Should you use a Teflon-coated immersion heater?

We are heating a chemical solution (liquid iron phosphate with fluoride acid) that is very aggressive -- it has destroyed our stainless steel heaters. A Teflon-coated immersion heater was suggested, but we need one that can handle 18,000 W, 480 V, and 22 A or less. Is this the best type of heater to survive this environment? -- R.C.

An over-the-side or bottom-style heater can be used in this application. Your tank dimensions will determine the heater configuration. -- Bruce Gemmell, Process Technology, (800) 621-1998.