Geodetic suction lift
The geodetic suction lift (Hs.geo) is the difference between the suction-side liquid level and the impeller's centreline.
Depending on the atmospheric pressure, water temperature and the location's altitude (measured in metres from the sea level), the theoretical maximum geodetic suction lift under ideal conditions is 10.33 m. Especially in the case of centrifugal pumps, however, cavitation will occur earlier at a suction lift of approx. 8 m due to both friction in the suction line and vapour formation. See Fig.1 NPSH