Rotational friction welding of a sleeve connector between crosslinked polyethylene pipes by inserting a sleeve of similar material between the pipe ends and rotating

摘要

The sleeve connector comprises either a tube section, a butt welding sleeve(3) or an injection molded overlapping rotational welding socket of cross-linked polyethylene. The connector is positioned between the non-rotating pipes(1,2) and rotated about its axis while both pipes are moved axially towards each other to effect friction between the end faces(4,5,6,7) of the connector and pipes and produce a rotational friction weld. Preferred Features: With increasing frictional pressure the temperature of the mating faces(4-7) reaches 420-440 deg C to give a uniform melt viscosity. The friction period is 7-12s and when friction ceases an axial pressure of 0.9-1.2bar is applied to the joint until the melt cools.