Double Volute


A centrifugal pump design that incorporates two cut waters, 180 degrees apart, to prevent shaft deflection when the pump is operating off of its best efficiency point (BEP).

The double volute lowers the efficiency of the pump a small amount and therefore is seldom used on smaller size impellers.

  • The radial force for a double volute casing is about 8% of the shut off value for the single volute casing.
  • An advantage of this design is that the second volute adds strength to the casting and acts as a return channel if the pump is throttled too much.
  • The direction of the small radial thrust in double volute casings is generally towards the casing cutwater.