1. Welded Tee: A type of tee fitting that is welded to the connecting pipe parts.

2. Socket tee: A type of tee pipe fitting where the connecting pipe is inserted into the ends of the tee and then welded or fused.

3. Clamp-style Tee: A type of tee pipe fitting where the ends are clamp connections, which are secured after the pipe fitting is inserted.

4. Threaded Tee: A type of tee pipe fitting connected to pipe components via threading.