# Columns and Blogs

In my last column (Pumps & Systems, October 2014), I explained that a capacitor’s current is totally out of phase with that of a motor’s magnetizing current.

I received a lot of feedback on my column “How Much Energy Do Pipes Remove?” in the September issue of Pumps & Systems.

Who determines where pressure gauges are located in a pump system? How close to the pump should they be, and what happens if these rules are not followed?

I hope that my last column (Pumps & Systems, September 2014) provided a clearer definition of power factor and how it can be calculated.

In past “Pumping Prescriptions” columns this year, I have discussed the procedure of piping size selection when given the process flow requirement and how this affects the pump’s power consumption. In this column, two computer calculation tools will be detailed.

Power factor (PF) is an important component of an alternating current (AC) circuit, but understanding its actual effect can be difficult. Why is PF mysterious to many of us? It has to do with the way it is explained.

In my July 2014 column, I demonstrated that three-phase voltage variation can significantly affect several alternating current (AC) motor characteristics. If that variation is large, it can also reduce motor life.

When the pump selection process starts, the required flow of the is often the only known variable for an application. For example, a system must move 2,000 gallons per minute (gpm) from a holding tank to another tank or process.

In my June column on pump and motor testing, I said that three-phase voltage variation and unbalance can have a significant effect on motor insulation life. Voltage variation is defined as the difference between the motor nameplate voltage and the incoming source voltage.

One of the supposed advantages of centrifugal pumps when compared to positive displacement pumps is their ability to operate across a wide flow range.

My last two columns (Pumps & Systems, April and May 2014) explained how pump suction behavior depends on how suction pressure is redu

In last month’s column (Pumps & Systems, May 2014), the drawdown analysis portion of the pump and motor field test spreadsheet was reviewed.

As anyone in the Reliant Center could tell you, the oil and gas industry continues to grow. This year’s attendance of 108,300 broke an Offshore Technology Conference (OTC) record.

All pumps should be tested regularly, but wastewater pumps are at the top of the list because they are especially susceptible to changing system conditions.

The global water crisis claims 5,500 lives each day—more than war, natural disasters, AIDS or hunger. It is a problem but not an impossible one to solve.

First of Two Parts

Centrifugal pumps have many advantages compared with positive displacement pumps. They have the ability to run all over the curve.

The legendary innovator was responsible for the design of more than 40 patented products during his seven-decade career.

Today’s federal requirements dictate the minimum efficiency of an electric motor, but they do not have any impact on the efficiency of a centrifugal pump.