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...
Hydraulic Institute Pump FAQs September 2011
Q. What are bearing isolators and how are they used?A. Bearing isolators are composed of both a stationary and a rotating component that act in concert to retain lubricant and exclude contaminants...
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)....
Hydraulic Pump FAQs April 2011
Q.  When monitoring power consumption by a pump, what measurement methods are normally used and for what purpose?A.  Monitoring the power consumed by a pump can give advanced indication of...
NPSH: A Characteristic of All Pumps
Note from Terry Henshaw:This is the first in a year‑long series of articles called Understanding NPSH. These articles were originally prepared as class notes for the all‑day seminar on NPSH...
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...
Pumps & Systems, May 2008 While complete packaged gas and dry chemical feed systems have been in the water treatment industry for many years, liquid metering pump packaged systems are relatively...
Packaged Pump Systems and Variable Flow Pressure Boosting
Packaged pump systems are gaining popularity due to their space saving design, simplified installation, single source responsibility and advanced control options with communication ability.Packaged...
Performance Curves and NPSH Tests
Editor's Note: This is the fourth article the year-long series, Understanding NPSH. To read the previous article, click here. To read the next article, click here.NPSHR Shown as a Single...
A refinery's vertical pump passes the test, verifying its performance before installation.The rotating equipment engineers at BP's Whiting Refinery in Indiana approached the support team at a pump...
Pumps & Systems, May 2007If pump cavitation is not detected and quickly eliminated, significant damage can occur to the impeller and other internal components. Since cavitation (the formation and...
Pump Curve Accuracy
Digitization methods are critical when using pump selection software.First of Two PartsMore than 150 pump manufacturers present their pump performance data electronically. These digital pump catalogs...
PumpCalcs: Be the Pump Designer
I have seen, and I am sure you have too, countless examples of installed pumps that are poor hydraulic fits. These selection mistakes are called off-design pump selections, bad actors, misapplied...
Due to high specific gravity, viscosity and particle size of mining materials, centrifugal pumps are continuously challenged in mining applications. New pump technology was created to efficiently move...
Due to high specific gravity, viscosity and particle size of mining materials, centrifugal pumps are continuously challenged in mining applications. New pump technology was created to efficiently move...
  Pumps & Systems, January 2008 Critical IssuesSERO PumpSystems GmbH is a well recognized manufacturer of side channel pumps that has been in operation for more than 100 years, but SERO...
Success Story of the Year 2009
The International Paper plant in Courtland, Ala., had experienced problems with a white water pump on a paper machine since the plant installed the pump in the late 1970s. The problem pump experienced...
Suction Calculators
Last month I reviewed an Excel-based Radial Thrust Calculator and showed how it can predict the magnitude of unbalanced radial thrust when a centrifugal pump is operated to the left of BEP. This month...
Suction Specific Speed (Part One)
The Eighth in a SeriesNormalizing NPSHOur attempts to normalize or classify water turbine hydraulic performance culminated in 1915 with the development of the specific speed concept, which was later...
Suction Specific Speed (Part Three): Using Suction Specific Speed to Establish Adequate NPSHA, net positive suction head, NPSH
Tenth in a SeriesA number of technical papers (1, 4, 7, 8) have shown that the maximum damage rate to centrifugal pumps, at least in water services, typically occurs when the NPSHA is in the range of...
Suction Specific Speed (Part Two)
Graph of Minimum Continuous FlowsIn 1982, Richard Dubner of Chevron developed a graph for use in establishing minimum continuous flow rates for centrifugal pumps (see Figure 1). It allows a lower flow...
Suction Specific Speed and Wastewater Pumps
In the February 2010 issue of Pumps & Systems, I wrote an article on my Excel-based Suction Specific Speed and Suction Energy calculators and how they can be used to predict the onset of suction...
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...
The Power of Wear Rings Part Two: Efficiency
With a 50 percent decrease in clearance, efficiency is increased by 2 to 4 percent.Part One of this series discussed how wear rings impact pump reliability by increasing rotor stability—reducing...
Definition of NPSHThe margin of pressure over vapor pressure, at the pump suction nozzle, is Net Positive Suction Head (NPSH). NPSH is the difference between suction pressure (stagnation) and vapor...
What is a Safe NPSH Margin for a Centrifugal Pump? Can You Provide Too Much NPSH?
Editor's Note: This is the fifth article in the year-long series, Understanding NPSH. To read the previous article, click here. To read the next article, click here.What is a Safe NPSH Margin for a...
Will Running Pumps Slower Help NPSH Problems?
Pumps & Systems, January 2009If your immediate answer was yes, think again-you might be surprised. Sometimes running pumps faster can actually help avoid cavitation. How so? We need to first...
A power company in the Atlanta, Ga., area wanted to replace its older, coal-fired electric generating units with gas turbine, combined cycle technology to reduce nitrogen oxide (NOx), sulfur dioxide...
For the non-expert in pump technology, selecting the most appropriate pump technology for a specific application or process system can be challenging because many of today's pumps are so...
The Eleventh in a SeriesThe Injection of Air to Reduce Noise and DamageAs stated in an earlier article, most pumps are not suitable for handling any significant quantity of free gas. (They are just...