In the construction industry, transport and agriculture – chain slings prove to be reliable in each of these areas. They are an extension of the arms of lifting devices and are used to carry large-size loads. What is worth knowing about them?
What are slings and what are their types?
Chain slings are an additional element of cranes, gantry cranes, cranes and other lifting devices. They consist of a link that connects the slings together and is a link with other devices. The links are attached to the tie rods with hooks at the end of the link. Although they seem inconspicuous, they are very durable. All chain slings should have a nameplate informing about the steel grade, producer, length, WLL and date of production. Chain slings can be divided into two categories:
I category – division based on the number of tendons
There are one, two, three or four leg slings. In slings consisting of several legs, their lengths are the same and there are hooks at the ends. They are used to support transported loads – e.g. containers or large concrete rings. Single leg slings can be terminated with a loop, and this type can help in transporting concrete columns or pipes.
II category – division according to the class of steel
The type of steel the tendons are made of allows them to be divided into several classes – the most popular are class 8 slings. Their phenomenon is that they can be used to carry virtually all materials. However, be careful not to use them in an acidic environment. The hydrogen it contains reacts with the steel, which reduces its strength. The use of such chain slings can be dangerous.
When using chain slings, special precautions should be taken. Do not jerk loads or walk under them. It is also dangerous to swing and rotate objects being carried. Adherence to the rules guarantees the safety of people and things. Manufacturers attach a special table to all chain slings, which informs about their Working Load Limit (WLL). They should be checked each time before starting work, so that you can avoid potential dangers. The WLL is variable and depends on how the tendons are attached and used. The angle of opening of the legs (in the case of multi-leg slings), the type of load and the working environment are also important. When the temperature is high, and the transported object has, for example, sharp ends, the DOR coefficient should be reduced accordingly. Before starting work, carefully check the slings – it guarantees safe work. Every, even the smallest, defect should be reported. The damaged part must be replaced, then the slings can still be used. All equipment working with large dimensions should be inspected. It is no different in the case of chain slings. They should be subject to seasonal inspections (once a year). They take place at the manufacturer’s or in a service center with appropriate authorizations.