PROCESS FOR PRODUCING A MULTILAYER PIPE BY EXPANSION AND MULTILAYER PIPE PRODUCED BY SAID PROCESS

• Main Authors: SILVEIRA E SILVA JULIO MARCIO, DA SILVA PERDIGAO HEZICK, ALVES PINHEIRO GUSTAVO, AMES JOCHEN PETER, EBELING TIMO, GRANHA GIORGINI DANIELLE, DA SILVA PENNA ANTONIO WAGNER
• Format: Patent
• Language: English
• Published: 21.07.2016
• Subjects: AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKINGWITHOUT ESSENTIALLY REMOVING MATERIAL; BLASTING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; JOINTS OR FITTINGS FOR PIPES; LIGHTING; MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES,OTHERWISE THAN BY ROLLING; MEANS FOR THERMAL INSULATION IN GENERAL; MECHANICAL ENGINEERING; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; PIPES; PUNCHING METAL; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; THERMAL INSULATION IN GENERAL; TRANSPORTING; WEAPONS

A process for producing a multilayer pipe by expansion is disclosed, with or without heating, in which a multilayer pipe (1 ) comprises at least one outer pipe of metallic material (10) and an inner pipe of metallic material (20), the inner pipe of metallic material (20) having a yield strength lower than the yield strength of the outer pipe (23) and an external diameter smaller than the internal diameter of the outer pipe. The process for producing the multilayer pipe comprises a mounting step (34) between the pipes (10, 20), wherein the inner pipe is inserted inside the outer pipe, and at least one mechanical expansion step (36), comprising moving a mandrel (2) longitudinally and internally in the inner pipe (20) while the outer pipe and the inner pipe are held at a fixed position, wherein at least part of the mandrel (2) has a greater external diameter than the internal diameter of the inner pipe. When the pipes are subjected to a process of cold expansion, a "lined pipe" is obtained, which is characterized by mechanical bonding between the pipes. When the pipes are subjected to a process of hot expansion, a "clad pipe" is obtained, which is characterized by metallurgical bonding between the pipes.