A “Solid” Solution to Pump Selection
 Tests show that solid-body plastic pumps are the best choice for oscillating applications.The demands that oscillating-displacement pumps place on their materials of construction are extreme due...
Crane Pumps and Systems Resolves Inksters' Clogging Lift Station
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...
Centrifugal Farce & Affinity- It's All About Velocity
Why do those three affinity laws do such a good job of predicting the performance of a centrifugal pump when its rotational speed or impeller diameter is changed? Well, it turns out that they are not...
A New Way to Skin a Cat-Part 1
A Simplified Method for Monitoring Pump PerformancePump users should regularly monitor the condition of their critical centrifugal pumps to keep them operating efficiently. Otherwise, lost production,...
Hydraulic Institute Pump FAQs October 2006
Q. Due to a recent thrust bearing failure in one of our deep well pumps, we would like to determine the down thrust on the bearing from the pump. Is there a simple way of calculating this?A....
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...
Centrifugal pumps need to be kept in tip-top condition to handle harsh liquid-terminal operations.Without question, liquid storage terminals play an integral role in the ongoing success and relevance...
Hydraulic Institute Pump FAQs June 2008
Q.When measuring vibration on vertical pumps, does the allowable vibration depend on the height of the motor or on the height above the baseplate where the readings are taken?A.The allowable vibration...
Q. What are the criteria for determining the maximum allowable forces and moments that can act on a centrifugal pump's nozzles without damaging the pump? What part of a pump is most likely to be...
An Arizona mining company and an engineering pump system expert share a mutual understanding of what is needed to improve the electrowinning process that drives the copper mine's operations.Our...
Hydraulic Institute Pump FAQs March 2009
Q. How can we tell if a pumping system is designed and operated properly? Some problems such as leaking seals are obvious, but should we watch for any other symptoms?A. A few symptoms in pumping...
Pumps & Systems, August 2007Q. Is there a way of predicting the maximum operating speed for a reciprocating plunger pump when pumping a viscous liquid?A. Yes, but let's begin by setting the basic...
Vast tonnages of oil sands are now being transported as slurries in centrifugal slurry pumps as the first stage of the bitumen extraction process. Similarly sized pumps are also used to transport the...
When we start the pump selection process for a particular application, one of our major concerns is efficiency. If several different models of similar quality meet our conditions, we will usually...
Q.  Most centrifugal pumps have a horsepower characteristic curve which rises as rate of flow increases to some level and then levels off or turns downward. However, other pumps have more level...
Have you ever experienced this? The pump that you purchased for one specific performance is placed in service and operates at another point that is completely different from its original design point...
Hydraulic Institute Pumps FAQs June 2010
Balancing Pump Impellers; High Efficiency Pumps; Boiler Feed Booster PumpsA. Pump impellers are typically balanced in accordance with ISO 1940 balance quality grade G6.3 or better (see Figure B.2)....
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...
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...
Analyzing the Impeller Eye
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...
The Function of the Volute
Misunderstood pump element serves to minimize mixing lossIt is a common misconception in the U.S. pump industry that the function of the volute is that of a diffuser: to convert velocity into...
Suction-Side System Design; If You Do Not Have Enough NPSHA; Resistance of Materials to Cavitation Damage
Final Article in a 14-Part SeriesSuction-Side System DesignCentrifugal PumpsFigure 1 shows most of the features discussed below.  Straight Run Into Suction For satisfactory operation, a...
As the global demand for energy grows, power companies are working to implement new technologies that would enable them to produce more power from existing stations. The following example demonstrates...
Hydraulic Institute Pump FAQs September 2007
Q. What are the most probable causes of insufficient discharge flow or pressure in centrifugal pumps?A. Before looking at the pump, check the measurement of total head and rate of flow. The proper...
We were told that the 48-in diameter sewage pump impeller from one of New York City's main sewage pumps had been found "practically destroyed." When the impeller actually arrived at our location, both...
Hydraulic Institute Pump FAQs 2008
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....
Effects of Gas on NPSH and Example Calculations of NPSHA
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...
Hydraulic Institute Pump FAQs September 2008
Q. When operating centrifugal pumps on corrosive or erosive applications, how can the user determine when the casing wall is worn too thin for safe operation? What is the minimum safe operating wall...
 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...
Oil Sands Pump Performance Testing and Limitations
Many millions are spent in the oil sands industry providing new plants for the production of oil from tar sands. Oil sands pumps are a key component in these expansions.The cost of non-conformance can...