PIPE EXPANDING METHOD BY EXTRUSION OF PIPE EXPANSION BOUNDARY PART

摘要

PURPOSE:To eliminate the clevis part of a heat transfer pipe with the complete adhesion of the heat transfer pipe and the wall face of the pipe hole of a pipe plate by expanding the un-expanded part with moving of the heat transfer pipe to the fixed position after adhering the expanding part to the pipe hole wall face of the pipe plate by expanding the center part of the heat transfer pipe which is passed with projection from the pipe plate. CONSTITUTION:A heat transfer pipe 1 is projected from the pipe side face of a pipe plate 2 by passing it into the pipe hole of the pipe plate 2 and the center part of the heat transfer pipe 1 is expanded with comparatively small force. The length in the expansion may be over the whole thickness of the pipe plate 2 or on one part close to the body side end of the pipe plate 2. The expanding part which was inside the pipe plate 2 close to the body side end of the pipe plate 2 is pushed out to the outer part of the pipe plate 2 by moving the heat transfer pipe 2 to the fixed position and the clevis part is eliminated at the body side of the pipe plate 2. The re-expansion is then performed on the heat transfer pipe 1, which is adhered to the pipe plate 2. The clevis part is thus eliminated and the damage on the heat transfer pipe from the body side can be prevented.