Case Study- Solving Vibration Issues in Vertical Pumps

Vertical pumps are especially susceptible to minor conditions that can result in elevated vibration amplitudes. The vertically suspended design and long stationary element lengths often combine into natural frequencies that are near forcing frequencies, such as running speed or even sub-synchronous faults. The complexity of these issues makes it difficult to diagnose and resolve persistent vibration issues with the type of data that is routinely available to the end users.

In-depth field testing paired with computational analysis provides a clear path to both an accurate diagnosis and a solution that has a high likelihood of success. The effectiveness of this methodology was proven for a Gulf Coast midstream company who was experiencing high vibration with their vertical freshwater pumps. By applying advanced field diagnostics, the end user was able to understand the underlying causes of the vibration and evaluate possible solutions in a theoretical environment prior to implementing them in the field.

Read the full case study, published in the May 2025 edition of Pumps & Systems magazine, here.

Read more case studies on vibration analysis and the work completed by Hydro Reliability Services here.

Vibration Institute Annual Training Conference 2025

Join Hydro at the Vibration Institute Annual Training conference in Newport News, VA and learn about our field engineering branch, Hydro Reliability Services. By combining extensive vibration expertise, field experience, and advanced technologies, Hydro Reliability Services diagnoses complex vibration problems and provides effective solutions.

Navigating Resonance Challenges

A Case Study in Diagnostic Testing and Innovative Solutions

Some services are inherently difficult due to factors such as fluid quality or multiple disparate operating points.  These factors are an inherent part of the process and cannot be changed to improve reliability. Harsh applications can be a costly prospect, both in overhaul costs and in the time and labor required for frequent servicing. Many times we become caught in the perception that there is no improvement to be had for these services. A short mean-time-between-failures (MTBF) becomes routine and expected, and maintenance activities and parts procurement are built around this expectation.  

When equipment is sent out for refurbishment, the expectation is that mechanical and hydraulic performance upon reinstallation will be better than what was experienced in the worn condition. This assumption holds true in most cases; however, sometimes unexpected behavior can occur after a pump is remanufactured and reinstalled. While it is easy to jump to the conclusion that these performance changes were caused by errors made during the repair or installation of the equipment, sometimes the problem is more complex and related to latent weaknesses in the design that had lain dormant until refurbishment.

This scenario was experienced by a power utility in the Southeastern US when they ran into significant vibration increases after one of their boiler feed pumps was refurbished by a local repair shop. Concerned by the level of vibration, the utility reached out to Hydro South, who have extensive experience in this application and model. From there, Hydro Reliability Services was called on to collect data on the problematic equipment and use advanced modeling tools to understand the nature of the vibration. The field testing and analysis revealed that pump had been operating with a very small margin between a structural resonance and one of the pump forcing frequencies. Armed with this information, solutions were developed to increase this margin and return to stable operation.

Read the full case study in Pumps & Systems March 2024 edition.

Learn more about Hydro Reliability Services and how they support field testing, vibration troubleshooting, and advanced system studies.

Energy Savings Audits- Understanding your Savings Potential

Many pump users focus on efficiency ratings when purchasing new equipment, but a much greater source of wasted energy is found when looking at the overall system instead of limiting optimization to the pump design itself. It is rare that a system is operating with equipment that is optimized to deliver flow while operating close to its best efficiency point. More often, pumps are oversized for their systems and achieve the desired flow rate by throttling a valve. The friction added by this valve changes the system curve to achieve the design operating flow; this action is one of the greatest sources of wasted energy in a pump system. Continue reading