What is meant by priming of vertical turbine pump?

Hello, I should think, that the turbine pump needs to be filled with water, before its activation, in other Words before it is turned on. If you prime a vertical turbine pump and leave it then how do you stop all the fluid running back down the well? A foot valve would create a restriction at the inlet The answer is you provided a minimum submergance level in the sump above the first stage eye to prevent draw down and meet the NPSH required. Most VTP's are designed with cutlass rubber or other bearings that can run for short periods dry until the fluid reaches them.