| 摘要 |
<p>Valve (10) such as a ball valve with a metal seat ring assembly (25) comprising an outer ring (27) seated in the valve body and an inner ring (28) seated in the outer ring (27). The outer ring (27) is formed with a lip (30) projecting inwardly and presenting a sealing surface for contact with the valve closure member (14). The inner ring is formed with a lip (40) behind which is an annular groove (14) which permits flexing of such lip. The inner ring is seated within the outer ring. There is a small clearance between the lip and the outer ring which causes sealing between the closure member and the inner ring following by sealing between the closure member and the outer ring. The configuration and clearances of such lips is such that in initial closing the valve closure member contacts the lip of the inner ring causing it to flex and on final closing it contacts the lip of the outer ring causing it to flex.</p> |
