| 摘要 |
<p>A valve comprising a valve body and provided with a flow passage. In the flow passage is turnably or rotatably fitted an imperforate closure member, such as for example a disc or a ball calotte. When necessary, between the closure member and the valve body are fitted co-operating sealing members. On one or on both sides of the closure member is fitted one or several, punched attenuator plates or plates provided with multiple apertures, placed side by side and at a distance from the closure member and at a distance from each other.</p> |
