One of the claimed advantages of centrifugal pumps over positive displacement pumps is their ability to operate over a wide range of flow rates. Because a centrifugal pump operates at the intersection...
Regarding the vibration spectrum on page 12 of the February 2016 issue of Pumps & Systems ("Using Pump Efficiency Monitoring to Make Faster Decisions," Figure 1, see image below and read the whole...
When a pump operates far from its best efficiency point (BEP) flow—either to the right or to the left—vibration, cavitation, overload and damage to the equipment can result. The letter below is an...
In 2015, I wrote a series for Pumps & Systems titled "Efficiency Monitoring Saves Plants Millions." (Read the whole series here.) I gave readers a real-world example of the importance of understanding...
If it sounds like cavitation, feels like cavitation and is believed to be cavitation, it may or may not be cavitation. The "cavitation" noise we often hear from problematic pumps results from bubbles...
Last of Four Parts Editor's Note: While running a pump at its best efficiency point saves money, reduces downtime and improves performance, many plant managers are unaware of how their equipment is...
Part 3 Editor's Note: While running a pump at its best efficiency point saves money, reduces downtime and improves performance, many plant managers are unaware of how their equipment is actually...
While running a pump at its best efficiency point saves money, reduces downtime and improves performance, many plant managers are unaware of how their equipment is actually performing. This series,...
Editor's Note: While running a pump at its best efficiency point saves money, reduces downtime and improves performance, many plant managers are unaware of how their equipment is actually...
Lev Nelik answers a reader's question on thermodynamic sub-processes that are highly time dependent
I received many comments from Pumps & Systems readers on "How to Calculate Pump Specific Speed" (Pumps & Systems, January 2015) and "How Efficient Is Your Pump?" (Pumps & Systems, February 2015). ...
Increased efficiency means more money saved on energy. When competitive bids are evaluated, efficiency is an important factor, especially for high-energy pumps. A single point of efficiency could...
Last year, “Reduce Thrust and Extend Bearing Life” (Pumps & Systems, December 2013) discussed the benefits and some potential pitfalls of adjusting the axial clearance of American National...
I received a lot of feedback on my column “How Much Energy Do Pipes Remove?” in the September issue of Pumps & Systems. This column described the use of two computer programs that evaluate the...
In past “Pumping Prescriptions” columns this year, I have discussed the procedure of piping size selection when given the process flow requirement and how this affects the pump’s power...
When the pump selection process starts, the required flow of the is often the only known variable for an application. For example, a system must move 2,000 gallons per minute (gpm) from a holding tank...
One of the supposed advantages of centrifugal pumps when compared to positive displacement pumps is their ability to operate across a wide flow range. Because a centrifugal pump operates at the...
First of Two Parts Cavitation can severely damage pumps and is affected by pump design and system issues. What affects it most? Does the suction behavior from the discharge side (system) of a pump...
There are many indications that end users should not use a valve for flow control—or at least not to extremes.
This article was written in response to the following question from a reader: Could you explain how an ANSI pump impeller’s clearance setting (both an open-vane impeller with back pump-out vane...
Pump designers know that designing a complex pump is easier than designing a simple one. Having my own roots in design, I know how tempting it is to add another feature and a tweak to a pump design....
Resonant Frequencies
Last of Two Parts