Heaters with PTFE Coating for Plating Tanks
Keith Company builds Immersion Heaters with PTFE Coating for Plating Tanks - PTFE stands for Polytetrafluoroethylene. This chemical resistant “plastic” has a maximum operating temperature of 430°- 450° F. So exposing it out of solution will have a failing condition on the heater. Thermal fuses that are popular nowadays, melt the PTFE layer, and produce enough heat to open the fuse circuit - by that time the heater needs to be replaced.
Keith Company use liquid level probes that monitor the solution and turn the heater off prior to exposing it to open air.
Immersion heaters with PTFE coating are usually rated with 8 WSI (watts per square inch), so more heating elements are needed to attain the wattage output of a similar stainless or titanium heater. PTFE coated immersion heaters are used in metal finishing tanks with Hydrofluoric acids content of less than 9% by volume.
It doesn’t matter what chemical solution you put our PTFE heaters in, as long as it’s less than 200F, less than 2” from the top and has a pH of 0 to 13.
PTFE heaters can be used in any chemistry to 190°F but must have at least a 2” “no liquid zone” from the bottom of the junction box. Having the chemical solution closer to the top generates more steam and harmful vapors.
There are 3 design types available:
- 3 tube
- 6 tube
- 9 tube design
Special “L” shaped or bottom immersion heater designs are available.