PURPOSE: To fix a tube and a tube plate in which the direction of axis of the tube does not coincide with the direction of thickness of the tube plate, by inserting the end face of the tube formed at right angles to the axial direction into the tube hole of the tube plate, welding the end face and tube plate, and expanding the fitted part.
CONSTITUTION: A tube hole is provided in a tube plate 1 in opposition to the axial direction (a) of a tube 2, and a groove 1c is formed in the fitted area with the tube 2 by performing facing 1a, 1b from both faces of the tube plate 1. The end face of the tube 2 is worked at right angles to the axial direction (a), and a notch 2b is formed on the inner edge of the end face. The tube 2 is inserted to a position slightly retracted from the surface of the tube side opposite to the tube hole of the tube plate 1, and the end face of the tube 2 and tube plate 1 are welded. Then, the whole area 2a of fitted face of the tube 2 and tube plate 1 are expanded. A this time, facing 1a of the tube hole is not always necessary, and the notch 2b on the end face of the tube is not necessary if the diameter of the innermost periphery of welding is larger than the inner diameter of the tube.
SUDOU KATSUZOU
TANI MITSUO
KAWAOKA TAKAYOSHI
