| 摘要 |
<p>The stop- and control valve has a free cross-section corresponding to the pipe cross-section selected. It has ceramic discs surface-ground to 0.000677 to form a seal, and opened and shut by turning the transport disc over closing discs in two or more parts. The actual discs controlling the closing operation are centred on the one side in a fixed closing disc, and on the other are opened and shut by a slot in the rotating transport dis. This transport disc is surface-ground to 0.0006 mm, giving an absolutely tight seal as soon as the discs come into contact.</p> |
