Heat Tracing Cable for FRP Dual Containment Tank

There is such a thing as wet location heat cable, but I don't know if it would meet these stringent conditions. Two brands are Frostex and Chemelex. You might try to contact the factory or a rep to ask what they can do.

Failing that, can you consider some other alternatives, such as a warm water/glycol or steam loop using corrosion resistant tubing? If it hasn't been contemplated already, insulating the tank would be good also.

Thanks for the info!

Yes, the tanks will be actually insulated, I forgot to say, with 2" of polyurethane foam right on top of the heat tracing cables that will seat on the inner tank. The cables have to be designed for maximum 180F otherwise will burn the FRP tank.

It is unlikely that heat tracing tape on its own will achieve the heat input required to stop the tank from freezing at those sorts of temperatures. Tanks are generally designed to maximise the volume stored per unit area of containment structure, whereas tapes are intended for areas where this parameter is much lower.

Generally, tapes tend to be of relatively low power output for that reason, and while a tape could be found easily that satisfies the immersion and corrosion resistance parameters, it may be that a thermostatically-controlled heater element, be it driven by steam, electricity or whatever, placed inside the tank through a flange would give a better performance than a tape.

Whatever happens, increasing the lagging thickness is always a good idea.