Loading patent…
AssigneeVallourec SoluçõEs Tubulares Do Brasil S.A.
InventorsJulio Marcio Silveira E Silva, Timo Ebeling, Hezick Da Silva Perdigao, Danielle Granha Giorgini, Gustavo Alves Pinheiro, Jochen Peter Ames, Antonio Wagner Da Silva Penna
Estimating the term…
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.
A process for producing a multilayer pipe by expansion, wherein the multilayer pipe comprises at least one external layer made from an outer pipe comprising a carbon manganese steel alloy and an internal layer made from an inner pipe comprising a corrosion-resistant alloy, the inner pipe having an elastic return smaller than an elastic return of the outer pipe when both are deformed and having an external diameter smaller than an internal diameter of the outer pipe;
Dependencies are inferred from the claim text.