the suction head in a pumping system is the vertical dimension measured from the surface of the suction tank and the axis of the pump . This height is directly related to the hydrostatic
The height of Aspiration determines the pump power and can not exceed a certain height because of the phenomena cavitation . When the maximum suction height is reached , an other intermediate pump mast be placed (or put pressure on the suction tank, reducing the temperature of the fluid ... )
The maximum height of aspiration depends on the saturation vapor pressure fluid and thus the temperature and ambient pressure .
The maximum theoretical suction height of the water( level of the sea) is about 10.33 meters. Actualy we considers NPSH pump and pressure losses due to flow of fluids.
The practical suction height max is located around 7 meters :