The KSB Group has developed a special impeller for its Movitec multistage high-pressure pumps. This new impeller significantly improves these pumps’ suction characteristics (NPSH value). It proves its worth particularly in applications with critical inlet conditions (e.g. boiler feed applications) as well as applications in which the pump is required to take in water from low-lying tanks or at higher temperatures.
Under these conditions, a pressure drop in the intake area may cause cavitation to occur in the first pump stage. This can result in excessive wear of pump parts or motor bearings as well as a reduced service life of the pump due to damaged parts and an unbalanced hydraulic system.
The new impeller is offered as an alternative to the standard product. When developing the new impeller, KSB’s design engineers went to great lengths to ensure it can be used with a number of Movitec variants without necessitating modifications to the outer pump casing.
The new impeller features a modified inlet diameter, vanes allowing a slightly diagonal throughflow and a newly designed stage casing, all of which serve to substantially improve the pump’s NPSH curve.
The multistage centrifugal pumps from the Movitec range are designed for handling fluids such as water, coolants, condensate and mineral oils. They are ideal for a wide variety of applications ranging from industrial boiler feed installations in steam circuits, recirculation and fire-fighting systems, cooling water circuits and washing plants to pressure boosting in general process applications.
Picture: The new impeller from the Movitec type series substantially improves pumps’ suction characteristics (NPSH value). (Image: KSB, Frankenthal)