haklift NKVE06202LVP Chain Sling Toolbox 2 Legs User Manual
- June 9, 2024
- haklift
Table of Contents
haklift NKVE06202LVP Chain Sling Toolbox 2 Legs
Use of chain slings
Chain sling selection
General
Haklift Grade 100 chain slings are assembled of components manufactured
according to relevant parts of European standards EN 818 and EN 1677 and
comply with European Machinery directive 2006/42/EC. Before taking the chain
sling into use the user must read and understand this operating manual
provided with the delivery of Haklift Grade 100 chain slings. The main
dimensions and working load limits for the chain slings are presented in Table
- Each chain sling is equipped with an identification tag that presents the main characteristics of the particular chain sling.
| | 1-leg 2-leg
3- and 4-leg
---|---|---
Chain
| — -6-0°– -60
0–kg–
6| 1400| 1960| 1400| 2940| 2100
8| 2500| 3500| 2500| 5250| 3750
10| 4000| 5600| 4000| 8000| 5700
13| 6500| 9100| 6500| 13700| 9800
16| 10000| 14000| 10000| 21000| 15000
20| 16000| 22400| 16000| 33600| 24000
22| 19000| 26600| 19000| 39900| 28500
Coefficient used in calculating permitted workloads
1 1,4 1 2,1 1,5
For a tightening lift, the table values are multiplied by 0,8
Use in adverse environments
High and low-temperature conditions
Care should be taken to take into account the maximum temperature, which can
be reached by the chain sling in service. This is difficult in practice but
underestimation of the temperature involved should be avoided. The maximum
temperature for Grade 100 chain slings is 205 °C. If chain slings reach
temperatures in excess of the maximum permissible temperature given, they
should be withdrawn from service and referred to the manufacturer.
Chain slings of Grade 100 will not be adversely affected by temperatures down to -29 °C and no reduction from the working load limit is, therefore, necessary on this account. Where chain slings are to be used at temperatures below -29 °C, the manufacturer should be consulted.
Acidic conditions
Chain slings of Grade 100
Chain slings of Grade 100 should not be used either immersed in acid solutions
or exposed to acid fumes. Attention is drawn to the fact that certain
production processes involve acidic solutions and fumes and in these
circumstances, the manufacturer’s advice should be sought. For the same
reasons, chain slings should not be galvanized or subjected to any plating
processes without the approval of the manufacturer.
-
Conditions in which the chain sling is likely to be subjected to attack (chemical, abrasive, etc.)
The manufacturer of the chain sling should be consulted, particularly if the chain sling is to be exposed to highly concentrated chemicals combined with high temperatures. -
Use in exceptionally hazardous conditions
The rating of lifting accessories in European Standards assumes the absence of exceptionally hazardous conditions. Exceptionally hazardous conditions include offshore activities, the lifting of persons, and the lifting of potentially dangerous loads such as molten metals, corrosive materials, or fissile materials. In such cases, the degree of hazard should be assessed by a competent person, and the working load limit adjusted accordingly. -
Chain sling verification before first use and in service
Before first use
Before first use of the chain sling, it should be ensured that the:
- the chain sling is precise as ordered;
- the manufacturer’s certificate is to hand;
- the identification and working load limit marking on the chain sling correspond to the information on the certificate;
- full details of the chain sling are recorded.
Before each use
Before each use, the chain sling should be inspected for obvious damage or
deterioration (see 2.1.). If faults are found during this inspection, the
procedure given in 2.1. should be followed.
Handling the load
Preparation
Attention should be given to any specific instructions provided for the
handling of the load. Before starting the lift, it should be ensured that the
load is free to move and is not bolted down or otherwise obstructed.
Mass of the load
It is essential that the mass of the load to be lifted is known. If the mass
is not marked the information should be obtained from the consignment notes,
manuals, plans etc. If such information is not available the mass should be
assessed by calculation.
Centre of gravity
The position of the center of gravity of the load should be established in
relation to the possible points of attachment of the chain sling. To lift the
load without it tilting or toppling the following conditions should be met:
- For single-leg and endless chain slings, the attachment point should be vertically above the center of gravity.
