Under what circumstances should a centrifugal pump not be selected?

Characteristics of centrifugal pumps, selection of operating conditions for centrifugal pumps, centrifugal pumps

Centrifugal pumps are generally characterized by high rotational speeds, compact size, light weight, high efficiency, large flow rates, simple construction, pulsation-free operation, stable performance, ease of operation, and convenient maintenance, making them suitable for a wide range of industries. Therefore, except in the following circumstances, centrifugal pumps should be selected whenever possible. So, in what situations should centrifugal pumps not be used?

When metering requirements exist, a metering pump shall be selected;

When the head requirement is very high, the flow rate is very low, and no suitable small-flow, high-head centrifugal pump is available, a vortex pump may be selected, provided that cavitation requirements are not stringent.

When the head is very low and the flow rate is very high, axial-flow pumps and mixed-flow pumps can be selected.

When the fluid viscosity is relatively high (greater than 650–1000 mm²/s), consider using a rotary pump or a reciprocating pump (gear pump or screw pump).

When the medium contains 75% gas, the flow rate is low, and the viscosity is less than 37.4 mm²/s, a vortex pump may be selected.

For applications with frequent start-ups or where priming is inconvenient, pumps with self-priming capability should be selected, such as self-priming centrifugal pumps, self-priming vortex pumps, and pneumatic (or electric) diaphragm pumps.