| 摘要 |
<p>Controlling fluid flow in a conduit, the lift valve uses a membrane (1) clad round head (5) piston obturator, incl. a telescopic arrangement of membrane flange (9) supports (10-13) which follow the piston. The arrangement provides continuous flange support obviating cavitation etc. The unit comprises a venturi housing (1) with a valve seat (6) and a cover (3), the latter being traversed by the piston rod (7), and the edges of the membrane flange being clamped between the housing and the cover. The support is provided to the rear membrane face and between the piston head and the clamped edges. In detail the system may use concentric sleeves (10-13) of which the walls have a 'J' or a cranked bar 'L' section in radial planes, the inner sleeve (10) following a ring (14) in a piston rod groove, and succeeding sleeves (11) following flanges on their interior neighbours (10).</p> |
