Soldering Brass end cap on heat exchanger

Objective

To solder a brass endcap onto a heat exchanger

End Product

heat exchanger

Equipment

Ambrell EASYHEATTM 10 kW, 150-400 kHz induction heating system equipped with a remote workhead

A dual four-turn pancake coil designed specifically for this application

Materials

Preassembled heat exchanger with copper tubes and two brass endcaps 2.36” (60 mm) OD, 0.08” to 0.12” (2 to 3 mm) thick at both ends, liquid solder

Temperature

302 ºF (150 ºC), 482 ºF (250 ºC)

Frequency

237 kHz

Testing

The dual four-turn pancake coil was used to solder two brass caps per cycle. Liquid solder was squirted onto the end cap and was heated for 18 seconds at 302 ºF (150 ºC) to burn off the flux. Then the heat was increased to 482 ºF (250 ºC) for 15 seconds to solder the parts.

Benefits

Speed: Compared to a hot plate, induction heating was able to heat two parts in 30 seconds versus one part in 60 seconds with the hot plate.

Precise, repeatable, even heating: Induction is a highly repeatable process that also offers even heating, which this process required. 

Production: The rapid speed of induction enabled them to increase their production levels. 

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