| 摘要 |
<p>The invention provides a valve assembly comprising a conduit (1) with a b ore (1b) for passage of fluid therethrough. The valve assembly also comprise s a sealing member (30) that is movable within the conduit 1 to open and clo se the bore (1b). The seal assembly has a valve seat (20, 22) on which the s ealing member (30) seals when the bore (1b) is closed, and wherein the valve seat (20, 22) is movable within the conduit (1). The invention also provide s a valve assembly comprising a sealing member (30), a first valve seat (20) for the sealing member, and a second valve seat (22) for the sealing member . The valve assemblies can be resettable. The invention further provides a f lapper valve assembly wherein the flapper (30) is pivotable through more tha n 90º and a bi-directional flapper valve assembly.</p> |
