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Quality Inspection Uncovers Impending Short-Term Failure

Often, a simple shortcut or misstep in a pump maintenance procedure or rebuild can lead to unforeseen and excessive life cycle costs, or ultimately catastrophic failure.

1. A tension test can verify 100% perpendicularity and parallelism of components.

When an end-user could not rotate its critical boiler feed pump shaft to align the pump to its driver, a combined cycle plant contacted an aftermarket pump service provider to examine a problematic third-party pump rebuild, as well as remove, inspect, and repair the failing equipment.

Prior to disassembling the recently rebuilt pump, the aftermarket pump service provider performed a visual inspection to see if there was any evidence of incorrect assembly procedures. The most apparent defect was observed on the outboard side of the pump. The shaft sleeve should have .250” minimum clearance between its face and the labyrinth seal, but the sleeve had been rammed into the lab seal making the pump shaft impossible to turn.

Before shipping any rebuilt pump, it’s essential to perform a quality assurance check to confirm the shaft turns freely. However, in this case, a few critical steps may have been overlooked during the pump’s previous maintenance work.

Read the full article in the May/June 2022 World Pumps Magazine.

 

Analysis & Engineering Upgrades Solve Ring Section Pump Failure

A major power plant in the United States experienced high vibration and recirculation issues with several ring section (BB4) boiler feed pumps, resulting in multiple catastrophic failures and unplanned outages. This case study details one of the pumps that was shipped to an aftermarket pump service center for a full analysis, troubleshooting, repair plan, rebuild and performance testing.

In combined-cycle plants, the demand for robust, yet expensive, barrel pumps diminished as the industry moved toward less expensive segmental rings pumps. Due to the recent shifts in the power industry, operators often face a shorter mean time between repair (MTBR), internal wear and high vibration issues on newly installed units.

After experiencing numerous boiler feed pump performance and reliability issues at their power plant, the plant owner opted to pursue a comprehensive root cause analysis and repair plan with an aftermarket pump service center in Los Angeles, California. The investigation ultimately revealed a series of underlying issues linked to the performance problems and unexpected pump failures.

Video: https://vimeo.com/452266877

Source: https://www.pumpsandsystems.com/analysis-engineering-upgrades-solve-ring-section-pump-failure