US Patent 7297908 Removing method of tube

The present invention provides a removing method of a tube. Upon removing a tube 3 increased in diameter and fixed to a tube-sheet 1, an inserted portion 3a which is fixed to a tube-hole 2 of the tube-sheet 1 is heated and then cooled, thereby reducing its diameter. The inserted portion 3a is loosened from the tube-hole 2. Then, a region 3h opposed to a groove 4 formed in an inner circumference of the tube-hole is heated to a red-hot state, and the tube 3 is stretched in its axial direction, the red-heated region 3h is stretched to reduce its diameter and cut the region 3h, thereby pulling out the tube 3 from the tube-sheet 1.