Vestil SL-xxx-AA - Manual (Page 23)

23
Maintenance and repair
Chain inspections
Chains used in stackers should be inspected at least once a year or every three months if exposed to severe
contamination or high continuous loading stress.
We recommend that attention be paid to the following points:
1. Unusual noise
2. Surface rust
3. Linkage rust
4. Stiff links
5. Distorted pins
6. Loose link pins
7. Damage
8. Broken link plates
9. Broken pins
10. Contamination
11. Stretching
Even with the optimum amount of lubrication, it is impossible to prevent a chain from stretching.
Wear extends only to that part of the chain which is led over the chain sprocket/guide sprocket. Thus, when
checking for wear, only check the area need be inspected.
According to the regulations currently in force, a chain is deemed to be worn if it has stretched by 3%.
If safety issues are particularly critical or a potential hazard is dependent on a single chain, we consider it necessary
to replace it if it is stretched by even 2%.
Measuring procedure
To measure elongation through wear, that part of the chain which runs over the chain sprocket/guide sprocket must be
positioned in the stretched area. With the aid of a measuring rod, measure a section approximately 1 meter in length.
The number of divisions in the measured area, multiplied by the chain divisions, gives the nominal measurement.
The length extending beyond this measurement represents the wear, which is limited to a maximum of 3% over the
nominal length.
An elongation through wear of 3% is reached if 33 links of the chain in use measure the same length as 34 links of a
new chain.
Chain replacement
If two chains are used as a pair on the affected machine, both should always be changed at the same time.
The installation and removal of chains should be carried out with all the care appropriate to any item of safety
equipment.
Chains may only be repaired by authorized specialist personnel.
We do not recommend the lengthening of safety-type lifting chains, since the inserted chain link will not have been
pre-stretched.
Our product liability will be invalidated if a repaired chain is assembled from sections bearing different silver label
numbers.