Technical Informations / Bending Diameter

Maximum bending diameter for PE pipes:
HDPE Class Perimeter Tension N/mm2
PE 63 5
PE 60 6,3
PE 100 8

For acceptable small bending diameter, it should not fell below the values given in the below table.

BENDING DIAMETER FOR PE PIPES

Pipe Raw material Fall heat Acceptable Small Bending Diameter
(mpa) (mpa)
PE 80 ve PE 100 20 °C 30 x da 20 x da
PE 80 ve PE 100 10 °C 50 x da 35 x da
PE 80 ve PE 100 0 °C 75 x da 50 x da

da : Pipe external diameter

While calculating the bending diameter for pipes with fine wall, critical point is breaking possibility.  For pipes with thick wall, while calculating diameter for bending process, stretching and shrinkage limit entails the critical point.  Below formulae is used when calculating the acceptable diameter in the pipes with fine walls (by taking the breaking into account):

  • rm : Average pipe diameter (mm)
  • s : Wall Thickness (mm)

Below formulae is used when calculating the acceptable diameter in the pipes with thick walls (by taking stretching-shrinkage into account):

  • ra : Pipe external diameter (mm)
  • ε : Stretching- Shrinkage (%)

BENDING DIAMETERS OF PE PIPES ACCORDING TO SDR

Pipe Order SDR Acceptable Bending Diameter
1 41 50 d
2 33 40 d
3 26 30 d
4 17,6 20 d
5 11 20 d
6 7,4 20 d

In the operation heats below 0°C, for acceptable bending diameter, 2.5 must be added to the values stated table above.  
In the operation heats between 0° and 20°C, acceptable bending diameter is found with the interim value identification (ratio) method.