Page 363 - BOLA Catalogue

362
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TECHNICAL INFORMATION
Tubing - Useful Hints Bending radius
of PTFE, PFA and FEP tubing
During the assembly of devices with fluoroplastic tubing we are often confronted with the problem of how to create the smallest bending radius when the space is limited. To avoid buckling of the tubing with all its negative aspects, the following graph will be helpful to determine the smallest possible bending radius.
Take the outer diameter indicated on the horizontal axis, then follow the line upwards until it crosses with the appropriate wall thickness. From this intersection, follow the line to the left until it reaches the vertical axis which shows the minimum bending radius.
Rule of thumb for the bending radius:
outer-Ø2 = min. bending radius wallthickness
As reference value, the smallest possible bending radius can be determined by the square of the outer diameter divided by the wall thickness.
Calculation example: PTFE tubing with an OD of 8 mm and a wall thickness of 1 mm results in a minimum radius of 64 mm.
MINIMUM BENDING RADIUS
Wall thickness:
0,50 mm 1,00 mm 2,00 mm
400 R mm
350
300
250
200
150
100
50
0
5 10 15 20 25 Outer diameter in mm
Example: A PTFE tubing with outer diameter 10 mm and a wall thickness of 2 mm has a minimum bending radius of 100 mm.