PURPOSE: To perform on-site piping work promptly and securely by a method wherein when the molten surfaces of a mother pipe and a branch saddle are pushed to each other both of these surfaces are rubbed together several times completely to drive out the air absorbed into the molten surfaces.
CONSTITUTION: Both of the external peripheral surface of a mother pipe A of synthetic resin supported by a clamp device and the bonding surface of a branch saddle B of synthetic resin supported by a holder 4 are welded with a hot plate D between them. Then, the hot plate D is removed, a torque wrench 7 is brought into actin, a lifter 5 is driven pressing the branch saddle B to the mother pipe A at a constant pressure and a welding device C is allowed to be oscillated vertically centering the mother pipe A through a rotary member 14. The molten surfaces of the mother pipe A and the branch saddle B are rubbed together in the peripheral direction of the mother pipe A to drive out the air left between the molten surfaces. The molten surfaces are kept under a constant pressure and for a specified time as they are kept still.
NAKAMURA RIYUUICHIROU
KOIKE AKIRA
