net positive suction head

Last of Two Parts

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...

1)  Only select pumps with suction specific speeds less than 11,000-less than 9,000 is even better.2)  Select your pump so it never operates below 70 percent to 80 percent of its best...

Pumps & Systems, July and August 2007  A review of traditional metering pump designs, along with a look at some of the new technologies that are being introduced. The metering pump is a...

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...

In this installment of “Pumping Prescriptions,” I have a quiz for our readers. A typical pump system is shown in Figure 1. A centrifugal pump delivers 200 gallons per minute of water from an open...

There are two largely accepted facts about mining: 1) A mine's landscape is dynamic, and 2) Within that landscape, water is a mine's worst enemy. Navigating a mine's landscape with pumps designed to...

Pumps & Systems, July 2008Plastic is one of the most widely used materials in the manufacturing of everyday products, including food containers, toys, computers, medical equipment, building...

Pumps & Systems, March 2007Q.What are the key requirements for good suction piping design for rotodynamic pumps?A.  Good suction piping design must eliminate air entrainment in the liquid,...

Analyzing the poor repairs on a boiler feed pumps and how they affect the pump's performance and reliability.It is often said that a picture is worth a thousand words. This old adage could not have...

Q.We have recently installed several double suction between bearing pumps and would like to verify that their vibration levels are within acceptable limits. How should this be done, and what is an...

Q. I have been told that centrifugal pump impellers may still cavitate when operating with NPSH Available greater than NPSH Required. Is this true? If so, why do pump suppliers show NPSHR values when...

Q. When purchasing rotodynamic (centrifugal or vertical) pumps, how can we estimate if the efficiency of the proposed design is the best to be expected for our application?A. The Hydraulic Institute...

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...