| 摘要 |
<p>A butterfly valve is disclosed having a circular cross-sectional flow channel, a pivotally mounted cylindrical angle-transported disc, and a packing ring placed in a groove between an expansion in the flow channel and the front face of a support ring extending to the channel opening. The outer diameter of the packing ring is smaller than the diameter of the bottom of the packing groove, and the inner diameter of the packing ring is smaller than the width of the disc in a direction perpendicular to a shaft on which the disc is mounted but larger than or equal to the width of the disc in a direction parallel to the shaft. When the valve is being closed, the disc forces the packing ring outwardly in the first-mentioned direction, causing it to be pulled inwardly in the second direction.</p> |
