question a pump station has been designed to lift

Question

Question: A pump station has been designed to lift water out of a 6 metre deep pit (vented to atmosphere) via a centrifigual pump mounted at ground level.  

 Liquid conditions                  20⁰C 

 Suction pipe work losses       2.0 metres 

 NPSH safety factor                5.0 kPa 

 Vapor pressure @ 20^oC         0.25 metres  

Part (a) Calculate the Net Positive Suction Head (NPSH) for the system ?  

Part (b) In summer the liquid temperature rises to 60⁰C, this changes the water vapor pressure to 2.05 metres. What is the revised NPSH for the higher water temperature ?  

Part (c) Pressure loss in the suction pipe work is directly proportional to water veloicty in the pipe work squared, which is inversely proportional to suction pipe work diameter squared.