| 摘要 |
PCT No. PCT/IT90/00048 Sec. 371 Date Dec. 12, 1991 Sec. 102(e) Date Dec. 12, 1991 PCT Filed May 7, 1990 PCT Pub. No. WO90/14941 PCT Pub. Date Dec. 13, 1990.Equipment for welding pipe elements of a melt-weldable plastic material comprises a heatable metal plate and first and second heat-conductive elements attached respectively to first and second opposed faces of the plate. The first element has a concave melting surface of elliptical cross-section which is complementary in shape to that of the circumference of a manifold pipe to be heat-welded. The melting surface is raised and has a reduced wall thickness along its minor axis and is depressed and has an increased thickness along its major axis. A pipe fitting for use with the welding tool has a welding end which is substantially identical in configuration to that of the melting surface of the first element. The second element is complementary in shape to the end of the pipe fitting for melting the welding end of the pipe fitting. In a process for welding the pipe fitting to the pipe manifold using the welding tool, the heated first and second elements are brought into contact with the circumference of the manifold pipe and the welding end of the pipe fitting, respectively, until incipient melting occurs. The first element is aligned with a hole in the manifold using a non-conductive central element inserted in a central axial cavity in the first element. The melted areas are then brought into contact with each other under pressure and allowed to solidify. |
