Patent ID: 7297908
Filing Date: 2007-11-20
Classification: B21C,B23P,Y10T

Abstract:
1. A method for removing a tube from a tube-sheet, comprising: heating an inserted portion of the tube in a tube-hole formed in a tube-sheet, and cooling the inserted portion to reduce a diameter of the inserted portion so as to loosen the tube from the tube-hole, the tube-hole having an annular groove formed on its inner surface, the tube having a diameter-increased portion on its outer surface, and the tube-hole being engaged with the diameter-increased portion; and subsequently heating an inside of the tube, where the diameter-increased portion is formed on the outer surface of the tube opposed to the groove, to a red-hot state, while the tube is concurrently stretched in the direction to pull out the tube from the tube-hole until the tube is cut-off at the circumferential direction of the tube.