Operating principle:

Prior to startup, the priming pot and pump are filled with
a chemically compatible liquid via the filling nozzle. During
the startup phase, the pump draws the liquid from the
priming pot into the discharge pipe. As a result, the suction
line is vented and the pump can lift the liquid from a level
well below the pump. After the pump has been shut down,
pressure equalization will cause the priming pot to be filled.
Sizing and monitoring options are application-specific.