| 摘要 |
<p>The annular cast body 1 of a butterfly valve is coated both internally and externally, including the butterfly shaft and axle passages 12, 13, with an elastomeric material 2 of the same type and hardness at all points of the valve body. The coating has a thickened band 15 which acts as a seat for the butterfly, and is molded around the valve body rather than being glued.</p> |
