With the old mechanical displacers, level fluctuations ran 4-in to 5-in with a lot of hysteresis and frequent failures, causing operators to control at much higher levels than were optimal. New magnetic technology is changing all that. Here's how.

One of the major contributors to unbalance in rotating machinery is eccentricity. When we disassemble parts, we must also reassemble them. Even if the reassembly requires heating to shrink-fit the elements back together, we probably balanced them in a balancing machine where tolerances due to fit-up on mandrels or roundness of journals may possibly far exceed the heavy spot tolerances that the target standard of balance allows.

The DelMonte vegetable processing facility in Crystal City, Texas, is a cannery for spinach, carrots and beets. Located 40 miles from the Mexican border, the plant has been in operation since World War II. The facility's capacity for canned spinach currently approaches 800,000 cans per day, so it needs dependable equipment.

Few would dispute that variable frequency drives (VFDs) save energy, but the exact amount depends on the system. Hydraulically speaking, the main difference between a variable frequency (speed) drive and a discharge valve is that a VFD only changes a pump curve, while a valve only changes a system curve. A pump operates at the intersection between its H-Q curve and a system curve, and a change in either moves the operating point to a new intersection.

For controller-to-controller coordination, wireless Bluetooth is an excellent alternative to Class 3 radios.

Why is "run to fail" a common operational strategy at water/wastewater organizations? Explore this phenomenon and other results from a maintenance methodology survey.

Today's electricians are often found working in applications outside the realm of what is traditionally considered "electrical." Through new programs sponsored by the IBEW-JATC training schools and others, the skill sets of the electrical union workforce have broadened to include automation and controls.

Explore the current condition of SCADA reports and some new technology that will improve the quality of those reports.

Identifying the source of vibration by following the amplitude: the case of a company that thought the problem was a pump impeller, but, in fact, the problem was over 15-ft away and not a pump at all.

Dynamic pressure sensors and accelerometers are frequently used for precision measurements in oil, gas and petrochemical industries, as well as for natural gas supply monitoring applications. The development of piezoelectric sensor technology with integral charge amplifier, as well as the development of high temperature charge output designs, has been especially important for dynamic sensing applications. To truly understand the benefits of this technology, one must first review the evolution of this type of sensing.

Last month, we looked at adjustable frequency AC drive system, induction motor speed control and motor application and performance. This month we will explore specific operation conditions, applications and performance.

Wireless technology is part of our everyday lives in the home and office. From garage door openers and television remote controls, to cellular telephones and wireless Internet access, radio frequency (RF) technology has been accepted as a reliable, efficient and easy-to-use medium.

With the wide use of variable frequency drives in the pump industry and increasing unit size, it is becoming more difficult to design mechanical systems free from natural frequencies within operating speed range. If such an occurrence is allowed in the field, a resulting resonance condition threatens to significantly impact performance and longevity of the equipment.

Comparing the vibration performance of identical or like machines can be used to detect defects and judge their severity.

A crucial triumvirate for improving the bottom line. pump system optimization, pump efficiency

Last year in “Trending Revelations in Vibration Analysis,” (Pumps & Systems, June 2009), I discussed the importance of statistic trending in vibrations analysis. Usually, as most would expect, vibrations gradually increase with time. This increase reflects the normal internal wear, accumulative misalignment and deformations that can occur within a pump. All these wear conditions will lead to eventual failure.

Find out why level controls can fail in municipal wastewater treatment plants and similar systems and what technologies are available to combat failure.

Lift stations can be difficult and costly to monitor, especially when the stations are located in remote areas.

Since municipal codes frequently deal with the most crucial areas of public life-covering the safety of life and property-it is understandable that preference is given to tools and methods that are "tried and true" over ones that are untested. The challenge becomes how to take advantage of new advances in technology while recognizing the importance of maintaining an uncompromising level of safety and security. The answer can lie in close cooperation between officials who champion the integrity of the municipal code system and individuals experienced in the implementation of innovative technologies.

When it comes to pressure and flow, variable speed pumping applications can be divided into three basic categories. Constant pressure-variable flow (Cp-Vf) attempts to keep pressure relatively constant over a range of flows. Constant flow-variable pressure (Cf-Vp) tries to achieve the opposite by using varying pressure to keep flow constant. Variable pressure-variable flow (Vp-Vf) applications can accommodate a change in both.