Q. What is NPSH3, and what are the methods for determining the NPSH3 of a rotodynamic submersible pump? A. NPSH3 is the net positive suction head available to a pump under test at a constant rate...
Q. What are the advantages and limitations of a sealless pump design? A. A sealless pump is used when there is a need to contain toxic, dangerous and/or valuable fluids. Application may be...
Q. When dealing with wastewater treatment pumps, what concerns pertaining to site conditions are relevant? A. The type of pump that can be used depends on the location of installation. These...
Compression packings have suffered from a reputation of being an old-fashioned technology unsuited to modern industrial processes. In the case of rotating equipment, they are largely superseded by...
Q. What are the best materials to use in pump construction to minimize part corrosion? A. Factors to consider in the selection of materials for wetted pump components include user's experience,...
This 10-year project concluded with the recent publication of recommended guidelines for pump professionals.
Q. What are some effects of a gas and liquid mixture being carried through a rotodynamic pump? A. The most dramatic effect of gas or vapor on rotodynamic pump performance is the blocking of the...
Q. What are some typical indicators of an inefficient pumping system? A. Many pumping system components are not dynamic. These components allow fluid or heat transfer, but aside from thermal...
Q. What is a regenerative turbine pump? A. Regenerative turbine pumps are characterized by a low flow rate and high head. They use peripheral or side channel vanes or buckets that are manufactured...
Q. What are some differences between specific speed and suction specific speed for a rotodynamic pump? A. The Hydraulic Institute defines specific speed as an index of pump performance (developed...
Q. We recently purchased several magnetically driven rotary pumps for our process and want to know if we need to be aware of any special operational considerations. A. The operation of magnetically...
Q. What information is available regarding bearing minimum loads for pumps? A. All rolling element bearings require a minimum applied load. This ensures that normal elasto-hydrodynamic operation...
Outside- Versus Inside-Mounted Seals, Pump Input Power & Rotodynamic Pump Motor Cooling
Q. What are the advantages of single, outside-mounted seals versus that of single, inside-mounted seals?A. Single seals have one set of sealing surfaces. The lubricant for the seal faces is usually...
Boiler Circulating Pumps, Auxiliary Cooling Water Pumps & Mounting Base for a Sealless Rotodynamic Pump
Q. What information is available regarding boiler circulating pumps for combined-cycle power plant service?A. Boiler circulating pumps circulate water within the boiler to enhance boiler operation....
Outdoor Installations, Rotodynamic Vertical Pumps & Drooping Head
Q. What is a rotodynamic vertical pump? What pumps are classified in this way?A. Rotodynamic pumps are kinetic machines in which energy is continuously imparted to the pumped fluid by using a rotating...
Q. How does axial thrust compare among different impeller types for a rotodynamic vertical pump? A. The net axial downthrust force is carried by the pump shaft. The shaft will stretch, or elongate,...
ANSI/HI 14.6 gives the pump community a globally accepted test standard 
for rotodynamic pumps.
HI Pump FAQs August 2012
Q. What is the preferred way to monitor corrosion in a rotodynamic pump?A. Corrosion monitoring is an important aspect of maintaining a pump’s reliability due to the potential risk for failure and...
PARSIPPANY, N.J. (June 6, 2012) – The Hydraulic Institute (HI), under the approval of the American National Standards Institute (ANSI), is seeking qualified individuals to participate in the review...
Hydraulic Institute Pump FAQs May 2012
Q. What are the typical causes of mechanical seal failure in rotodynamic pumps, and what are the possible leakage paths? A.  A mechanical seal is expected to achieve its maximum mean...
Hydraulic Institute Pump FAQs April 2012
Q. What is the recommended instrumentation that should be used for measuring bearing housing vibration on rotodynamic pumps?A.  For all speeds, a 6-decibel per octave filter shall be used to...
Editor's note: This first in a series is based on the opening chapter of Optimizing Pumping Systems, A Guide to Improved Energy Efficiency, Reliability, and Profitability, written by pump systems...