Minimum Bend Radius: As a rule of thumb, the minimum centerline bend radius for heat pipes is three times the diameter. The example below illustrates this calculation for a 5mm heat pipe.
Angle Flexibility: Heat pipes can be bent at any desired angle. Moreover, complex and compound bends can be achieved with relative ease.
Transitioning Between Features:
- For consecutive bends, the transition distance between each bend can be zero.
- When flattening sections of the pipe, they should typically be about one-third to one-half of the original diameter.
- When transitioning from a round to flat shape, allow a space approximately equivalent to the heat pipe’s diameter.
Procedure for Flat Plane Bends: Begin by bending the round heat pipe into the desired shape, then flatten it. This is true for bends along the narrow or wide plane.
Wall Thickness Consideration: It’s possible to have a bend radius smaller than the standard recommendation if the heat pipe’s wall thickness permits. However, be cautious: this may lead to wrinkling inside the bend area, compromising the pipe’s integrity.
Performance Implications: Remember, the performance of heat pipes can be influenced by the number of bent and flat areas introduced. Typically, there’s a performance decrease of around 10% to 15%. Both the maximum heat transport capacity (Qmax) and the ability of the heat pipe to work against gravity will be affected.
