FIELD: process engineering.
SUBSTANCE: invention relates to making continuous dual-wall tube with corrugated section and coupling section. Fabrication is carried out by extruding external tube Sa and internal tube Si in forming pass 10 with at least one section with corrugated forming surface and at least one section with preferably smooth cylindrical surface of forming aforesaid coupling. Form coupling section, external tube is extruded into coupling forming surface to get in contact with coupling forming surface. Internal tube Si is extruded into external tube Sb that stays in contact, over all axial length of coupling surface and moved in contact with external tube inner surface.
EFFECT: simplified process, reliable fabrication and joint.
9 cl, 7 dwg
