Q1. What is a
synthetic sling?
- A sling connects the crane hook
to the load and is an import rigging tool. Slings can be made of
steel wire rope, chains or synthetic man made fibers like
polyester, nylon, K-spec or Kevlar. A synthetic sling is a sling
made up of synthetic yarn like nylon, polyester or K-spec.
Q2.
How are synthetic slings better than conventional wire ropes and
chains?
- Synthetic slings made of man
made high tenacity fibers have many advantages and conventional
wire ropes and chains. Some of these are :
- Very light and therefore easy to
rig and handle.
- Do not damage sensitive or
delicate surfaces, therefore lower industrial wastage.
- Are colour coded for ease of
identification, therefore less chances of misuse.
- Improve productivity and
employee morale, therefore better labour relationships.
- Do not rust or corrode and
therefore do not weaken with age.
- Easy visual inspection, saving
frequent inspection and proof load costs.
- Save storage costs as they are
flexible and light and therefore easy to store.
- Grips load tightly along the
contours of the load.
- Eliminates need for consumables
like grease and hand gloves, therefore lower recurring costs.
- Lower injuries to employees and
riggers, therefore lower compensation claims.
- Reduces machine downtime, in
industries where dies or work rolls will have to be changed using
slings.
Q3.
What are the disadvantages of using synthetic slings?
A. The
disadvantages if used improperly are :
- Can be easily cut or damaged if
used unprotected over sharp edges.
- Can not be used in temperatures
exceeding 80 degree Celsius.
- Higher initial cost compared to
conventional slings but pay back period is very quick.
Q4.
Can these disadvantages be overcome?
- Yes, if the load to be lifted
has sharp edge, we recommend the use of Anticutting wear pads.
- If rough/abrasive surface is
expected, use anti-abrasive pads.
- If temperature of the load being
lifted are likely to exceed 80 C, ask for special
nomex covering.
- Whilst comparing cost of
synthetic slings to steel wire ropes/chains, do a thorough Cost
Benefit Analysis. A Cost Benefit Analysis done by many corporates
who use the conventional method of lifting suggests that the
higher the value of the material being handled, the quicker the
pay back period. A complete Cost Benefit Analysis would quantify
the savings in terms of :
- Savings to damage to material
being handled (in value).
- Increase in productivity (due
to lower time in rigging and handling the job and/OR lower
machine downtime).
- Reduction in injuries and
employee compensation claims.
- Savings in consumables costs
like grease and hand gloves.
- Savings in storage costs
(synthetic slings require much lesser space to store compared
to steel wire ropes and chains). Savings
in regular testing and inspection costs (steel wire
ropes/chains require regular testing and certification is
their strength reduces with age).
- Savings due to lower inventory
of slings (typically when a factory switches to synthetic
slings it reduces the total number of slings required for
different jobs).
Q5.
What are TWIN PATH slings?
- TWIN
PATH slings are basically two slings in one. There are TWO
INDEPENDENT LOAD CARRYING PATHS offering 100% back up protection
in case of misuse or sudden failure due to mishandling. In such
a scenario, even if one path is cut, the other path still
controls the load, ensuring the highest degree of safety.
Q6.
What are the other salient features of TWIN PATH slings?
- TWIN
PATH slings, besides being the only slings in the world to offer
100% back up protection, also have the following unique features
:
- "Tell-Tails"
: These unique overload indicators which warn the safety or
inspecting officer if the sling has been subjected to overload
at any time during the life of the sling.
- Fiber
Optic inspection : This unique feature warns if the fibers have
been crushed or used in a chemically harmful environment.
- Reparability
: These are the only slings in the world which are repairable.
If the outer cover is damaged or torn, the sling does not have
to be discarded or put out of use, simply repair it by returning
it to us.
- Double
Cover : A double cover prolongs the life of the sling by
protecting the inner core yarns.
Q7.
What is the life of a TWIN PATH sling?
- The
life of a TWIN PATH sling is as long as it is not cut or
damaged. This can last
upto even ten years or more if used properly and carefully.
Q8.
If the outer cover of the sling is torn, do I take the sling out of
service.
- Yes,
however please call us and if after inspection and testing we
find that the inner core yarns are not damaged, we will repair
the sling at a very nominal cost.
Q9.
I am unsure if the sling will lift heavy loads. I am afraid it
might cause accidents
on my shop floor.
- Accidents
in the shop floor are normally caused by negligence rather than
faulty equipment. A TWIN PATH sling is the SAFEST piece of
rigging equipment money can buy. This is because it is the only
sling in the world to have a 100% back up, redundant protection,
which every safety officer wants. Besides as the inspection is
visual - "If it looks alright, it is alright".
