Description: Rotor resonant frequency calculated assuming that the rotor is supported only in the bearings and that the bearings have infinite stiffness; Name: crit speed (dry)
Description: Rotor resonant frequency calculated considering the additional support and damping produced by the action of the pumped fluid within rotor  ; Name: Wet critical speed
Description: amount of the absolute value of the total head above the head, equivalent to the vapour pressure of the liquid at the particular temperature, with reference to the NPSH datum plane; Name: net positive suction head