Pump Impeller matched to casting for high efficiency and low NPSH. Fully open, has partial shrounds for maximum vane support without high thrust inherent in closed impellers. Stuffing box pressure reduced and entrance of solids prevented by back pump-out vanes. Large smoothly contoured flow passages combine best slurry and solid handling ability. Impeller is locked on shaft with impeller lock-nut and are sealed by Teflon (PTFE) gasket. State of the art casting methods provide smoothest possible surfaces for highest efficiency. All impellers are statically balanced.