| 摘要 |
<p>A coupling is provided preferably for a vortex valve for use on an outlet pipe in a sewerage system. The coupling comprises an outer component for insertion into a bore of a pipe 62, and an inner component 26 which is inserted into the outer component, ramp means being provided between the two components, whereby the outer component is expanded to seal against the bore when the inner component 26 is inserted into the outer component so as to engage the second ramp portion. The ramp means comprises first and second portions 28, 30 of different inclinations. The vortex valve has a circumferential inlet 11 which is adjustable.</p> |
