| 摘要 |
<p>The valve has a mobile seat (150) formed by a circular ring centered on an axis (X0X0) of a body and movable in sliding along the axis relative to the body so as to be applied against a fixed seat (230) of a spherical cap (221) of a large-sized spherical shutter (200). A stop (116) for stopping end of travel of opening of the shutter is placed on a path of an edge (223A) of a cylindrical passage (210) at a side of a spherical crown (220) cooperating with the mobile seat. The edge of the passage is supported against the stop in the closing position. The mobile seat is formed by a principal ring with T-shaped section receiving a wear ring that is made of nickel aluminum-bronze. The principal ring and the wear ring form a joint that is made of polyurethane.</p> |
