The "Cavitation - A Largely Misunderstood Phenomenon" article is authored by Joe Evans, Ph.D, Western Regional Manager for the Hydromatic Engineered Products division of Pentair Water. Below is a brief synopsis of the article. To read the complete PDF article click here.

“The goal of this tutorial is to help you gain a intuitive understanding of the cavitation process and its causes. I will leave its prevention to the many articles that already exist. Since boiling is the precursor to cavitation, we begin by taking a look at some of the properties of water and their role in the cavitation process. We then put NPSH into perspective and review some of the dynamics of centrifugal pump operation that also directly affect the process. We conclude with a discussion of the different types of centrifugal pump cavitation and the conditions that can cause them to occur.”

The "Centrifugal Pump Efficiency - What, How, Why, When ?" article is authored by Joe Evans, Ph.D, Western Regional Manager for the Hydromatic Engineered Products division of Pentair Water. Below is a brief synopsis of the article. To read the complete PDF article click here.

“In this tutorial, we will investigate several aspects of centrifugal pump efficiency. First I will define efficiency and give some examples. Next we will examine some of the design criteria that ultimately dictate the efficiency exhibited by a particular pump. We will also try to make that somewhat nebulas quantity, known as specific speed, more meaningful. I will also show its effect on the shape of a pump’s performance and power curves. Finally, we will discuss the importance of (or, sometimes, unimportance) of efficiency as it relates to a particular application or process. We will also illustrate the relationship of efficiency, head, and flow as they apply to both steep and flat performance curves and their roles in constant and variable speed applications. We will end with a brief look at the combined efficiency of a pump and its driver.”

The "AIR VS OIL FILLED SEWAGE PUMP MOTORS" article is authored by Joe Evans, Ph.D, Western Regional Manager for the Hydromatic Engineered Products division of Pentair Water. Below is a brief synopsis of the article. To read the complete PDF article click here.

“Some manufacturers believe that filling a motor with oil is the only way to go while others think air to be a better solution (pun intended). This paper takes an honest look at these two popular submersible sewage pump motor designs and compares the advantages and disadvantages of each. Topics covered include motor efficiency, heat transfer, bearing lubrication, maintenance, and environmental concerns.”

Pump Center Archived Articles - Read archived pump and system articles previously featured in the Pump Center.