Pipe normally has thicker walls and may be threaded or welded , while tubing is thinner-walled and requires special joining techniques such as brazing , compression fitting , crimping , or for plastics , solvent welding .
Pipe usually has thicker walls and may be threaded or welded , where tubes have thinner walls , and needs special joining techniques such as ` brazing ' , ` compression fitting ' , ` crimping ' , or for plastics , ` solvent welding ' .