| 摘要 |
<p>A valve assembly (10) of the type providing bypass flow through a branch channel (20) when the movable valve member (40) is in the closed position to block flow through the main flow channel outlet (16). A venturi device (44) is disposed in the main channel (14) upstream of the movable valve member (40), and the venturi (44) has secondary ports (58) provided through the wall at the throat section. When the movable valve member (40) is in the closed position, flow into the venturi (44) exits at the flow ports and flows through the bypass channel (20). When the movable valve member (40) is in the open position, flow discharges from the venturi (44), through the main channel (14) outlet port downstream of the movable valve member (40), thereby causing reduced pressure at the venturi throat and preventing flow through the secondary ports (58) to the bypass channel.</p> |