Q10.
Which is the best synthetic fiber, nylon, polyester or K-spec.
- The
K-spec fiber is the "best" fiber in terms of high
strength and very low stretch equivalent to steel. However it is
also an expensive fiber. But for slings of capacity over 30
Metric Tones safe working load, there is no alternative to
K-spec fiber.
However, for slings of capacity from 1 MT to 30 MT, polyester
and nylon are normally used. Polyester is a preferred fiber
because it stretches much less than nylon
and has much better resistance to chemicals and sunlight.
Q11. What is the difference between a webbing sling and round sling?
- A
webbing sling has two eyes at two ends and has a flat
construction. It is a very popular design, but has one major
disadvantage. The fibers which provide the strength to lift the
load are also the ones which come in contact with the load.
Therefore, in case of damage to the yarns, the sling has to be
taken out of service. A
round sling is an endless hank of yarn wound without any break
and is a far better designed sling. The inner core yarn (which
provides the strength to lift the load) is protected by the
outer casing, which comes into contact with the load. Also the
(load) bearing points (the points which go on the crane hook)
keep changing, whilst on a webbing sling the points are fixed.
(at the "eyes" of sling) and open to wear and tear. If
these points are not inspected regularly, they could lead to
potential "weak spots" in the sling.
Q12. What are the standards SLINGSET® slings manufactured to ?
- SLINGSET®
slings are manufactured to OSHA (American Standard) AWSI/ASME B
30.9 and to British Standard BSEN 1492 - 2 - 2000 (Round Sling)
BSEN 1492 - 1 - 2000 (Webbing Sling).
Q13. How do I inspect these slings?
- Inspection
of SLINGSET® slings is easy and only visual. Follow the simple
steps.
- Lay
down the sling in a well lit area, on a flat surface (table or
ground).
- Inspect
the entire body along the length of sling. Observe for cuts,
abrasions and damage to the outer cover if any. In case any
observed, inspect of the core yarn inside has been cut or
damaged, remove the sling from service to have it inspected by
an authorised SLINGSET®
representative.
- If
your sling has a Fibre optic cable inspection system installed,
then test if the fibre optic works. If not there has been some
unseen damage to core yarn (either chemical damage or crushing).
Remove sling from service to be inspected by an authorised
SLINGSET® representative.
- Check
"overload tell tails" length. If they appear to have
shortened from the last inspection, then the sling may have been
subjected to overload. In case they have disappeared the sing
has been seriously overloaded and requires inspection by an
authorised SLINGSET® representative.
- Proof
load test the slings once in six months (or more frequently as
per your safety norms). Though this is not strictly required as
SLINGSET® slings don’t age or rust, some safety inspectors
require it.
- IMPORTANT
: Keep regular written records of all such inspections to ensure
that these are available to safety optics when required. A
format of the suggested inspection is given below :-
SAFETY
INSPECTION RECORD CARD FOR SLINGSET® SLINGS. |
SLING NO. : ______ CAPACITY (SAFE WORKING
LOAD) : _______ LENGTH: ______
TYPE: ROUND/WEBBING/TWINPATH/EYE &
EYE/MULTILEG.
DATE OF PURCHASE : _____________
DATE OF COMMISSIONING : ______________
DEPARTMENT/DIVISION : ____________
CONCERNED SUPERVISOR : ____________
SAFETY INCHARGE/OFFICER:
___________________
|
Date |
Length
observation |
Damage/
Abrasion stages |
Tell tail
length.
(in/mm) |
Fibre/Optic
working
Y/N |
Proof
load test Y/N.
If Yes, mention load. |
Remarks |
|
|
|
|
|
|
|
These cards
are provided free of cost with all SLINGSET® Slings.
- Particular
emphasis /remarks to be mentioned :
Damage/Abrasion/wear
and tear observed along length and in webbing or eye and eye
slings in the INSIDE portion of the eyes.
Stitching
loosened in webbing or twin path slings.
Condition
of tell tails and fibre optic cable.
If
core yarn is visible remove sling from service and return to
SLINGSET®.
Q14.
What is the safety factor - SLINGSET®
slings are manufactured to?
A. The safe working load specified on SLINGSET® slings is one
seventh the minimum break strength. This
means that a sling rated as 1 M.T., SWL, will break at
a minimum strength of 7 M.T. Therefore the safety factor is 7:1
Q15
Will repairing a SLINGSET® sling reduce it’s capacity?
A. It depends. If the core yarn has been damaged, then it is
possible that, we may
have to derrate the capacity of the sling or remove it from
service altogether. If the
damage is only to the outer cover then the capacity may not be
affected. However
this can only be ascertained after inspection and proof load
testing.
