NPSH, cavitation and recirculation - Impact and remedies

This is a rigorous course on Net Positive Suction Head, cavitation and recirculation. The course material has been compiled based on information from several handbooks, manufacturers recommendations, industry best-practice, guidelines given in norms and standards and contents of research papers and conference presentations. All the above has been blended in the light of the authors field experience.

The course focuses on the concepts and practical implications related to

• NPSHi, NPSH3, NPSHR (required) and NPSHA (available)

• Cavitation

• Recirculation

  on pumping system’s life and performance. And to learn how to

• Measure NPSH – NPSH testing, permissible tolerances

• Provide adequate NPSH margin as per industry guidelines

• Improve the NPSHA and reduce NPSHR

• Mitigate the adverse effects of cavitation, recirculation

The course comprises of 13 lecture and 6 exercises covering the topic in detail. It covers the following:

1. Definition and calculation of specific speed and the corresponding shapes of the pump characteristic curves,

2. Definition and calculation of suction specific speed and its impact on cavitation and recirculation,

3. Detailed explanation of NPSH, cavitation and recirculation phenomenon,

4. Suction Specific speed and reliability,

5. NPSH margin and NPSH margin ratio to avoid cavitation and recirculation,

6. NPSH testing of pumps,

7. Methods to improve the NPSH available,

8. Methods to decrease the NPSH required,

9. How to detect cavitation in the field,

10. Identify the operational problems through examination of the damage pattern to the pump parts,

11. How to prevent or minimize the cavitation and recirculation damage in the field.