| 摘要 |
In a flap valve, a casing is provided forming a flow opening through the valve. A flap is pivotally mounted in the casing for closing the flow opening. The casing is formed of two annular parts secured together by bolts. The two casing parts have a plane of contact with a seal secured between the two parts and extending around the opening in the plane of contact. The seal includes a pair of spaced rings with arcuately shaped seal members extending between and interconnecting the rings. Each seal member has an circumferentially extending closed hollow space forming an air cushion. When the flap is placed in the closed position in the flow opening, a slight torsional moment is executed against the seal which is formed of a wear-resistant material so that a good sealing effect is obtained. |
