Pumps & Systems Looks Back: Upgrading Utility & Process Pumps

Jul 18, 2023

Upgrade (up + grade, v.): to raise the grade of; to raise the quality of a manufactured product (Webster's Third New International Dictionary)

A pump upgrade (also called a revamp or retrofit) involves changing mechanical or hydraulic design or materials to solve a problem or increase reliable run time. An upgrade is different than a repair; an upgrade improves the design beyond the original.

Rerates are a type of hydraulic upgrade, usually involving a change in pump head capacity. Repowering may involve repairs and/or upgrades. Philosophically, repowering is different from normal pump maintenance because the plant being repowered has decided to spend capital monies to extend the plant's useful life.

Pump upgrade goals include:

To identify upgrade candidates, pump users should review maintenance records to see which pumps were responsible for a disproportionate share of expenses or cause safety or reliability concerns. Once identified, work with the upgrade supplier to evaluate upgrades available for your particular pump. Provide the supplier with a maintenance history so problem areas can be addressed.

The following are upgrade examples:

Mechanical design upgrades

Hydraulic design upgrades

The following are examples of upgrades to improve pump operation.

Boiler feed pumps are at the heart of most power plants, and economical plant operation depends on reliable pump operation. Many pumps from the utility building boom of the 1950s-1970s had larger capacities and more horsepower than previously supplied in order to meet increased plant size. As pump energy levels increased, so did the failure rate.

Progress has been made through pump manufacturers’ efforts to address first stage impeller design, materials and rotor dynamics. As a result, good reliability of high-energy feed pumps is attainable.

Some of the common upgrades for boiler feed pumps include:

Circulating water pump maintenance requirements vary greatly, depending on whether the pumps are used in freshwater or seawater.

For most freshwater applications, typical problems requiring pump maintenance are excessive vibration and premature bearing wear.

Circulating water pumps in seawater face additional problems due to corrosion. Material selection is critical, and the selection process must consider general corrosion as well as velocity effects, galvanic compatibility, and pitting resistance, plus manufacturability and cost.

Upgrades for circulating water pumps include:

Boiler circulating pumps (BCPs) are in a particularly sever duty, handling 600 F water at over 3,000 psig.

Many of the original pumps supplied in the 1950s and 1960s exhibited less-than-desirable life spans. In light of this, an upgrade program was developed that:

To date, more than 200 BCPs have been upgraded to this new design, and the resulting MTBF is typically two to three times that of the pumps before upgrading.

Process pumps may handle hazardous materials, and as a result seal leakage is critical. Industry standards (API 610 7th Edition), as well as federal legislation like the Clean Air Act, address mechanical seal reliability and pump maintenance.

There are upgrades available for process pumps to improve seal reliability and reduce emissions, including:

These descriptions cover some typical upgrades. This article focused on specific types of pumps, but upgrades are available for most models and sizes. Pump companies are useful resources for aid in problem solving. They are usually anxious to apply new technology and gain field experience with new designs and materials. Most upgrade suppliers can customize upgrades for individual users. Review your maintenance problems and discuss them with your pump supplier.

This bio appeared with the original 1993 article: Kurt Schumann is Manager of Pump Upgrades for the engineered Pump Group of the Ingersoll-Dresser Pump Company, located in Phillipsburg, NJ. He has 18 years of experience in design engineering and field service of utility and process pumps.