Hydrostatic draw-off valves are used for regulating the flow to the filter beds and desludging of activated-sludge or humus tanks.
Two versions of the hydrostatic bell mouth valve are available:
- the central direct lift type and the side lift type which provides unrestricted flow at the bellmouth.
- The side lift bellmouth should be used when there is a risk of clogging or ragging of the valve.
Hydrostatic valves are supplied drilled for connection to flanges in accordance with BS EN 1092-2 : PN 16.