# centrifugal pump

Topics: Viscosity, Fluid, Liquid Pages: 0 (3064 words) Published: September 2, 2014
PDHonline Course M102 (2 PDH)

Selecting a Centrifugal Pump
to Handle a Viscous Liquid

Instructor: Randall W. Whitesides, PE

2012

PDH Online | PDH Center
Fairfax, VA 22030-6658
Phone & Fax: 703-988-0088
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An Approved Continuing Education Provider

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PDH Course M102

www.PDHonline.org

Selecting a Centrifugal Pump to Handle a Viscous Liquid
Randall W. Whitesides, P.E.
Introduction
This course provides the student with an understanding of fluid viscosity and its effects on the performance of centrifugal pump operation. The different types and interrelation of viscosity values are discussed. Most importantly, it presents the established means to convert water standard pump performance curves so that they can be used to select or size pumps in viscous liquid service. Equations are provided to enable the student to estimate the flow, pressure, efficiency, and power required for a given pumping application.

Content
What exactly is viscosity anyway?
Viscosity is a measure of a fluid’s resistance to flow and molecular shear. Students interested in gaining a more in-depth, scientific explanation of viscosity are invited to visit: www.uvi.edu/Physics/SCI3xxWeb/Plumbing/FluidDynamics.html.

There are a number of subjects covered at the above website. Scroll down the page until the section entitled Viscosity is displayed.
In reality, all that is practically important as
it relates to this course is that fluid viscosity
affects a centrifugal pump’s performance.

Viscosity is an elusive fluid parameter partly because of the layman’s oversimplification of the physical phenomenon. Consider the following two common examples:

Selecting a Centrifugal Pump to Handle a Viscous Liquid
© 2002-2011 Randall W. Whitesides, CPE, PE

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PDH Course M102

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1. The adage blood is thicker than water imparts...