Shrink Fittting Part Removal application with Induction Heating

Shrink Fittting Part Removal application with Induction Heating Objective This is a Shrinkfit Part Removal application. The customer’s current process uses a press to push the inserted part out. However, this requires significant force and time. By applying heat, the housing can expand just enough to allow for the easy removal of the inserted part … Read more

Induction Shrink Fitting Steel Tube

Induction Shrink Fitting Steel Tube With IGBT Heating Units

Objective Heating a steel tube to 500-1000°F for a shrink-fitting application. Determine expansion (growth) of ID at varying temperatures.
Material Steel tubes 7” OD x 4.75” ID x 5” heat zone
Type ‘K’ thermocouple to measure temperature
Thermal blanket
Temperature 500, 800, 1000 °F (260, 427, 538° C)
Frequency 66 kHz
Equipment DW-HF-7.5, 7.5 kW, 150-400 kHz induction power supply, equipped with a remote heat station containing two 1.5 μF capacitors (for a total of 0.75 μF)
A multi-turn, special series-parallel induction heating coil designed and developed specifically for this application.
Process Initial tests were completed on a sample without a thermal blanket. A thermocouple is slipped between the copper ring and the steel tube to measure temperature. The part measured
4.940” (at room temperature with an ID gauge.) The part reaches 1000°F (538°C) in about 10 minutes.
The chart below shows the comparison between theoretical and experimental measured results


Results/Benefits The part measures 4.975” at 1000°F yielding an expansion of 0.035” (4.975 minus 4.94). At 500 and 800°F the expansion numbers were 4.950 and 4.964 respectively. When using a
thermal blanket the heat time is reduced by about 90 seconds (8.5 minutes as opposed to 10 minutes).


Heating shrink tube







induction shrink fitting tube








Shrink Fitting Steel Tube