NPSH, cavitation and recirculation – Impact and remedies

How to effectively overcome the detrimental affects of cavitation and recirculation

What you’ll learn
Meaning of NPSH3, NPSHR and NPSHA in practical terms
Relationship between NPSHR, cavitation and recirculation
Factors which lead to cavitation and recirculation in pumps and pumping systems
Pumping system reliability versus NPSH margin – for pumps for different industry and applications
How to differentiate cavitation and recirculation damage and identify the root causes
Factory testing of NPSH3/ NPSHR
How to prevent cavitation or recirculation damage in new installations and pumps already installed

Requirements
Must be familiar with the basics of rotodynamic pumps
Engineering knowledge and field experience is desirable
Knowledge related to rotary machines and overall maintenance is helpful

Description
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

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

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

Detailed explanation of NPSH, cavitation and recirculation phenomenon,

Suction Specific speed and reliability,

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

NPSH testing of pumps,

Methods to improve the NPSH available,

Methods to decrease the NPSH required,

How to detect cavitation in the field,

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

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

Who this course is for
Process designers and process engineers
Persons responsible for selection, and testing and approval of equipment
Engineers and managers responsible for trouble shooting and corrective actions