A Midwest power utility customer was experiencing increased vibration after a refurbished Condensate pump was reinstalled on-site. They reached out to Hydro Reliability Services to help troubleshoot the vibration issue and determine if it was a problem inherent to the equipment or the result of the refurbishment. Continue reading
Dr. Gary Dyson received his Ph.D. from Cranfield University and has spent his entire career specializing in rotating equipment. He has used his hydraulic expertise to help many customers re-engineer their equipment to improve reliability, performance, and efficiency.
Dr. Gary Dyson is now a regular columnist for the industry magazine, Pumps & Systems. In the past, he has written many articles for the magazine and now shares his wealth of knowledge on a regular basis.
To check out Dr. Dyson’s contribution to the magazine, click here.
For more information on how Hydro can reduce downtime and costs, visit us online here.
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.
A large American energy company wanted a new data collection system to be integrated into its site historian along with process trending software to better diagnose system-related issues that can lead to maintenance issues.
Thanks to the help of an aftermarket service company, the energy company combined multiple sources of data and can now view complex mechanical vibration phenomena in parallel with plant process data. By comparing the two sets of data side by side, plant personnel will correlate process conditions with mechanical vibration data.
The service provider’s history of pump and rotating equipment knowledge helped to provide actionable analysis of pumps and other rotating equipment health—and a mechanism to provide additional engineering solutions to complex problems. Combined with the energy company’s focus on reliability and a history of maintaining their equipment, this system provided an improved method of data collection and analysis.
Operating at low flow places the machine under a great amount of duress. It is always wise to have a mental picture of what is happening within the passages of the machine to understand why this is the case.
The days have long passed where pump vibrations were viewed as a matter of mechanical balance. Now, we recognize that even if the pump had perfect mechanical balance, it would still exhibit vibrations.
The intensity of this remnant vibration turns out to be flow related with its minimum level being at or around best efficiency point (BEP).