Storage and maintenance

Storage
To avoid damage, chain slings must be stored hanging on suitable brackets and not left lying on the ground. If chain slings are to remain unused for long periods of time, it is advisable to clean and lightly oil them to protect them against corrosion. Fabric slings must be stored in a clean, dry place and must not be exposed to direct sunlight as ultraviolet rays could damage them.

Periodic inspections
Regularly inspect the chains before each use, in a clean, well-lit place, to make sure they are not defective or damaged. Keep a record of all periodic inspections, which must be carried out by a skilled person. The maximum interval between inspections is one year, but frequency may vary according to legislation in force in the country in which the chains are used. In the case of continuous or particularly heavy use the frequency of inspections must be increased accordingly.

Maintenance and repair
Repair or maintenance of slings must be carried out by expert and skilled personnel. Components which show signs of distortion, cracks, breaks, serious corrosion or any other damage, or on which the maximum permissible wear limit has been reached, must be replaced with genuine spare parts (Fig. 9 -10).

When sling components have to be replaced, always use new pins and spring pins. If any of the chain links are damaged, always replace the entire leg of the sling. Minor defects such as small nicks or gouges should be removed with extreme care, using a file. The surface must never show signs of an abrupt variation in the cross sectional area of the material. Always check that removal of minor defects has not reduced the nominal diameter of the section by more than 10%. Never carry out any welding operations on the chain or its accessories. In normal use, fabric slings are subjected to continual rubbing which, over time, causes them to wear and may reduce the strength of the sling. Damage due to heat or severe friction can be recognized by the shiny appearance of the fibres or, in extreme cases, by fusion of these fibres. Certain chemicals can cause local softening of the fabric or sheathing, resulting in the formation of superficial cracks or tears. In conclusion, if any defects or damage are found which could affect safe use of the slings, they must be taken out of service and thoroughly inspected by skilled personnel.

Conditions requiring immediate withdrawal of the sling from service
If any one of the following conditions occurs, the sling must immediately be taken out of service:

• identification plate or label illegible or missing;
• one or more components showing distortion, cracks, breaks or any sign of damage (Fig. 9 - 10);
• the opening of a hook mouth differs by more than 10% from the nominal size indicated in the catalogue (Fig. 11 );
• the sling has been used for a load exceeding the permissible WLL;
• the sling has been exposed to temperatures higher or lower than those permissible;
• the chain links no longer move freely against each other;
• the chain is worn by more than 10% of the nominal diameter (Table 5).