Blower Outboard Bearing Failure Identified through Advanced Condition Monitoring


Maintaining the reliability and efficiency of critical equipment is paramount. This case study highlights the value of continuous, real-time condition monitoring by describing the how a premature failure was identified and resolved in a blower unit installed at a specialty materials manufacturer. The proactive implementation of Hydro’s Centaur condition monitoring played a pivotal role in early detection, enabling swift intervention and preventing unnecessary downtime.


A large US chemical plant that creates a variety of specialty materials had ongoing troubles with the centrifugal blowers in their PVC division. The units are critical to production and do not have spare backup units. Hydro’s Centaur condition monitoring solution was deployed on these blowers to understand the nature of the failures as well provide insight into when the units needed attention. One of the blower units began exhibiting concerning signs on January 04, 2024. Vibration levels steadily increased over the subsequent weeks, reaching a critical point on February 9th, 2024. This prompted the decision to shut down the unit and perform a root cause analysis to quickly determine remedial actions and keep production downtime to a minimum.

Events and Details:

When elevated vibration amplitudes were first detected on the problematic blower, they were in the Blower Outboard Bearing in the vertical direction (BOBV). The velocity amplitude shown below crossed the warning threshold on January 06, 2024, alerting both Hydro and the end user’s site engineers that a condition was present and in blower was in the early stages of degradation. The observation was discussed during the weekly touchpoint between Hydro and the plant, where Hydro would review the health of all monitored assets and address any alarm events captured using Centaur with site stakeholders.

Figure 1: Velocity Amplitude as Several Alarm Thresholds Breached

The vibration velocity amplitudes continued to climb, and on January 25, 2024 they crossed the Alarm #1 threshold. The Alarm #2 threshold was breached on February 01, 2024. Continual touchpoint meetings highlighted the worsening conditions and provided an analysis of the suspected failure mode(s) affecting the blower mechanical condition. The below multi-spectrum chart shows the spectra at the BOBV location at various points along the trend – mapping the signature of the degradation.

Figure 2: Multi-Spectrum Chart of BOBV Location

The chart starts with the spectra during “normal” conditions, prior to the observed degradation. Peaks at 1X and several harmonics are present with an amplitude less than 0.15 ips RMS. As the problem is observed and continues to worsen, bearing fault frequencies and harmonic excitation appear and continue to get worse. The lowest spectrum in the chart shows vibration velocity amplitude during the final sample, when it is greater than 1 ips RMS – very severe. At this point, all the energy has moved to 1X or less than 1X frequencies – a common occurrence when a failure mode is in its final stages.

The following two spectra charts take a closer look at the condition, one chart showing the initial conditions prior to degradation and the other closer to the end of operation where bearing fault frequencies and harmonic excitation can be detected.

Figure 3: Initial Conditions

Figure 4: Near End of Operation

In parallel with the velocity measurement, Hydro and the plant reliability engineers reviewed the acceleration measurements at the same location. Acceleration often leads to velocity readings, particularly for bearing failure. The chart below shows the trend for acceleration with the amplitude shown in g’s.

Figure 5: Acceleration Trend

The following four charts show the spectra and waveform data for acceleration readings at two points during the degradation period. The first two charts show the early stages of failure with peak-to-peak amplitudes of ~6 g’s and harmonic excitation in the spectrum. The second two show acceleration data at a later stage of degradation with peak-to-peak amplitudes at ~30 g’s and increased discrete frequency amplitudes in the spectrum.

Figure 6: Waveform- Early Stage of Failure

Figure 7: Spectrum- Early Stages of Failure

Figure 8: Waveform- Late Stages of Degradation

Figure 9: Spectrum- Late Stages of Degradation

The observation noted throughout was that the blower outboard bearing was failing. Failure of this bearing could also translate to damage to the shaft and other blower components if not addressed in a timely manner.

Constant communication between Hydro and the plant prevented the issue from becoming an unexpected and catastrophic failure.

Root Cause Analysis & Remediation:

The data captured by Centaur during the monitoring period was instrumental in conducting a thorough root cause analysis. It provided a comprehensive overview of the conditions leading to the outboard bearing failure, enabling Hydro’s engineers to identify contributing factors, such as operating conditions, lubrication issues, resonance frequencies, and potential misalignments.

The root cause of the issue was found to be contamination. This PVC unit created a fine dust byproduct that was found in the atmosphere, with large quantities accumulating around the blower units. Over time, the fine PVC dust would penetrate the bearings, compromising the effectiveness of the lubrication and reducing the tolerance inside of the bearings. Plans for remediation included relocating the machines or redesigning the bearing and housing to eliminate the possibility of contamination. The plant ultimately decided relocation was not an option and consulted the bearing manufacturer for an improved design that included a sealed housing.

Hydro continues to monitor these units, with ongoing reviews of the oil quality, level, and possibility of contamination from moisture, metal, or other sources. In parallel, Hydro also recommended reviewing the load handled by this blower and the rated load of the specified bearings, as improper loading may contribute to premature bearing failure.

Results: Cutting Edge Tech and Real-Time Support

Centaur proved to be the first line of defense in identifying abnormalities in the blower unit’s performance. Leveraging real-time data analytics, Centaur detected escalating vibration levels and issued timely alerts based on preset alarm thresholds. This early warning system allowed the maintenance team to take proactive measures, and consult with Hydro’s engineers on the data, receiving immediate real-time support thus preventing a catastrophic failure and minimizing the impact on overall operations. The ability to pinpoint the issue before complete failure occurred significantly reduced the downtime and associated costs.

