| 摘要 |
A ball- or plug-type control valve (10) comprising a valve body (11) defining a housing (12) for a sealing member (13) designed to define a communication passage (13') between an inlet and an outlet when the valve is in the open position, and to seal said passage when the valve is in the closed position. The sealing member (13) consists of a fluid-inflatable elastomeric pocket (16). When the valve (10) is in the open position, the pocket (16) is deflated, and when the flow through the valve is to be controlled, the pocket (16) is inflated to a greater or lesser degree by varying the pressure of the fluid fed in through a fluid supply channel (18). At pressures higher than a given pressure, said pocket (16) completely seals off the passage between the inlet and the outlet, thus closing the valve. Said valve may be used with material-loaded, fouling, crystallising and pulverulent fluids. |
