F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
F16L9/00—Rigid pipes
F16L9/08—Rigid pipes of concrete, cement, or asbestos cement, with or without reinforcement
Procede de fabrication de tuyaux composites coudes a structure stratifiee comprenant au moins deux couches a base de materiaux polymeres de nature chimique differente, et tuyaux ainsi obtenus