Service Data

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5.6 Inspection the hook block

[NOTICE]

The hook block is an important safety part. Follow the procedure below to inspect it and be sure to use it only under safe conditions.

If any problems are found during inspections, repair or replace the part immediately. A change inspection must be performed when parts are replaced.

1. The sheave groove must be smooth to avoid damaging the wire rope. Use a grinder to smooth and correct any sharp corners.

2. Check whether or not the sheaves turn lightly. If a sheave turns heavily, the wire rope will slide against the sheave, and the rope may be damaged. If a sheave turns heavily, inspect the sheave bearings, and lubricate or replace them if necessary.

3. Check that the sheave split pins and installation bolts are securely installed.

4. Check that the hook nuts are securely installed. If necessary, tighten them further or take steps to prevent their rotation.

5. Replace any worn or damaged hook nuts immediately.

6. Check that the wire rope latch functions correctly. If necessary, replace the spring.

Determination of limit minor diameter rope of nominal diameter less than 25 mm are used)

Limit minor dia.

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7. Perform a magnetic flaw detection test at least once a year to check for cracks or other flaws in the hook. Replace the hook immediately if any cracks are found.

8. As shown in the figure, punch marks are stamped on each hook. Replace the hook when the deformation of the dimension (a) between these marks has increased by 5%.

9. The wear limit of the hook (b) is 3% of the whole thickness (c). Hook service limits (1 mm = 3.93701 × 10-2 in)