No, you must NOT do this. The current in a parallel circuitry heater does not flow down one conductor, and back up the next - but across from one conductor to the other. If you join them together, you will cause a ‘short-circuit’. The heating tape has ‘live’ and ‘neutral’ buswires and, as you would not join ‘live’ and ‘neutral’ wires under any circumstances, you should not do this with heating tape either.