Round Slings, sometimes referred to as Endless Slings, are made of continuously wound high-performance polyester yarn encased in a tubular single-ply or double-ply Polyester cover. Often identified by colour, the cover usually gives a visual indication of its rated capacity while shielding the internal yarn from external threats.
Round slings are versatile, lightweight, and offer superior load protection for sensitive materials and finished parts.
Advantages of Using Round Slings
Disadvantages of Using Round Slings
Round Sling Inspection: Failure Criteria
When inspecting a Round Sling, it is important to be able to identify common signs of damage and misuse. Inspecting your sling before every lift helps to ensure the longevity of the sling, the safety of those around the job site, and the protection of the load being lifted. Key warning signs that your sling needs to be pulled from service include:
Abrasion damage occurs when a round sling encounters a rough surface with enough force to wear down the protective sleeve, potentially exposing the inner fibres.
Acid Burns damage the outer jacket of both Nylon and Polyester slings; if a strong enough acid is involved it can expose the inner fibres and damage them.
Burn Damage occurs when a sling is exposed to temperatures exceeding 194°F. Because they are made of synthetic materials, exposure to heat at this level will cause them to melt.
Tears and Cuts occur when a sling is not properly padded for a load, causing excessive tension to be placed on a small portion of the sling, potentially ripping the outer sleeve and internal yarn.
Knotting causes unequal distribution of tensile force around the knotted area reducing the Working Load Limit (WLL). The same concept is applied when calculating the rated capacity of a sling in a choker hitch. Because there is an increase in tensile force at the point of the choke (or the “knot”), the slings WLL is reduced to account for the extra strain. It is important to note that you should never tie a knot in a sling to adjust its length.
Illegible Tags indicate that some or all details on the sling tag can no longer be identified properly. Equipment being used for overhead lifting should always be tagged with specs to ensure the right sling is being used based on the lift requirements. There should never be any guessing involved when selecting a sling.
Weld Splatter is harmful to Round Slings because the jacket and fibres are not resistant to heat. The presence of weld splatter indicates that the structural integrity of the protective sleeve, and possibly the internal fibres, could be compromised.
Pulled Yarn indicates that the sling may have been exposed to a shock load, damaging the internal fibres.
Exposed Core is easy to identify with a visual inspection. If you can see the core (yarns) of the sling, it must be removed from service.
The use of latches on hooks is a topic that is constantly up for debate in the lifting and rigging industries. While some people argue that hook latches are always required and should always be utilized, others argue that latches are not required.
Unfortunately, there are limited explanations or interpretations of when a latch on a hook must be utilized. With no clear industry-wide rules on whether a hook latch is required on a crane hook or a sling hook, the decision is ultimately left up to the owner or end-user. When deciding on whether to use a latch or not, careful consideration must be given to the specific lifting application.
Client requirements and Safety Best Practices typically will be the driving factor of using latches with hooks. Common sense is the prevailing factor. In short, you never want to loose an elevated load due to the cable or belt jumping out of the hook eye (disengagement). Latches help prevent this from occurring.
When using a hook & latch on pipeline ROW, the latch shall be functional and expected when lifting pipe for welding, moving pipe or equipment, etc. However when lowering-in pipe into the trench, the latch is typically “tapped-back”. This is to prevent personnel from getting anywhere near the open ditch and pipe during lowered-in. Often a rope is tied to the hook also to release belt and hook from pipe after lowering into the ditch.
The latch on the hook is to prevent the load from jumping off the hook. For those who have been in the field for a while, we have seen that muddy belts holding pipe which might jump the belt out of the eye of the hook when traveling pipe down ROW or other scenarios. Cold or frozen belts can also cause similar reactions.
Use the latch as the default method. And always inspect and take good care of the belts and straps.