However, with no obvious static head and an open discharge, there is a real chance that the discharge pipe work will act as a syphon. This can cause the liquid level in the wastewater collecting tank to empty with the pump potentially air locking when next required.
This may be avoided by carefully calculating the friction loss in the discharge pipework, then selecting a suitably sized pump whose performance curve will cross over the drawn system curve ensuring that its duty point will be left of the end of the curve.
When the selected pump is fitted with an air admittance valve this will prevent a vacuum, and therefore a syphon effect, ensuring a reliable pumping solution.
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