Method for making a flexible tubular pipe having a long length

• Main Authors: ALAIN DROUES, XAVIER LONGAYGUE
• Format: Patent
• Language: English
• Published: 19.02.2014
• Subjects: BLASTING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; JOINTS OR FITTINGS FOR PIPES; LIGHTING; MEANS FOR THERMAL INSULATION IN GENERAL; MECHANICAL ENGINEERING; PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; THERMAL INSULATION IN GENERAL; WEAPONS

The invention relates to a method for making a flexible tubular pipe (22) for conveying hydrocarbons, and to the resulting pipe. The method comprises: providing a sealed pressure sheath (12); providing hammer-hardened metal wires made of austenitic-ferritic stainless steel; winding, with a long pitch, said hammer-hardened metal wires around the pressure sheath (12) in order to form a tensile armor layer (16, 18); and forming an outer sheath (20) around said tensile armor layer. According to the invention, the metal wires made of austenitic-ferritic stainless steel are hammer-hardened by reducing the cross-section thereof by at least 35% in order to obtain hammer-hardened metal wires having a tensile strength higher than 1300 MPa, and then directly winding said hammer-hardened metal wires after the hammer-hardening step, whereby the hammer-hardened metal wires retain the mechanical properties thereof after winding.