The conventional technique to join a saddle to the side of a pipe consists of
simultaneously heating both the external surface of the pipe and the matching
surface of the saddle type fitting with concave and convex shaped heating tools
until both surfaces reach proper fusion temperature.
The Plastics Pipe Institute recommends that saddle fusion joints be made only with a mechanical assist tool, providing proper alignment and force control, unless hand fusion is expressly allowed by the pipe and/or fitting manufacturer