Thermoplastics pipe with mandrel wound tape integral sleeve - has built-in annular seal fitted on to secondary mandrel and fused with tape

摘要

Mfr. of pipes or tubes with insertable end and sleeve-type end from helically wound thermoplastics tape(s) comprises heating the tape(s); winding it (them) overlappingly or abuttingly about a profiled mandrel; pressing upon the profile; and welding along the winding seams with application of heat and pressure. In the region of the sleeve end the tape is wound about =1 ring seal fitted upon the mandrel and serving as shaping profile. As the tape material reaches its m.pt., the ring seal is incorporated and anchored into it to form an integral composite and finally removed from the mandrel together with the resulting wound pipe or tube. Highly stress-resistant ring seal(s) are built into the wall of the prod. in one relatively simple operation, thus dispensing with prior-art separate fitting of seal(s).