| 摘要 |
<p>A fluid flow control device (26, 28) comprising a guide member (30) to guide a fluid passing through a duct (22, 24, 76), the guide member (30) being movable between first and second positions; and an urging arrangement (32) capable of providing an urging force (F1) to urge the guide member (30) towards the first position, characterised in that the urging arrangement (32) is a resilient torsion bar that is formed so as to allow the guide member (30) to be moved towards the second position by a pressure force (F2) exceeding and opposite to the urging force (F1), the pressure force (F2) being provided by a pressure difference across the guide member (30).</p> |
