1. Legal basis
The technical requirements and instructions regarding the manufacture of roundslings and webbing slings are specified for the whole of Europe in EN 1492-1 and 1492-2.
The standards are called EN in each country, prefixed by the national standards institute, e.g. DIN EN in Germany and BS EN in the UK, followed by the same number in each country. As a sign of conformity according to the Machinery Directive 98/37/EC, textile slings which comply with the
European standard bear the CE mark. In addition, the BG guidelines BGR 500 also apply.
2. Working load limit and mode factor
The weight of the load and the type of anchor (mode of assembly or use) determine the working load limit of the sling. The most frequent types of anchors used for webbing slings and
round slings are given in the following table.
The working load limit of a sling changes depending on the type of anchor. The change in working load limit is given by the mode factor. The rated capacity (Safe working load) of a sling is given by the "single direct" mode. The mode factor for the other mode of assembly or use (types of anchor) are given in the table above.
Important: The included angle may not exceed 60°. Beyond this angle the forces are uncontrollable
3. Handling and use
The rated capacity of webbing slings and round slings is coded by a colour defined in the European standard. The user therefore has additional safety when assigning the working load limit (see Working load limit table). All rated capacities from 10,000 kg are orange, all intermediate sizes must be identified by a unique different colour (olive at SpanSet).
Webbing slings and roundslings made from polyester can be used within a temperature range of -40 to +100° C. They can also be used in chemicals following prior checking and release by the manufacturer. If anchoring with textile webbing and roundslings, the surface and edges of the load must be taken into account, because sharp edges are dangerous and can damage the sling.
A sharp edge always exists if the edge radius "r" is smaller than the thickness "d" of the sling material. If the load is sharp-edged or if the load has a rough surface, the textile sling must be equipped with suitable abrasion protection, protective hoses or fixed coatings.
Caution: No abrasion protection replaces firm cut-proof edge protection against sharp-edged loads! When using roundslings and webbing the user benefits from the low self-weight of the sling and the ability to anchor loads using methods which protect their materials.
Practical tips: Roundslings can be joined using a "Joker" hook to extend their length Roundslings must never be knotted together or roped together, as the working load limit is reduced by an uncontrollable amount.
4. Testing and maintenance
Chemical fibre webbing and roundslings must be tested at least once a year by a competent person. Shorter testing intervals may be required, depending on the use conditions. The most frequent defects are cuts in the load-bearing fabric, fire damage due to flying sparks, mechanical damage to the load-bearing seams/stitching and the roundsling hose. Repair work may only be carried out by the manufacturer or a person assigned by them.
We would be pleased to teach you how to handle slings correctly in one of our seminars on lifting and lashing.