CLAD PIPE MANUFACTURED BY THE MANUFACTURING METHOD, AND CLAD PIPE CONNECTED BY THE CONNECTING METHOD

摘要

The present invention relates to a method for manufacturing a clad pipe which manufactures a clad pipe, wherein inner and outer pipes of different metallic materials are coupled by drawing, and firmly connects the manufactured clad pipes; a clad pipe manufactured by the same; and a method for connecting the clad pipes. According to the present invention, a method for manufacturing a clad pipe includes steps of: preparing an outer pipe of carbon steel or stainless material; inserting the outer pipe into a first drawing mold to longitudinally form a plurality of coupling grooves on an inner circumferential surface of the outer pipe in equidistant intervals by drawing; preparing an inner pipe formed with metallic material different from the material of the outer pipe, and being inserted inside the outer pipe; and manufacturing a dual pipe by inserting the inner pipe inside the outer pipe, and forming coupled protrusion portions inserted and coupled to the coupling grooves on an outer circumferential surface of the inner pipe by inserting the outer pipe and the inner pipe into a second drawing mold to compress the inner circumferential surface of the inner pipe toward the outside to be expanded by drawing.