It’s important to size an electric motor properly. Doing so will produce a pumping unit that is more efficient and provides a longer service life. Failing to size the motor correctly will result in a pumping unit that demands more power than it should or one that produces repeated electric faults and may suffer from premature motor failure. A Basic Introduction to Pump Motors Electric motors are generally sized at predetermined intervals. What this means is that in most cases you will need to round up to the next available motor size when determining how large a motor to couple … Continue reading Pump motor selection

Years ago, making a pump selection meant sitting down with large printed catalogs and flipping through them until you reached a pump curve that fit a project’s hydraulic requirements. Today this process is made much easier through the use of electronic pump curve catalogs. One of the most well-known developers of electronic pump catalogs is Engineered Software and their pump selection software pump-flo. Another popular option for pump selection software is Intelliquip. All of the curves in this article were generated by Pump-Flo’s web-based pump selection software. What is a Pump Curve? A pump curve is a graphical representation of the performance … Continue reading Pump Curve Understanding

In a previous article, we discussed some common impeller and casing designs. This article will consider what happens when you put the two together. End-Suction Pumps End-Suction Pump from Wikimedia Commons The most common centrifugal pump design is the end-suction pump. This type of pump combines a volute casing with a variety of impeller designs. Most typically, a radial flow impeller would be used, but in certain specialty applications, Francis-vane or mixed-flow impellers may be used. End-suction pumps are used in a large range of applications. Standard end-suction pumps are commonly used in fire suppression, plumbing, HVAC, and municipal water … Continue reading Centrifugal Pump Designs

There are a few components that virtually every centrifugal pump has in common. These components include: An impeller A volute or diffuser style casing A shaft Shaft sleeves Bearings A sealing arrangement These parts can be subdivided into the wet end and … Continue reading Centrifugal Pump Structure

The centrifugal pump casing is the component of the pump that converts all of the velocity created by the rotating impeller into a controlled and stable flow and directs it out of the pump through the discharge point. The most common type of casing is called a volute and it looks similar to a snail shell. Image from A Brief Introduction to Centrifugal Pumps by Joe Evans, Ph.D The impeller is placed within the volute. However, as you may have noticed in the image above, the impeller is not typically centered in the volute. Instead, the impeller is positioned so … Continue reading Centrifugal Pump Casings

The impeller of a centrifugal pump is rotated rapidly to impart velocity to a pumped liquid. If you’ve never seen a pump impeller before, visualize a boat propeller. When a boat propeller is rotated it imparts velocity to the liquid around it. As the liquid moves, that velocity forces the propeller to move forward in the water. Now imagine what would happen if the boat were anchored in place, firmly enough to prevent the boat from moving. Next imagine that the velocity generated by the boat propeller were contained and controlled so that a stream of water was created that … Continue reading Centrifugal Pump Impellers