Q16
Can webbing slings be repaired if damaged?
A. No, Webbing slings have to be taken out of service if
damaged or cut.
Q17.
Can a Twin-Path® be used in a fitting or trunion which is less than
the slings width?
A. Yes, A Twin-Path®
Sling can fit spaces half of their catalog width with no reduction
in capacity.
More info...
Q18. What is the
difference between the Tell-Tails and the Fiber Optic inspection
systems?
A. The Tell-Tails
are overload indicators and will retract and eventually disappear
if
the sling is overloaded. The Fiber Optic determines if the
interior core of the sling has suffered chemical, heat or crushing
damage. If light does not pass from one end to the other, remove
the sling from service and send to the manufacturer for repair
evaluation.
Q19. What do I do
if both Tell-Tails are not visible?
A. Tell-Tails should
extend past the tag area of each sling. If both Tell-Tails
are not visible, remove the sling from service. Send the
sling to the manufacturer for repair evaluation.
Q20. What pin
diameter or hardware diameter is ok with a Twin-Path® Sling?
A. Slings used with
fittings shall be compatible with the fittings used. The lifting
capacity shall be rated at the lower of the sling or fitting.
Fitting openings shall be of the proper shape and size to assure
that the sling will seat properly. More
info... (pdf format, see note below)
Q21. What happens
if oil or gasoline gets on my Twin-Path® Sling?
A. Hydrocarbons and
oils do not affect the performance of any Twin-Path® sling.
Q22. Is there a
way to shorten a synthetic sling's length?
A. G-Link Connectors
can be used to shorten the length or reach of a synthetic sling. More
info...
Q23. What about
stretch? I've seen loads bounce with synthetic slings.
A. At rated
capacity, nylon slings will stretch up to 15%. Round slings made
with polyester will stretch 3%. Braided Polyester slings will
stretch 9%. Twin-Path® Extra Slings w/ K-Spec® core yarn stretch
less than 1% at rated capacity. More
info... (pdf format, see note below)
Q24. If a
synthetic round sling has one interior core yarn which has been
damaged or cut, can it still be used if the sling’s capacity is
de-rated?
A. NO! Round slings
that suffer damage to the load bearing cores must be removed from
service. These slings shall be destroyed to prevent inadvertent
use.
Q25. Are all
Twin-Path® Extra Slings proof tested before reaching the
customer?
A. Yes. As part of
our manufacturing process, each Twin-Path® Extra Sling is proof
tested to two times its vertical rated capacity. Every repaired
Twin-Path® Extra Sling is also proof tested before it is returned
to the customer.
Q26. How do I
know if a load edge is "sharp" enough to require a
CornerMax Pad?
A. The word
"sharp" is considered subjective and is no longer used
in our catalog or website. Any material can be cut when exposed to
enough pressure and a sharp edge. Diamonds, the hardest substance
known, can be split into smaller parts by skilled cutters.
CornerMax Pads must be utilized to protect the sling from all
edges and corners . For an example, press your hand against the
edge of a table. If you run your hand back and forth with some
pressure applied, you'll realize that the edge doesn't need to be
"sharp" to cut. More
info... (pdf format, see note below)
Q27. Can I use a
Synthetic Armor Pad for cut protection?
A. No. The
technology that developed the CornerMax pad is for cut protection.
Synthetic Armor pads are intended for abrasion protection or to
increase the diameter of a bearing surface. More
info...
Q28. What is the
difference between abrasion protection and cut protection?
A. Abrasion
protection is needed when the sling is wrapped around a load which
is rough, dirty or gritty. Cut protection is needed when there is
an edge or corner that the sling will come in contact with. More
info... (pdf format, see note below)
Q29. Why use a
multipart wire rope sling instead of a single-strand wire rope
sling?
A. Single strand
sling is less flexible than a multipart wire rope sling. Also, a
multipart wire rope sling provides a better D/d ratio.
Q30. Why are the
D/d ratios different for the body and the eye of Gator-Max,
Gator-Laid, Gator-Flex and T&D Ultra-Flex Slings?
A. There are 12
parts of wire rope in the loops and 9 in the body.
Q31. What kind of
wire rope will my Gator-Max, Gator-Laid, Gator-Flex and T&D
Ultra-Flex slings be made of?
A. Up to
1-1/8", 6x25 IWRC. Over 1-1/8", 6x37 IWRC is used.
T&D Ultra's are made from 7x19 GAC.
Q32. What
is the difference between a Gator-Max and a Gator-Laid sling?
A. Gator-Max is hand spliced, Gator-Laid is made
using swaged sleeves.
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