Water-Lifting Devices – Pumps - Practices of Irrigation and On-farm Water Management - page 457

of pumps. Mixed-flow impellers are often used in deep-well turbine and submersible
turbine pumps.

12.5.8 Advantage and Disadvantage of Different
Centrifugal Pumps

Table 12.2 presents advantages and disadvantages of various centrifugal pumps.
This comparison may be helpful in selecting a centrifugal pump for a particular
application.

Table 12.2 Advantages and disadvantages of various centrifugal pumps

Volute
pumps

Diffuser
pumps

Turbine
pumps

Propeller
pumps

Advantages
Available in a wide range of sizes

√ √ √ √

√ √

Simple construction

√ √ √ √

Relatively quiet operation

√ √ √

Robust with a long life

√ √ √

Available in a wide variety of materials

√ √ √

Can handle liquids containing solids

√

Can handle liquids with a high proportion of
vapor

√

Self-priming

√ √ √ √

Variable speed drive units not required to
adjust the capacity

√ √ √ √

Pressure and power developed are limited at
shutoff

Disadvantages
Unsuitable for pumping high viscosity liquids √

√ √ √

√ √ √ √

Heads developed are limited

√

Close clearances

12.5.9 Some Common Problems of Centrifugal Pumps, Their
Probable Causes, and Remedial Measures

Problem Possible causes Remedial measures

No liquid delivered - Pump not primed Prime the pump

- Insufficient available NPSH Increase the NPSHa

- Suction line strainer clogged
- End of suction line not in water Check the depth to water level

- System total head higher than
pump total head at zero capacity