Upthrust (Vertical Turbine Pump)

In vertical turbine pumps, there is normally a net thrust load that pulls the pump rotor downward.  However, at very high flowrates, such as at flows at the end of the performance curve, the magnitude of the upthrust force acting on a vertical turbine pump rotor can exceed the value of the all downthrust forces and result in a net upward rotor load. The pump motor’s bearing assembly must be designed to handle both downthrust and upthrust situations.