FIELD: mechanical engineering. SUBSTANCE: several plastic tubes are connected by means of shaped deformed connectors running longitudinally. Tubes with connectors are turned in flat tube assembly with two outer tubes provided with device for securing the tubes in bundle; this device is shaped integral with their outer cylindrical surface. Device is made in form of covering strip shaped on one of outer tubes along shaping line. This covering strip closes clearance in tube bundle between outer tubes; covering strip is welded to free outer tube. Width of covering strip in transverse direction exceeds distance between line of shaping and weld seam by projecting part. Projecting part has limiting band fixing the covering strip in the stretched position in longitudinal direction of tubes for cable ducts. EFFECT: enhanced reliability. 4 cl, 5 dwg