- For two-leg chain slings, the attachment points should be on either side of and above the center of gravity.
- For three and four-leg chain slings the attachment points should be distributed in a plan around the center of gravity. It is preferable that the distribution should be equal (but see 1.3.5) and that the attachment points should be above the center of gravity.
When using two-, three- and four-leg chain slings the attachment points and chain sling configuration should be selected to achieve angles between the chain sling legs and the vertical within the range marked on the chain sling. Preferably all angles to the vertical (angle r.. in figure A.1) should be equal (but see 1.3.5). Angles to the vertical of less than 15° should be avoided if possible as they present a significantly greater risk of load imbalance.
All multi-leg chain slings exert a horizontal component of force (see figure A.1) which increases as the angle between the chain sling legs is increased. Where hooks or other fittings are threaded on a loop of chain, e.g. case chain slings and drum chain slings, the horizontal component of force is much greater and consequently, the angle of such legs should not exceed 30° to the vertical. Care should always be taken to ensure that the load to be moved is able to resist the horizontal component of force without being damaged.
The hook to which the chain sling is attached should be directly above the center of gravity.
Method of connection
A chain sling is usually attached to the load and the lifting machine by means of terminal fittings such as hooks and links. Chains should be without twists or knots. The lifting point should be seated well down in a hook, never on the point or wedged in the opening; the hook should be free to incline in any direction so as to avoid bending. For the same reason, the master link should be free to incline in any direction on the hook to which it is fitted.
The chain may be passed under or through the load to form a choke hitch (see figure A.2) or basket hitch (see figure A.3). Where it is necessary, due to the danger of the load tilting, to use more than one chain sling leg in a basket hitch, this should preferably be done in conjunction with a lifting beam. When a chain sling is used in a choke hitch, the chain should be allowed to assume its natural angle and should not be hammered down.
Chain sling legs may be attached to the load in several ways:
Straight leg
In this case, lower terminals are connected directly to the attachment points.
The selection of hooks and attachment points should be such that the load is
carried in the seat of the hook and tip loading of the hook is avoided. In the
case of multi-leg chain slings hooks, tips should point outwards unless the
hooks are specifically designed to be used otherwise.
- Loading of leg
- The horizontal component of force
- Load 10 t
Figure A.1. Variation of chain sling leg loading with leg angle for a load
of 10 t.
The hatched area indicates angles greater than 60° to the vertical at which
chain slings should never be used.
Figure A.2. Choke hitches.
Figure A.3. Basket
hitches.
Choke hitch
In this case, chain sling legs are passed through or under the load and the
lower terminal back is hooked or reeved onto the chain (see figure A.2). This
method can, therefore, be used where no suitable attachment points are
available and has the additional advantage that the chain sling legs tend to
bind the load together. Where a choke hitch is employed the working load limit
(WLL) of the chain sling should be no more than 80 % of that marked.
Basket hitch
The chain sling is passed through or under the load as in b) but in this case
the lower terminals are connected directly to the master link or to the hook
of the lifting machine. Generally, this method requires two or more chain
sling legs and should not be used for lifting loads that are not held
together. Where the load geometry permits, a single-leg chain sling can be
used provided that the chain sling passes through the load directly above the
center of gravity of the load. Examples of basket hitches are given in figure
A.3.
Wrap and choke or wrap and basket hitch
These methods are adaptations of b) and c), designed to provide extra security
of loose bundles and involve taking an extra loop of chain completely around
the load. If two or more chain sling legs are used in a choke hitch or a wrap
and choke hitch care should be taken:
- if it is important to avoid imparting torque to the load, to align the chokes; or
- if it is important to avoid the load rolling or moving laterally when first lifted, to ensure that (at least) one leg passes either side of the load.
Packing may be required where a chain comes into contact with a load in order
to protect either the chain or the load or both, since sharp corners of hard
material may bend or damage the chain links or, conversely, the chain may
damage the load because of high contact pressure. Packings, such as wooden
blocks, or corner protectors may be used to prevent such damage.
