21. Vertical centrifugal pumps are also referred to as cantilever pumps. 22. The most common pool pump is the centrifugal pump . 23. It is a twin-cylinder, vertical condensing engine, driving a centrifugal pump developed by John Appold. 24. Compared to centrifugal pumps , positive-displacement pumps have several advantages. 25. Each feedpump is a multistage centrifugal pump producing 150 l / s at 21 MPa. 26. The British Transport Commission installed a centrifugal pump to maintain the statutory minimum water level. 27. There are six Byron Jackson four-stage centrifugal pumps mounted in pairs forward of the propulsion system. 28. A high-pressure condensing beam engine replaced it in 1881, which was coupled to a centrifugal pump . 29. Centrifugal pumps are far more powerful for high-density fluids but require large diameters for low-density fluids.30. Also, changes in the pressure difference have little impact on PD pumps compared to centrifugal pumps .