A centrifugal pump is used in the plateau, the external atmospheric pressure is P0 = 8.6 mH 2 O (absolute pressure), and water at 15 °C is transported. The water vapor pressure is P V = 1.707kPa. Checked from the working point, Δh allowed = 3.5m, it can be calculated that the resistance of the suction pipe is 2.3 mH 2 O, then the maximum installation height is ()m