| 摘要 |
According to the invention, the folded spiral-seam tube has an outer layer (21), provided with corresponding reinforcing ribs (23), and an inner layer (24) exhibiting a smooth, inner surface, said two layers (21 and 24) comprising corresponding metal strips (10 and 11) which are connected to one another in the form of a spiral, forming a corresponding connecting rib (22) in the process. This results in a single-piece, double-walled folded spiral-seam tube which, with high mechanical strength, provides a low flow resistance to media passed through it. <IMAGE>
|
