I appreciate the feedback, sorry for not replying sooner. The initial temp of the wax is 10-20 degC, meting point of the wax is 60-70 deg C, pressure inside the pipe is 1-2MPa. Spec, your comments are very interesting; I'm also trying to heat this tube using a exothermic reaction but pressure buildup is getting in the way of that idea.
I honestly can't answer all the question because every situation would be different. My goal though would be to maintain 80 degrees of heat on this tool for 40-50 minutes. The heat transfer to melt the wax would have to be estimated.