pewag Winner pro G12 Originalbetriebsanleitung Seite 26

Figure 10: Choke hitch
in the same direction
E
Figure 12: Reverse choke hitch
Temperature: Lifting chains can be used partly above the specified application temperature with limitations.
Higher temperatures mean that the load capacity is reduced. The permissible temperatures along with the
associated reduction factors can be found in the table with the demanding conditions. The permissible load
capacity with higher temperatures comes about by multiplying the load capacity on the tag with the corresponding
reduction factor from the table. However, it is harder to estimate the exact maximum temperature the chain can
withhold in praxis – one should always assume a higher temperature for safety purposes.
The reduction of load capacity with higher temperatures should always be applied until the chain and/or the parts
have cooled down to room temperature.
Lifting chains should not be used outside of the specified temperature range; if the chains are used by accident
outside of the temperature range, they must be taken out of operation.
Impact/shocks: If loads are accelerated or slowed down abruptly, high dynamic forces are applied which increase
the tension on the lifting chain. Operating conditions which are to be avoided occur due to sudden or impulsive
loading. Impacts are divided into three categories which are listed in the accompanying table along with the
reduction factor. The permissible load capacity of the chain sling in this case arises from multiplying the load
capacity of the tag with the corresponding reduction factor.
Vibrations: pewag lifting chains and accessories are designed for 20.000 load cycles. Nevertheless there is always
a danger that the chain or the components will become damaged from the high dynamic stress involved. According
to the trade association Metall Nord Süd, these stresses on the working load can be mitigated by increasing the
nominal thickness.
Asymmetry: If the chain strands are not ordered symmetrically and do not show the same angle of inclination – as
described under the subtitle "Angle of Inclination" – the load is asymmetrical and the weight will not be equally
distributed on all chain strands. In this case, a professional should be called and the following should be observed:
Asymmetrical arrangement of the chain strands and unbalanced angles of inclination can overlap or offset each
other. If the angle of inclination differs amongst each strand when using two, three or four strand lifting chains, then
the most stress can be found on the single strand with the smallest angle of inclination (see figures 14-16). The load
capacity according to the tag must be accordingly reduced by the WLL of one or more chain strands so that no
single strand is overloaded. In the extreme instance, a vertically suspended single strand will carry the complete load.
26
Figure 11: Wrap and choke hitch
in the same direction
Figure 13: Reverse wrap
and choke hitch