Abstract: A welding method for plastic joint that will not cause a residence of the fluid and an increase in pressure loss of the fluid flow due to a bead on the inner wall in a junction part of a welded plastic joint is provided. The welding method for plastic joint (10) is a method for heat welding of a junction part (30) including the jointing faces (12, 21) which are the respective end faces of a heat weldable plastic joint (10) and a plastic tube member (20) which is heat weldable as well, being butted against each other, wherein the plastic joint (10) and the plastic tube member (20) are disposed such that the outer peripheral surface (10a) in the portion including at least jointing faces (12, 21) in the junction part (30) is exposed; a heat source (60) for welding is disposed, being spaced apart from the junction part (30); and with the radiant heat from the heat source (60), the junction part (30) is heated for welding.

Abstract: A fusion joining device for plastic tubes with which a pair of clampers 30 is supported such that it can be pivoted between the closed position where the joint portion T1 is sandwiched from both sides through a pair of members for heat conduction 20 and the open position where the spacing between the pair of members for heat conduction 20 is widened; and a pair of heaters 40 made of a resistance heat generation material in the shape of a sheet is formed such that it is along the pair of members for heat conduction 20, respectively, in order to heat the joint portion T1 through the pair of members for heat conduction 20.

Abstract: A fusion joining device for plastic tubes with which a pair of dampers 30 is supported such that it can be pivoted between the closed position where the joint portion T1 is sandwiched from both sides through a pair of members for heat conduction 20 and the open position where the spacing between the pair of members for heat conduction 20 is widened; and a pair of heaters 40 made of a resistance heat generation material in the shape of a sheet is formed such that it is along the pair of members for heat conduction 20, respectively, in order to heat the joint portion T1 through the pair of members for heat conduction 20.