Selection of Pumps for High Viscosity Liquids: Centrifugal Pumps or Screw Pumps?

[@dheyaalgallaf6060]

Does the head curve ( not P) changed by viscosity changed, how the vendor accomdate it while his pump running by water only?

[@SPEC786]

The theoretical head -capacity curve does not change with the nature of the liquid being pumped. Head is function of only machine parameters such as impeller dia, blade angle , rpm. The actual shape of the curve depends the liquid properties such as density and viscosity. These properties particularly viscosity have significant impact on the frictional and other losses within pump fluid passages. If you are specifying a liquid whose viscosity is significantly different from water, you should inform the vendor to provide the curve for the specified liquid. He will provide the characteristics.

[@dheyaalgallaf6060]

@Viking Pump thanks for your feedback, i am slightly confused, if engineering company design a centrifugal pump for viscosity other than water (i.e. other fluid) how to link this pump with a vendor pump tested by water only!

[@SPEC786]

Once the vendor supplies documents related to the pump to the customer or the engineering company who acts on behalf of the customer, he only looks into the pressure and shaft break power. Both these parameters are direct function of density. He can convert these data easily from water run data. Also important is NPSH required. He doesn't relate to the viscosity at this point. Viscosity and shaf break power is included in the pump specification sent to the pump supplier for him to design the pump. Vendor has to meet these requirements.

[@SPEC786]

The pump supplier has also to meet the efficiency specified in the data sheet