Latest Seals Articles

The phrase “It’s just a small leak” is rarely found in the vocabulary of any maintenance manager, pump operator or pipefitter.

A fact of life is that equipment operators spend more time with pumps than mechanics do. Leveraging this familiarity with equipment, operator-driven reliability (ODR) programs focus on maximizing plant reliability by enhancing the techniques operators use to monitor the equipment for which they are responsible.

The life of equipment, such as compressors or pumps, depends on the functionality of individual parts, including seals. As the useful life of a seal increases, so does the reliability and robustness of the pump. Premature seal failure is one of the reasons for growing maintenance costs and overall cost of ownership.

Rubber expansion joints are used in piping installations to compensate for thermal growth, relieve piping stress during operation, and reduce vibration and noise caused by rotating equipment. While a rubber expansion joint can compensate for pipeline misalignment, this compliant product has installation and operational limitations.

Cryogenic products are produced globally and are critical to industries such as refining, steel, medical, plastics, chemical, petrochemical, brewing, welding and fuels. Liquid nitrogen (LN2), liquid oxygen (LOX) and liquid argon (LAR) are some of the specific liquefied gases used in these products. During cryogenic production and distribution, operating conditions can be extreme.

Maintenance personnel usually dislike rotary seals. This is because replacing a low-cost oil seal requires dismantling a whole piece of equipment.

Pump manufacturing companies have made strides in improving design, efficiency and energy usage in recent years through developments in impeller profile and the use of optimized motors and variable frequency drives. All of these changes enhance end users' bottom lines by reducing energy costs.

In the U.S. and abroad, governments, regulators and third-party activist groups are considering policies and actions that could have implications for the sealing device industry. The passing of the Clean Air Act in the early 1990s was a watershed moment for the industry.

Dry containment seals provide enhanced safety and control of emissions. When coupled with the appropriate piping plans, they can provide early detection of sealing performance deterioration and trigger an alarm if the seal fails.

Climate has an often ignored impact on sealing systems. Damage from harsh weather conditions, such as intermittent storms or humidity, can be effectively managed. But daily exposure to the outdoors, especially where extreme temperatures are the norm, can wreak havoc on seals.


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.

Part 1 of this series (Pumps & Systems, March 2015) discussed what happens to a boiler feedwater (BFW) pump during plant transients.

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


In today’s high-volume pumping applications, energy efficiency and cost control are more important than ever.

Last month’s column explored the effects that oversizing a pump has on the motor driving the pump, the adverse results of a pump no longer operating at its best efficiency point (BEP) for extended periods of time and situations in which a design margin could increase cost of ownership.

Cahaba Media Group

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Upstream Pumping

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