PUMPS WITH RELAUNCH
As already mentioned, the suction capacity of the pumps has a physical limit; normal wellpoint pumps can reach a maximum depth of 6-7 meters in suction and approximately as many in discharge. Below that level, they are ineffective. To overcome greater differences in height, pumps can be used in series to re-launch the water at higher heights without pressure losses.
Similarly in pumping with long discharge lines (ex. bypass), it may be useful to insert series of pumps to obtain the desired results.
