Back-to-back impeller pump
Back-to-back impeller pumps have multiple impellers mounted back to back on a common pump shaft. This is an effective way to balance the axial thrust that occurs during the operation of the centrifugal pump without the need for a separate balancing device. The axial flow approaches the corresponding pair or set of impellers from opposite directions.
This design is suitable for double suction pumps, such as centrifugal pumps with double inlet impellers. It can also be used for multi-stage pumps, such as pipeline pumps or boiler feed pumps.
The necessary crossover channels require axially split pump casings. Since this type of housing tends to be quite long and relatively expensive, back-to-back impeller pumps should only be used in the following situations, that is, more than one pair of impeller pumps, if a malfunction or corresponding damage (for example, balancing equipment) proves this The cost is reasonable.