| 摘要 |
The valve comprises a sleeve (2) made from a flexible material and having a cross-section essentially the same as the flow channel (1). The sleeve has one end which is fixed in relation to the flow channel and one end which can rotate during a controlled displacement in the axial direction. During rotation the sleeve adopts a multi-pointed star cross-section. The valve is enclosed by noise insulating material and the tube around the sleeve is air permeable. |
