# Centrigugal Pumps

Topics: Fluid dynamics, Pump, Pressure Pages: 48 (12503 words) Published: April 12, 2013
TUTORIAL CENTRIFUGAL PUMP SYSTEMS
by Jacques Chaurette p. eng.  copyright 2005

Fluide Design Inc., 5764 Monkland avenue, Suite 311, Montreal, Quebec, Canada H4A 1E9 Tel: 514.484.PUMP (7867) E-mail: jchaurette@fluidedesign.com Web site: www.fluidedesign.com

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1. Different types of pump systems 2. Three important characteristics of a pump system: pressure, friction and flow 3. What is friction in a pump system 4. Energy and head in pump systems 5. Static head 6. Flow rate depends on elevation difference or static head 7. Flow rate depends on friction 8. How does a centrifugal pump produce pressure 9. What is total head 10 What is the relationship between head and total head 11. How to determine friction head 12. The performance or characteristic curve of the pump 13. How to select a centrifugal pump Examples of total head calculations - sizing a pump for a home owner application 14. Examples of common residential water systems 15. Calculate the pump discharge pressure from the pump total head

www.lightmypump.com---------- Revised October 9, 2007

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Appendix A Flow rate and friction loss for different pipe sizes based at different velocities Appendix B Formulas and an example of how to do pipe friction calculations Appendix C Formulas and an example of how to do pipe fittings friction calculations Appendix D Formula and an example of how to do velocity calculation for fluid flow in a pipe Appendix E The relationship between pressure head and pressure

www.lightmypump.com---------- Revised October 9, 2007

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Foreword This tutorial is intended for anyone that has an interest in centrifugal pumps. There is no math, just simple explanations of how pump systems work and how to select a centrifugal pump. For those who want to do detail calculations, some examples have been included in the appendices. This tutorial answers the following questions: What are the important characteristics of a pump system? What is head and how is it used in a pump system to make calculations easier? What is static head and friction head and how do they affect the flow rate in a pump system? How does a centrifugal pump produce pressure? Why is total head and flow the two most important characteristics of a centrifugal pump? What is meant by the pump rating? And what is the optimal operating point of a centrifugal pump? How to do details calculations that will allow you to size and select a centrifugal pump? How to verify that your centrifugal pump is providing the rated pressure or head? What is density and specific gravity and how do they relate to pressure and head?

www.lightmypump.com---------- Revised October 9, 2007

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1. Different types of pump systems There are many types of centrifugal pump systems. Figure 1 shows a typical industrial pump system. There are many variations on this including all kinds of equipment that can be hooked up to these systems that are not shown. A pump after all is only a single component of a process although an important and vital one. The pumps’ role is to provide sufficient pressure to move the fluid through the system at the desired flow rate.

Figure 1 Typical industrial pump system. Back in the old days domestic water supply was simpler...aaah the good old days. Goodnight John boy..

Figure 1a The old days.

www.lightmypump.com---------- Revised October 9, 2007

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Domestic water systems take their water from various sources at different levels depending on the water table and terrain contours.

Figure 1b Water supply sources (source: The Ground Water Atlas of Colorado). The system in Figure 2 is a typical domestic water supply system that takes it's water from a shallow well (25 feet down max.) using an end suction centrifugal pump. A jet pump works well in this application (see...