| 摘要 |
<p>The section (1) has multiple fold (3) that are provided in a pipe wall (2), and running parallel to each other and spirally around a pipe longitudinal axis (4), where the section is designed in an axially flexible manner and in a cross direction. The fold has a fold depth (t), and a radial distance between a fold base and a fold point of the fold lies between 5 to 25 percentages of an outer diameter (D) of the section. The section is made of soft and flexible material, plastic or synthetic filter material, in particular a filter material of polymer basis.</p> |
