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3. Also check chain for stretch using a larger caliper as show below to measure
the outside length of a convenient number of links about 11(pitchs). Measure
the same number of links in a used section of chain and calculate the
percentage increase in length of the worn chain.
4. Chain is to be kept clean and lubricated. Visually check chain every time chain
hoist is used. As oil needs to sit at the bearing surface of each chain link, it is
advised to submerge the chain in oil for 30 min. Take it out and let the chain
hang dripping for 24 hours before putting in the hoist.
Note: In the entertainment industry chain wear in general is only very limited, and
often even impossible to measure after 10 years of normal use. On the other hand it is a
well known fact that the load chains in the entertainment do tend to be misused or even
abused and sometimes badly neglected in corrosion prevention. Severely damaged,
deformed, dented, partly eaten or even broken chain links have been regularly
reported by use in the entertainment sector, and constant attention must be given that
such chains are immediately taken out of service. All this is typically the responsibility
of the customer or user of the chain hoist.
Summary of Contents for DU903
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