HOW TO CORRECTLY MEASURE SINGLE
WALL HEAT SHRINKABLE TUBING
TE Connectivity Heat Shrink Tubing
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APPLIANCES /// HOW TO CORRECTLY MEASURE SINGLE WALL TUBINGHow to Correctly Measure Single Wall Tubing
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INTRODUCTION:
HOW TO CORRECTLY MEASURE SINGLE
WALL HEAT SHRINKABLE TUBING
Heat shrinkable tubing is soft and stretchable. In addition it changes shape when it is recovered
(Shrunk). This paper is intended to give guidelines on how to check the most common
measurements when measuring the dimensions of heat shrinkable tubing. Please remember
to check with Sales or Field Application Engineering if you have any specific questions about
measuring the tubing, or figuring out which type and size of tubing is correct for your application.
so they slide easily and dont hang up on fully recovered tubing. You start by
Inside Diameter (ID),
in elastomers and very flexible tubing. recovering a sample in an oven or heat
Outside Diameter (OD),
You do not want to force it in as you gun and letting it cool until you can
and Wall Thickness could stretch the tubing giving you a handle it with your hands. Then measure
false, high reading. The largest gage that the ID and OD as above. Average wall
It is important to remember, when
slides in snugly is the ID of the tubing. thickness can then easily be calculated
measuring OD or ID heat shrinkable
by subtracting the ID from the OD. You
tubing can be easily stretched. What Once you have identified the correct
can use a pin micrometer to get single
this means in practical terms is, if you ID, the OD can easily be measured with
point measurements of the wall. However,
use most traditional ways to measure a set of calipers while the plug gage
be very careful with the force applied
inside diameter you can either stretch is still inside. This will keep you from
as the micrometer can compress the
the tubing or cause it to deform to accidently compressing the tubing and
tubing causing false low readings.
be more oval than round. In both getting a false, low reading.
cases you can get an incorrect, larger Dual wall (adhesive lined) tubing needs
Wall thickness should only be measured
reading than what the true diameter to be treated differently because the
is. It should be noted that most tubing adhesive will melt and flow. Ask your FAE
does not have a maximum ID/OD for additional advice on measuring the
specification in the expanded form recovered dimensions of dual wall tubing.
(as received). It is the minimum ID
that is important before recovery, and Color
the maximum ID after recovery.
When the tubing is expanded it becomes
To get around this problem, the best INCORRECT ID CORRECT ID a lighter color. Black can become grey,
TUBING IS STRETCHED PLUG GAGE KEEPS
method involves using a set of plug red can turn more of a pink color, etc.
TUBING ROUND
gages of known sizes to determine the What this means is that the color as
ID of tubing. This causes the tubing to received may not be the final color
see uniform force all the way around after it is recovered. This is not a defect,
and prevents it from being pulled in as color is judged on the recovered
to an oval. Start with a size at the low tubing, not the as received (or fully
end of the specification and slowly expanded) tubing. A sample should
put larger and larger plug gages in the INCORRECT OD CORRECT OD be cut, fully recovered and allowed to
TUBING IS PLUG GAGE KEEPS
tubing until you find one that will not cool to properly evaluate the color.
COMPRESSED INTO TUBING FROM
go in easily. We take the plug gages AN OVAL SHAPE BEING SQUEEZED
APPLIANCES /// HOW TO CORRECTLY MEASURE SINGLE WALL TUBING