| 摘要 |
<p>BALL VALVE HAVING METAL SEAT RINGS This relates to a ball valve of the top entry non-spherical type. A soft metal coating is deposited on that portion of the seat ring which contacts the valve member or ball. The ball and seat assembly is inserted into a valve chamber such that the seat rings are in an unstressed condition. After insertion, the ball is rotated 90.degree. causing the ball to engage the soft metal coating, thereby crushing the soft metal to form a tight seal with the ball. In this manner, the lapping process, generally required when metal seats are employed, is eliminated. Further, the seats may be replaced without replacing the ball.</p> |
