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...
Newtonian and Non-Newtonian Fluids
How viscosity affects centrifugal pumpsThe Hydraulic Institute published a standard to account for the effects of viscosity of centrifugal pump performance. Effects of Liquid Viscosity on Rotodynamic...
Do Vibration Measurements Depend on Probe Placement and Probe Type?
Typically, vibration measurements are taken with a handheld accelerometer probe in four places:Pump outboard bearing housingPump inboard bearing housingMotor inboard bearing housingMotor outboard...
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,...
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...
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...
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...
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...
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...
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...
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...
Parallel--Not So Parallel--Operation
Using pump system analysis, from simple to the complexMultiple pumps operating in complex systems can be synchronized and controlled by a computer. In this column, I will discuss several simplified...
Pump System Design
Last of Two Parts
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...
These days, the importance of a fresh water supply and safely-treated wastewater return to the river cannot be overemphasized. No matter how hard we try, we are still a long way from the most...
Part 1 (Pumps & Systems, August 2012) discussed an example in which neglecting corrections for velocity head and gauge elevation did not introduce significant errors in the calculations. Part 2...
How Important Is Accounting for Velocity Head and Gauge Elevation? (Part 1 of 2)
For a quick estimate of pump head in the field, the discharge pressure gauge is read. This number is multiplied by 2.31, and operators can get a rough value of the pump head. If the gauge reading is...
This article will discuss a case of how measuring vibration can help detect cavitation issues. It will also show how this can relate to a bigger problem at the plant. Sometimes a proposed change of...
There are many indications that end users should not use a valve for flow control—or at least not to extremes.