Easy Heat AHB-180 Water Pipe Heating Cable 80 FeetTemperature controlled cable runs straight along pipe and valves, held in place by application tape and plugs into grounded electrical outlet. For odd lengths of pipe over 3 4 inch in diameter, we recommend two separate cables on opposite sides of the pipe with up to 3 feet of overrun at center of pipe run. Metal pipe requires 1 2 inch fiberglass insulation around cable. For plastic pipe, its recommended wrapping pipe with aluminum foil before cable