In order to prevent dangerous swaying of the load and to position it for
loading, a tagline is recommended. When loads are accelerated or decelerated
suddenly, high dynamic forces occur which increase the stresses in the chain.
Such situations, which should be avoided, arise from snatch or shock loading
e.g. from not taking up the slack chain before starting to lift or by the
impact of arresting falling loads.
Symmetry of loading
WLL values have been determined on the basis that the loading of the chain
sling is symmetrical. This means that when the load is lifted the chain sling
legs are symmetrically disposed of in plan and subtend the same angles to the
vertical ( see figure A.4 ).
In the case of three-leg chain slings, if the legs are not symmetrically disposed of in plan the greatest tension will be in the leg where the sum of the plan angles to the adjacent legs is greatest. The same effect will occur in 4 leg chain slings except that the rigidity of the load should also be taken into account, with a rigid load the majority of the mass may be taken by only three or even two legs with the remaining leg or legs serving only to balance the load (see figure A.5).
In the case of two-, three- and four-leg chain slings, if the legs subtend different angles to the vertical the greatest tension will be in the leg with the smallest angle to the vertical. In the extreme case, if one leg is vertical, it will carry all the load (see figure A.5). If there is both a lack of symmetry in the plan and unequal angles to the vertical the two effects will combine and may either be cumulative or tend to negate each other (see figure A.5).
The loading can be assumed to be symmetric if all of the following conditions are satisfied:
- the load is less than 80 % of marked WLL; and
- chain sling leg angles to the vertical are all not less than 15°; and
- chain sling leg angles to the vertical are all within 15° of each other; and
- in the case of three- and four-leg chain slings, the plan angles are within 15° of each other.
If all of the above parameters are not satisfied then the loading should be
considered as asymmetric and the lift referred to a competent person to
establish the safety rating for the chain sling. Alternatively, in the case of
asymmetric loading, the chain sling should be rated at half the marked WLL
(see figure A.5). If the load tends to tilt, it should be lowered and the
attachments changed. This can be accomplished by repositioning the attachment
points or by using compatible shortening devices in one or more of the legs.
Such shortening devices should be used in accordance with the manufacturer’s
instructions.
Figure A.4. Multi-leg chain slings: Load distribution.
- Centre of gravity
- High tension in this leg
- Load P
Figure A.5. Asymmetric loading.
Safety of lift
Hands and other parts of the body should be kept away from the chain to
prevent injury as the slack is taken up. When ready to lift, the slack should
be taken up until the chain is taut. The load should be raised slightly and a
check made that it is secure and assumes the position intended. This is
especially important with baskets or other loose hitches where friction
retains the load. Lifting personnel must always make sure that no one is near
or under the lifted load. Reference should also be made to ISO 12480-1 for
planning and management of the lifting operation and the adoption of safe
systems of working.
Multileg chain slings with less than the full number of legs in use As a general principle, chain slings should be used only for the purpose for which they have been designed. In practice, however, occasions may arise when a lift needs to be made using a smaller number of legs than the number of legs in the chain sling. In such cases the WLL should be reduced from that marked on the chain sling by applying the relevant factor given in Table 2. Legs that are not in use should be hooked back to reduce the risk of such legs swinging freely, or snagging when the load is moved.
Table 2. Working load limit (WLL) factors.
| Type of chain sling | Number of leqs used | Factorv to apply to marked WLL |
|---|---|---|
| 2-leg | 1 | 1/2 |
| 3- and 4-leg | 2 | 2/3 |
| 3- and 4-leg | 1 | 1/3 |
Working load limit (WLL)
Taking into consideration items 1.3.1 to 1.3.7 and the cumulative effects of
de-rating, the method of chain slinging should be decided and a suitable chain
sling or chain slings selected, having a WLL equal to or greater than the
mass to be lifted.
