Thermoplastic tube, esp. for subterranean fluid transport and mfg. process

摘要

A thermoplastic tube carrying fluids comprises a smooth walled inner tube (1) and an outer sleeve (2). The outer sleeve (2) acts as reinforcement and has arc-shaped sections (3) on at least the inner surface, arranged circumferentially around the sleeve (2). Arc (3) radius is very small compared to inner tube (1) radius. Each arc-shaped section (3) forms a contact rib (5) resting against the inner tube (1). Longitudinal grooves (6) are formed between adjacent contact ribs (5). In a tube mfg. process separate extruders produce the inner tube (1) and sleeve (2) simultaneously. The arc-shaped sections (3) of the sleeve are formed in vacuum shaping and calibrating units and introduced over the inner tube (1).