| 摘要 |
<p>A ball valve includes a valve seat assembly having a lower valve seat, an upper valve seat, packings located in openings formed by apertures in abutting sides of the valve seats, and annular retainers located in central holes through the packings. Each of the components has a profiled inner surface for slidable contact with the ball controlling communication between the fluid passages in the valve box. The use of such components for the valve seat simplifies manufacture, gives a wider choice of materials to be used and reduces costs of repairs.</p> |
