attached are drawings for 2 stage h

attached are drawings for 2 stage high suction pressure pump and performance curve.I am expecting efficeincy to be over 50% but would like to be more conservative especially as additional wear rings clearances are required for hot application.The entire design is based on machining components from solid block.The concept is first stage - diffuser - second stage impeller and discharge volute. The volute is purposely introduced as would provide better efficiency- more uniform flow pattern.First and second stages are held by socket head cap screws as it is much easier to assembly.The design layout is done on the way to minimize axial thrust. For any difference in shaft diameter, wear rings diameters, mechanical seal sleeve diameter require axial thrust to be recalculated. I added this note beside layout drawing.