It can be used on engine piping, manufacture says up to 1-1/2" pipe. I would take that to mean with the low heat output, the heat will not penetrate very far. I would use armiflex insulation over heat tape wires and item being heated. http://www.emersonindustrial.com/en-...csheet_web.pdfhttps://www.youtube.com/watch?v=tZm1v12oJJM
"How much heat can they take without burning up or becoming ruined."
Sorry I do not understand this question? How much heat can what take?
Sorry, I was mistaken that the heat tape I purchased has a GFI plug. It does not, but the heat tape does need to be plugged into a grounded GFI circuit.