Apparatus for forming tapered spiral tubes from strips, is disclosed. The apparatus comprises a spiral tube forming system for forming a strip into a spiral tube; a strip infeed system adapted for feeding a strip to the pipe forming system; and computer-controlled means for continuously varying the angular orientation of the tube forming system relative to the strip infeed system to selectively vary the diameter of the forming tube. The selective variation of the diameter includes linearly tapered and curved profiles, as well as constant (unchanging) diameter profiles and combinations thereof.