In the October 2008 issue, we evaluated efficiency and energy savings for a typical centrifugal pump ("Efficiency, Energy and Life Cycle Cost"). Many said the Energy Estimator helps when dealing with...
In the Solution to Pump Challenge #3, we touched on efficiency and energy savings by approximating energy costs. Can we do this more precisely?Pump Challenge #4 asks that you evaluate energy saved...
 Solution to Pump Challenge #2: Moving a Pump from the Bottom of a Dry Pit
In the August 2009 issue, we considered the following challenge: From the available data tables, the vapor pressure of 150 deg F water is about 4 psia, or (x 2.31) = 9 psia.Initially, when the...
In Pump Challenge #3 (Pumping Prescriptions, September 2009), the specified parameters for energy estimation were 4,000 gpm and 400 ft. Using the Energy Estimator tool, you should receive the...
In Pump Challenge #4, many of you discovered while using the Energy Consumption Evaluator, that the standard listing only goes to 8x6-17 pump size with motor power maxed at 250 hp, which is below...
10 Steps for Proper Pump-Pipe Alignment
The initial version of this procedure was published several years ago by me. Since then, a large amount of feedback has been accumulated. The most recent reflection appeared in the March 2012 issue of...
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...
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...
Facts and Fiction About Vibration
Facts can be tough—our emotions may get in the way. What we think we know is not always factual but is based on what we may intuitively feel is an undisputed truth. It is human to expect everyone...
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). ...
Multiple screw pump performance specifications are shown in the table below.Pump TypeFlow Rate GPMPressure Range PSIViscosity Range cStTwin Screw25 - 5,50050 - 1,500Gas - 1,000,000Three Screw1 -...
Pumps & Systems, July 2008Click here for "Focus on Fundamentals" Part 1, Part 2, Part 3 and Part 5. In the June 2008 issue, we turned our attention from centrifugal to positive...
This month, we begin a five-part series called "Focus on Fundamentals." These back-to-basic tutorials explore different pump types, including various centrifugal and rotary pumps. Part One focuses on...
Pumps & Systems, June 2008Click here for "Focus on Fundamentals" Part 1, Part 2,  Part 4 and Part 5. In the April and May 2008 issues, we looked at centrifugal pumps....
In the April issue, we discussed fundamentals of the overhung impeller centrifugal pump design. Its advantages are a single bearing housing and a single seal or packing, but an overhung impeller load...
Grouting: Pumps and Telephone Poles
A few years ago, Corbin Spitzer from Spitzer Associates (Houston, Texas) correctly challenged a view in my article "10 Steps to Proper Alignment" (Pumping Prescriptions, October 2005). Spitzer...
Lev Nelik answers a reader's question on thermodynamic sub-processes that are highly time dependent
How Does Pump Suction Limit the Flow?
One of the advantages of centrifugal pumps over positive displacement pumps is an ability to operate with a wide flow range. Since a centrifugal pump operates at the intersection of a pump curve and a...
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...
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...
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...
A double-suction split case pump (18-in suction nozzle size), similar to the one shown in Figure 1, moves 8000-gpm at 400-ft head in a paper mill. Before reading further, stop to make a rough guess on...
Pumps & Systems, June 2007 Last month, we discussed applications of low head axial flow pumps ("Field Testing: Theory vs. Reality," Pumping Prescriptions, May 2007). Knowing your system...