| 摘要 |
<p>The manhole cover (1) has a locking system (10) for opening and shutting the cover as well as a sealing around the outer perimeter area (3) of the cover~s base body (2) or around the inner edge (9) of the tank opening, and which has a seal ring (8) to enable a clean and resistance-free cleaning of the cover. The base body is built as a bevelled shape with a conical outer perimeter area, whilst the seal ring is located in a groove (5) in the outer perimeter area or in a groove of the conical inner edge, with the outer perimeter area of the inner edge lying in a stop (21) around the cover. The stop may have a projection either on the outer perimeter area or the inner edge of the tank opening. The stop may have a cross-section that is corrugated, rectangular, trapezoid or semi-trapezoid.</p> |
