| 摘要 |
PURPOSE: To provide an apparatus for butt welding a thermoplastic resin tube material having a high reliability of connecting strength. CONSTITUTION: Right cylindrical protrusions 3b substantially equal to connecting tube materials 11, 12 at the inner and outer diameters are provided at the surfaces opposed to the end faces 11a, 12a of a heater 3, the end faces of the protrusions 3a are heated in the state opposed to the tube ends, thereby concentrically heating only the tube ends, thereby making the heating state of the thickness direction of the tube uniform. |
