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...
Hydraulic Institute Pump FAQs March 2011
Q. I am aware that there are requirements for the inlet piping of rotodynamic pumps. What are the requirements for the discharge piping of a pump?A. The maximum velocity at any point in the outlet...
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...
Pumps & Systems, October 2008Q.What is a free standing baseplate and when should it be used? Are there any special design requirements?A.A free standing baseplate is designed to properly support a...
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...
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...
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...
The concept of “suction energy” was developed to enhance the evaluation of the NPSH characteristics of centrifugal pumps, but I fear that it misses the mark. Suction energy is defined as the...
Magnetic Couplings, NPSH Margin &  Reverse Runaway Speed
Q. What are the effects of increasing temperature on the magnetic couplings in a rotary sealless pump?A. Eddy currents in the containment shell are one source of heat in a sealless pump. Heat is also...
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...
Net Positive Suction Head: NPSHR and NPSHA
In Pumps & Systems January 2007, I wrote an article about cavitation and how a collapsing water vapor bubble can damage an impeller. Since then, I have received a number of requests to address Net...
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...
Q. What is NPSH3, and how does it relate to the NPSHR for a rotodynamic pump? A. The Hydraulic Institute defines the required net positive suction head (NPSHR) of a pump as the net positive suction...
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...
After reading two of my articles on power pump valves, valve springs and net positive suction head required (NPSHR), Brazilian engineer Ricardo Martuscelli emailed me to suggest that I create graphs...
Pressure gauges are inexpensive components that can predict the causes of poor reliability in centrifugal pumps and prevent costly repairs and downtime.
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...
This is the first article in a four-part series. Four part 2, click here. Second only to electric motors, centrifugal pumps are usually the simplest machines in a typical process plant. Pumps...
Q. Can rotary type pumps be used to pump slurries? If so, should users be aware of any special precautions? A. Rotary pumps may be used to transfer slurries when the application dictates....