The Thirteenth in a SeriesIf a centrifugal pump is started with the discharge valve open too far and with a low discharge pressure, the liquid in the suction line may accelerate at a rate that causes...
As energy costs rise and energy efficiency becomes more important in operating pumping systems, equipment suppliers, system designers and operators will maximize the efficiency of system components to...
Pumps & Systems, August 2007Conclusion of our look at a new tool that predicts how pumps and systems interact.Last month, I opened this discussion by explaining how the affinity laws are used to...
This is a follow-up to my column on predicting centrifugal pump performance (Pump & Systems, May 2011), and offers equations that will enable the engineer to perform a partial analysis of the...
Say goodbye to concerns about pump seizure: By properly applying composite materials to a troublesome boiler feed water pump, this large process facility in Alberta can now run one pump during...
The Gulf of Mexico (GOM) is one of the prime areas for the production of crude oil worldwide. The number of platforms is continuously increasing, and major oil and gas discoveries continue with...
The radial forces that form about the periphery of a single volute pump's impeller are proportional to total pump head, impeller diameter and vane width. They are seldom balanced, but they reach their...
An OEM and an end user had installed a number of large, double-suction pumps for a water pumping station project (Figure 1). Soon after, they began to suspect that the pumps were a significant...
Cavitation in pumps is a well known but unwelcome phenomenon. When imploding bubbles of pumped product undergo rapid phase transformation from liquid to vapor state, and then back to liquid, the...
When choosing a rental pump, ask yourself the following question: Would you have a general practitioner perform your open-heart surgery? Hopefully, your answer would be no. While there is a place and...
Pumps & Systems, April 2008
Biofuel production is one of the fastest growing sectors of the energy industry. To reduce our dependence on finite energy sources such as petroleum fuels and decrease...
Electric Submersible Pump Technology
Most producing oil fields utilize an electrically driven downhole pumping system to bring oil to the surface. The pump typically comprises several staged...
Pumps and Systems Success Story of the Year 2010 Honorable MentionFor several years, the City of Inkster, Mich., had daily clogging issues with the non-clog pumps at its John Daily CSO...
Pumps & Systems, May 2008In trench-type wet wells, the pump intakes are placed near the bottom of a deep, narrow trench coaxial with the inlet pipe but considerably below it (see Figure 1). The...
Do Pumps Require Less NPSH on Hydrocarbons?Yes.The extensive application of pumps to hydrocarbon services in the first half of the 20th century produced numerous observations that centrifugal pumps...
Some may question if this is an appropriate topic for a pump magazine. While I do admit that I am a staunch conservative, this column is not about the political left. Instead, it addresses a very...
Editor's Note: This is the third article the year-long series, Understanding NPSH.Effect of Gas on NPSH Effect of Dissolved Gas on Vapor Pressure Determining the vapor pressure of light...
Modifications can be made to many older pumps to improve on their original design. Pump rebuilders with experienced engineering staffs can provide these modifications and upgrades to substantially...
The total energy consumption of industrial plants is a decisive factor for a successful, economic operation. While the energy costs were once the main motivation to reduce energy consumption,...
Pumps & Systems, May 2007
How to Talk to Managers
Most financial decisions of any consequence at your facility are made by managers; Plant Managers, Project Managers, Operations Managers,...
Click here for "Focus on Fundamentals" Part Two, Part Three, Part Four and Part Five.
This month, we begin a five-part series called "Focus on Fundamentals." These back-to-basic tutorials explore...
Click here for "Focus on Fundamentals" Part One, Part Three, Part Four and Part Five.
In the April issue, we discussed fundamentals of the overhung impeller centrifugal pump design. Its advantages...
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...
Q. When pumping a liquid that has a viscosity greater than water, how can the effect of this higher viscosity on the pump performance be estimated?A. The Hydraulic Institute (HI) has...
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...
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...
Centrifugal Pumps have and will continue to be a vital player in the HVAC industry.Look at the skyline of any major U.S. city. The number of buildings is staggering. Given the fact that pumps in HVAC...
Q. Is it true that centrifugal pumps should be built with ball bearings that have greater than normal internal clearance?
A. It depends on the pump type and the conditions of service for the pump.
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Q. I have heard that the rate of flow through centrifugal pumps can be regulated by submergence control instead of by throttling the pump discharge. How does this work, and does it damage the pump?A....
