| 摘要 |
There is disclosed a butterfly valve having a body connectable in a flowline and a seat which lines its inner side, and a disc which has stem portions at its opposite ends closely received within openings in the seat and body to permit the disc to be rotated between opened and closed positions. A ring which is restrained from movement with one of the disc and seat in a direction transverse to the stem portions substantially fills a groove in the other of the disc and seat which surrounds each stem portions so as to seal between the seat, disc and such stem portion.
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