摘要 |
First and second pipes having at least two concentric layers of thermoplastic material are joined to form a pipe assembly. A non-planar mating surface is prepared on the end of each pipe. The pipes are brought into abutment at the mating surfaces to form a joining zone. Each of the mating surfaces is heated and then cooled under compression to solidify the joining zone, thereby forming a weld. Preferably separate heating processes are used to melt and join the separate layers, thereby substantially eliminating the intermingling of the layers, which may be chemically incompatible. A strong, durable joint is effected in a simple and reliable manner. Optionally, a melt flow insert is disposed between the pipes being joined to provide physical separation between the volumes of the different layers that are melted during the formation of the joint. |
申请人 |
BASF AKTIENGESELLSCHAFT;KAGAN, VAL, A.;KELLEHER, JAMES, M.;VIOLA, WALTER, J. |
发明人 |
KAGAN, VAL, A.;KELLEHER, JAMES, M.;VIOLA, WALTER, J. |