Calibrator for use in the manufacture of double walled thermoplastic pipe

摘要

In an apparatus such as a corrugator for manufacturing thermoplastic pipe with a corrugated outer wall and a smooth inner wall, a calibrator is employed to provide a smoother inner wall and a more rapid inner wall cooling. The calibrator includes a tube wound into a helical coil and an adjustment mechanism for adjusting the coil diameter. A cooling fluid may be passed through the tube.