A factory is ready to use a centrifugal pump to send clean water at 20C to the top of an absorption tower from an open pool at a flow rate of 40m h. It is known that the gauge pressure in the tower is 1.0kgf cm2, the vertical distance from the water inlet of the tower to the water surface of the pool is 6m, and the head loss of the suction pipe and the discharge pipe are 1m and 3m, respectively. The local atmospheric pressure is a 10.33m water column and the density of water is 1000kg mod tomaso biupil or o ai ii sdw (1) There are three centrifugal pumps in the warehouse. The model and the performance parameters marked on the nameplate are as follows, select one of them for the above water supply. Model Flow rate/m h Head/m 3B57A 50 38 3B33 45 32 3B19 38 20 (2) Calculate the suction lift of the pump. NPSH/m 6.0 5.0 4.0