| 摘要 |
<p>Ball valve comprising an external containment body (11), inside which is arranged a ball which serves as shutter element (13) for fluid shut-off, said ball having a passage hole (18), being movable between a closure position and an opening position of the valve and cooperating with one or more seats (12) providing for seal elements with respect to the containment body (11) and to the ball (13). The said ball (13) provides for yielding zones (15a,15b) in its spherical portions (15), said yielding zones being disposed downstream of the said seats with respect to a pressure zone.</p> |
