High Viscosity Pumps

Positive displacement pumps such as peristaltic, progressive cavity, diapghram and flexible impeller pumps are usually selected for viscous fluids, as flow rate and efficiency is not negatively effected by viscosity.

Viscosity refers to the thickness of a fluid, or more accurately - it's ability to flow, which is measured in Centisokes (cSt) or Centipoise (cP). A high viscosity fluid is therefore a thick fluid that is considerably more difficult to flow than water which is the lowest viscosity fluid.

As viscosity determines the resistance of a fluid to motion or it's "flowability", viscous fluids need a pump that have limited frictional losses inside the pump. Whilst centrifugal pumps' flow rate rapidly declines as viscosity increases, positive displacement pumps operate very efficiently due to their internal clearances.

Some fluids' viscosity changes as their temperature does, making it important we know the temperature that the fluid is usually pumped at. For example, as oil, honey and butter get colder, they get thicker. Read our article for more information: https://www.castlepumps.com/info-hub/why-viscosity-is-critical-to-pump-selection/

We offer a range of pumps for viscous fluids, but our progressive cavity range can handle up to 1,000,000 cP and can be supplied with hopper meaning that they are able to handle products with a high proprtion of non flowing, dry content.