Critical Pump Selection Webinar – Video

critical pump selection three major issues webinar video

After the success of my webinar, I am making a recording of it available for everyone who was not able to attend, and those who wanted more time to go over the material and illustrations. Thanks again to everyone who attended the live webinar! If you want to hear about future webinars, subscribe now for [...]

What is the Purpose of Minimum Flow?

Chart of pump phenomena and minimum flows

Over the years use of the term “minimum flow” has evolved.   Decades ago industrial centrifugal pump manufacturers quoted a single, relatively low value for minimum flow intended to prevent users from running their pumps to destruction.  The term “minimum flow” generally meant the lowest continuous flow the pump was permitted to operate, without reference to [...]

Hydrodynamics of Pumps (2011 edition) – A Book Review

Hydrodynamics of Pumps, 2011

Hydrodynamics of Pumps by Christopher E. Brennen was first published in 1994.  Aside from my long-time professional acquaintance with the author, what caught my attention in this book are the various technical passages related to rocket propulsion turbomachines, including the Space Shuttle Main Engine.  Over the years I would hear about the technical issues with these [...]

Diffuser versus volute

Diffuser

The stator section of a centrifugal pump, after flow exits the impeller, is usually either a ‘diffuser’ or a ‘volute’. The purpose of each of these two stator types is to efficiently diffuse velocity energy into pressure. Diffusers are characterized by a plurality of radially symmetric diffusing passageways surrounding the impeller. Either a volute-shaped or [...]

Pump Handbook Fourth Edition – A Book Review

Turbine-Driven Mainline Pump: by Randal Ferman, Ekwestrel Corp

Years ago I owned a copy of Pump Handbook 1st Edition, by Karassik, Krutzsch, Fraser, and Messina.  While it was a book to have on the shelf, it was not my primary source of pump engineering reference material.  I obtained most of my pump technical information from other books and publications.  Eventually someone “borrowed” my [...]

Specific Speed – Does it Matter?

specific-speed-equation

To the pump engineer or pump manufacturer specific speed is terrifically important.  To the specifying engineer or user – maybe, maybe not. The term specific speed comes up frequently in pump literature, in technical papers and is always covered in pump text books.  It is frequently heard in pump technical banter and if one doesn’t [...]

Is there any confusion about NPSH?

double suction pump profile

Net Positive Suction Head (NPSH) is perhaps the most misunderstood concept in pumping technology.  The main source of confusion stems from multiple uses of the term in different but related contexts. One usage of the term NPSH is to denote the suction performance characteristic of the pump itself, independent of the system into which it [...]