least 5/64 in. (2 mm) thick. Check all other brake surfaces for wear, deformation or foreign deposits. Inspect pawl brake. Teeth of ratchet gear should be undamaged, and should stop gear rotation in the counterclockwise direction. Check pawl spring for damage. Clean and replace components as necessary.
6.SUPPORTING STRUCTURE. If a permanent structure is used, inspect for continued ability to support load.
7.LABELS AND TAGS. Check for presence and legibility. Replace if necessary.
8.END ANCHOR. Ensure end anchor on chain hoist is engaged and unbent. Repair if damaged, replace if missing. Refer to “Attaching End of Load Chain” in “MAINTENANCE” section.
9.LOAD CHAIN. Measure chain for stretching by measuring across five link sections all along chain. Refer to Dwg. MHP0041on page 8 and Table 2. When any five links in the working length reach or exceed discard length shown in Table 2, replace entire chain. Always use a genuine
MHD56012 - Edition 8 | 7 |