| 摘要 |
<p>This ball valve prevents leak out of powder and granular material from the clearance between a seat ring and a valve body which is considered to possibly occur when a type of a ball valve moving the seat ring away from or closer to the valve body is used to pneumatically transport the powder and granular material, thereby eliminating a phenomenon in which the leaked powder and granular material bites into the sliding clearance around the valve body. The ball valve which has the seat ring (5) to block the sliding clearance around the valve body (4) by being pressed against the valve body (4), the seat ring (5) being moved away from the valve body (4) during opening or closing operation of a valve part, is provided with a purging ring (8) which surrounds the outer circumference of the clearance generated between the valve body (4) and the seat ring (5) moved away from the valve body, and jets externally-supplied air toward the clearance.</p> |
