Bearings

Latest Bearings Articles

Minimizing pump downtime directly affects the bottom line. Sealless mag-drive and canned-motor pumps, commonplace in the petrochemical and power industries, enhance reliability and reduce emissions and leakage compared with more traditional sealed pumps. The choice between sealless and sealed pumps often involves savings in both time and money.

For any bearing used in rotating machinery, applying best maintenance practices and using the correct enabling tools can help contribute to maximum bearing service life. These practices include proper storage and mounting, adequate lubrication, and close monitoring and inspection that can uncover the root causes of any damage.

Many industries use variable frequency drives (VFDs) with induction motors. Introduced in the 1960s, VFD technology has advanced considerably during the past 50 years. The engineering advancements have encouraged operators to consider other factors during particular applications, such as harmonics, energy efficiency, temperature, rise time, cable length and switching length.

Despite their simplicity, centrifugal pumps often experience repeat failures that even seasoned maintenance and reliability professionals have trouble preventing. This four-part series explains the reasons behind repeat pump failures and uses a real-world field example involving boiler feedwater pumps.

Minimizing pump downtime directly affects the bottom line. Sealless mag-drive and canned-motor pumps, commonplace in the petrochemical and power industries, enhance reliability and reduce emissions and leakage compared with more traditional “sealed” pumps. The choice between sealless and sealed pumps often involves savings in both time and money.

A multistage BB5 diffuser machine in oil transfer service in the Middle East had been in operation for many years without problems. After a routine maintenance strip down and rebuild, the pump experienced a high thrust bearing temperature of 105 C, which caused it to alarm and shut down. The temperature range had previously been 75 C to 85 C.

Within the oil and gas industry, the rotating shafts of equipment—such as pumps, motors, compressors, gearboxes and turbines—perform an essential function in both upstream and downstream applications. This rotating equipment ensures process flow and the safety of employees and the surrounding community.

Few industries can tolerate the unscheduled downtime of critical equipment. In refinery operations, it can have particularly serious implications. For an operation that runs 24 hours per day year-round, the losses—in both production and profitability—can be staggering.

Active magnetic bearing (AMB) reliability and availability levels have surpassed oil bearings after 10 years of technological advancements. These advances have made an impact on the industry, drawing attention from major original equipment manufacturers globally.

Bearing currents occur in specific motor and drive installations and can lead to motor fatigue and failure. While no system is inherently immune to bearing currents, few installations experience bearing currents during normal operation. While many installations have preventive measures installed, knowing that protection is in place is sometimes outside the owner or operator’s scope.

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Columns

For those of you old enough to remember Lawrence Welk, you’ll notice that the title of this brief column is the final quote from his show’s closing song. I am still a loyal fan of his reruns today.

Despite its name, pump specific speed (NS) does not have much to do with the actual speed of a pump.

A reciprocating power pump, as depicted in Figure 1, is a displacement machine. It has characteristics that are different than a centrifugal pump.

Blogs

Today marks the final day of the 2015 International Water Summit (IWS), a gathering of water and sustainability experts from around the globe. Thousands gathered in Abu Dhabi this week to discover solutions to problems such as water scarcity and efficiency.

Previous “Pump System Improvement” columns covered the assessment of simple systems with a single load. The system discussed in this column has multiple loads. Figure 1 is a schematic of a piping system under evaluation.

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Upstream Pumping

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