| 摘要 |
<p>A venting device for sanitary conduits comprising a first edge 12 and a second edge 10 bounding an air passage 7. One side of a valve 8 of flexible material is retained on the upper side of first edge 12, the other side provided with a downwardly extending ledge 13 moveably engages the top 15 of second edge 10. The valve 8 is provided with a thinned portion 9 near the first edge 12.</p> |