Landing the load
The landing site should be prepared. it should be ensured that the ground or
floor is of adequate strength to take the weight taking into account of any
voids, ducts, pipes etc. which may be damaged or collapsed. it should also be
ensured that there is adequate access to the site and that it is clear of any
unnecessary obstacles and people. it may be necessary to provide timber
bearers or similar material to avoid trapping the chain sling or to protect
the floor or load or to ensure the stability of the load when landed.
The load should be landed carefully. Care should be taken to avoid trapping the chain sling beneath the load as this may damage it. Before allowing the chain to become slack, the load should be checked to ensure that it is properly supported and stable. This is especially important when several loose objects are in the basket hitch and choke hitch. When the load is safely landed the chain sling should be removed by hand. The chain sling should not be dragged out with the lifting machine since it may thereby be damaged or it may snag and cause the load to topple over. The load should not be rolled off the chain sling as this may damage the chain sling.
Storage of chain slings
When not in use chain slings should normally be kept on a properly designed
rack. They should not be left lying on the ground where they may be damaged.
If the chain slings are to be left suspended from a crane hook, the chain
sling hooks should be engaged in an upper link to reduce the risk of chain
sling legs swinging freely or snagging. If it is likely that chain slings will
be out of use for some time they should be cleaned, dried and protected from
corrosion, e.g. lightly oiled.
Maintenance
Inspection
The chain sling should be withdrawn from service and referred to a competent
person for a thorough examination if any of the following are observed:
- The chain sling markings are illegible, i.e. information on the chain sling identification and/or the working load limit.
- Distortion of the upper or lower terminals.
- Chain stretch.
- Wear:
Wear by contact with other objects usually occurs on the outside of the straight portions of the links where it is easily seen and measured. Wear between adjoining links is hidden. The chain should be slack and adjoining links rotated to expose the inner end of each link. Inter-link wear, as measured by taking the diameter indicated (d1) and one at right angles, (d2) may be tolerated until the mean of these diameters has been reduced to 90 % of the nominal diameter (dn) (see figure A.6) provided.
- Cuts, nicks, gouges, cracks, excessive corrosion, heat discoloration, bent or distorted links or any other defects.
- Signs of “opening out” of hooks. The increase in throat opening should not exceed 10 % of the nominal value or be such as to allow the safety latch, if fitted, to become disengaged.
Figure A.G. Inter-link wears on links.
Thorough examination
A thorough examination should be carried out by a competent person at
intervals not exceeding twelve months. This interval should be less where
deemed necessary in the light of service conditions. Records of such
examinations should be maintained.
Chains slings should be thoroughly cleaned so as to be free from oil, dirt and rust prior to examination. Any cleaning method which does not damage the parent metal is acceptable. Methods to avoid are those using acids, overheating, removal of metal or movement of metal which may cover cracks or surface defects. Adequate lighting should be provided and the chain sling should be examined throughout its length to detect any evidence of wear, distortion or external damage.
Repair
Any replacement component or part of the chain sling should be in accordance
with the appropriate European Standard for that component or part. With Grade
100 chain slings, if any chain link within the leg of a chain sling is
required to be replaced then the whole of the chain within that leg should be
renewed. The repair of the chain in welded chain slings should only be carried
out by the manufacturer using a resistance butt or flash butt welding process.
Components that are cracked, visibly distorted or twisted severely corroded or have deposits that cannot be removed should be discarded and replaced. In the case of chain slings on which repair work has involved welding, each repaired chain sling should be proof tested following heat treatment using a force equivalent to twice the working load limit and thoroughly examined before it is returned to use. However, where repair is carried out by inserting a mechanically assembled component, proof-testing is not required providing that the component has already been tested by the manufacturer in accordance with the relevant European standard.
The accuracy of the tensile test equipment should be of class 2 as given in EN 10002-2. All repairs and testing must be conducted by a qualified person. It is not allowed to modify the product in any way.
Haklift Oy
Asessorinkatu 3-7 20780 Kaarina, Finland Tel. +358 2 511 5511
sales@haklift.com
www.haklift.com.
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