Feed pumps are an essential piece of the steam cycle and their performance directly impacts the ability of the plant to produce power. As a complex component moving high-temperature, high-pressure fluid, maintaining critical fits and tolerances during construction and refurbishment is essential. It is equally important to ensure that field assembly and installation is performed with experience and precision.
Using experienced technical field advisors (TFAs) when performing field work is even more critical as equipment ages. During a typical lifetime, equipment will undergo multiple refurbishments that may change the dimensions of the internal element, casing, and discharge head. For BB5 pumps, commonly referred to within the industry as barrel pumps, the barrel usually remains installed in the system and is not sent out with the internal element and head for refurbishment. As the installation settles, foundation degrades, and components undergo repeated thermal expansion and contraction, this barrel can lose some of its dimensional integrity.
One of the greatest pitfalls in performing a successful field installation is blindly trusting the installation and operation manual (IOM) supplied with the equipment. While this document provides useful guidance, any component changes that have occurred, both intentional and unintentional, are not reflected here. It is also important not to presume that pumps running in parallel have identical barrels or that internal elements are interchangeable. Instead of falling victim to these assumptions, best practices include completing a field dimensional analysis.
The value of capturing and recording critical data was proven during a complex boiler feed pump project at a coal-fired power plant. This project also highlighted the importance of adaptability and being able to react quickly to changing circumstances when performing fieldwork.
Read the full case study in Pumps & Systems February 2025 digital edition.
Learn more about Hydro’s Field Service capabilities here.
Many of our aging facilities are still using the pumps that were purchased and commissioned during plant construction. Despite the age of this equipment, effective maintenance strategies and upgrade opportunities can extend useful life for decades more. Older pumps are often more robust than current designs, which take advantage of new manufacturing technologies to reduce the raw materials needed for construction. However, vintage equipment has its downfalls as well. It is important to understand the challenges we face when operating and maintaining vintage equipment so that we can stay ahead of potential sources for decreased reliability.
Industrial pumps are sometimes repaired or modified by smaller local repair shops that do not have the engineering oversight to ensure that the repairs and modifications meet the original design’s intent. When Hydro received this pump, it was clear that prior modifications that had been performed without engineering review were causing problems.
Hydro specifies machining and fit-up tolerances that often exceed the required industry standards and are best-in-class for the pump industry. Taking the extra time to meet more stringent tolerances ensures better concentricity and parallelism of critical components, reducing the risk of contact between the rotating and stationary elements during operation. Reducing component contact will result in reduced vibration and reduce the rate of wear for close clearance components. Maintaining design clearances greatly contributes to longer mean-time-between-repairs by providing greater stiffness and damping to the rotating assembly and reducing internal recirculation, which in turn affects performance and efficiency. To learn more about the importance of maintaining design clearances, 