8 STAGE CENTRIFUGAL PUMP

  Multi Stage Pumps with Opposed Impellers

To overcome the high axial thrust developed by multi stage impeller, some pumps have arrangement of opposite impellers. Example is 8 stage Centrifugal Pump shown in figure below. Note how the discharge of the 4th stage is transferred by a crossover to the suction of the 5th stage. By balancing the axial thrust in this manner, the bearing can now be ball bearings instead of thrust type of bearings and the are on an oil bath rather than a pressure fed lubrication system. 

8 STAGE  CENTRIFUGAL PUMP

 

Opposed impeller design pumps are becoming more popular in multi-stage pumps because of the reduced cost, due to the reduced axial thrust.