This case underscores the value of proactive maintenance strategies for rotating equipment. With a strong focus on customer needs, experience across brands and applications, and a commitment to innovation, Hydro’s capabilities and culture uniquely aligned with the customer’s goals for improving asset reliability and performance.

Learn more about Centaur and how it can help you reduce the cost of rotating equipment ownership.

Capability Spotlight: Resolve Reliability Problems

Why look backwards when you can be looking forward?

The problems you inherited with your pump and system design shouldn’t be an anchor holding you back from stable operation. Hydro’s mission to increase pump reliability extends beyond our service facilities and into the field. Hydro Reliability Services provides expert troubleshooting, advanced engineering analysis, and field mechanical and hydraulic testing for your rotating equipment.

Many pump applications experience ongoing vibration and reliability issues; aging installations are also seeing margins between operation and resonant conditions eroding and previously reliable equipment being pulled into problems. The root cause of these problems is often resonance, a condition that is often misdiagnosed and commonly goes undiagnosed, resulting in persistent high amplitude vibration issues for long periods of time. Structural resonance typically results in highly directional vibration and increased amplitudes that can be difficult to resolve without the proper engineering approach. Fortunately, technology has developed to diagnose resonance and develop effective solutions without resorting to costly trial-and-error methods.

To help our customers solve complex problems with critical pumping equipment, Hydro Reliability Services’ engineers bring an array of technology to the site. Monitoring of traditional health indicators – flow, power, vibration, and pressure – is supplemented with advanced technology, such as Operating Deflection Shape and Experimental Modal Analysis. Leveraging their expertise and advanced modeling software, Hydro’s reliability engineers analyze this data to determine design and system weaknesses and propose improvements. This assessment gives you the ammunition you need to make an informed judgment about the risk of current and future operation.

Read our recent case study in Pumps & Systems magazine to learn more about how field testing and troubleshooting helped a power plant resolve a vibration issue in a critical application.

What does more effective troubleshooting mean for you?

  • Maintaining a competitive edge in your marketplace through reduced operation and maintenance costs
  • Creating a safer workplace with much lower risk of equipment-related accidents and reduced exposure to hazardous materials
  • Contribution towards a sustainable future through more efficient operation and reduced risk of product leakage into the environment
  • Ability to focus resources on proactive strategies and process innovation instead of continuously reacting to problem equipment

White Paper: Performance Prediction for the Aftermarket

Pumps are often expected to run at low flows and on many occasions can spend their entire operating lives there. It is important to understand the complex behavior of fluid and how that affects performance and reliability so that modifications can be made to achieve optimal performance in these challenging conditions.

By combining reverse engineered data, analytical tools and engineering expertise, a comprehensive approach can be developed to understand and modify hydraulic performance. This process allows pumping equipment to function exactly as required by the system that it fits within.

Download our latest white paper published with Pumps & Systems magazine to read Dr. Gary Dyson’s discussion of how low flow affects performance and what can be done to optimize operation and reliability.

Learn more about Hydro’s engineering services.

Webchat: Drowning in Data? Learn to Swim in the Digital Age

On June 4, 2024, Hydro’s Centaur team joined Chemical Processing for a webchat to talk about navigating the challenges of adopting new digital technologies.

The digital transformation presents both opportunities and challenges. As continuous monitoring becomes more ubiquitous, we are collecting exponentially greater amounts of data than ever before. At the same time, our industries are losing experience and facing reductions in manpower.

It’s natural to think that digital technologies could fill that gap, but many are realizing that without a thoughtful implementation strategy more data doesn’t always translate into greater reliability. During this webchat, we explored how to successfully implement condition monitoring technology to harness the power of data and drive effective decision making.

Some of the main discussion points included:

  • What are the first steps for a successful digital implementation strategy?
  • Quality vs quantity: How do we ensure that the data collected is meaningful and useful?
  • What resources are needed to analyze and act on information?

You can watch the full webchat here.

Chemical Processing Webchat with Hydro from Hydro, Inc. on Vimeo.

To learn more about Hydro’s Centaur condition monitoring, visit our Centaur webpage or contact us with questions.

We understand that hands-on experience is important in making an investment in a new technology, and provide end users with “test drives” of our monitoring solution through a commitment-free 90-day free trial. Interested in trying it out yourself? Apply here.

Capability Spotlight: Optimize Energy Efficiency

It’s estimated that 85% of pumps are not optimized to their systems, costing end users both efficiency and reliability. To achieve operational excellence and reduce environmental impact, assessing and improving our systems is essential.

Many OEMs focus on the initial pump design and providing a higher peak efficiency. While this can provide energy savings, it misses some of the greatest gains available. With our history in developing solutions for the aftermarket, Hydro approaches energy efficiency differently. Our unique experience as a brand-agnostic company focused on end users’ existing installed equipment has provided us with insight into improving equipment performance by understanding how it operates as a part of the greater system. This has allowed us to provide significant energy savings for our partners, as shown in successful cases such as this case study published in World Pumps magazine.

Hydro’s Energy Edge program takes advantage of our in-house engineering, field testing, remanufacturing, and parts capabilities to provide an end-to-end solution to improve energy usage and reliability. The process starts with getting the necessary design and operation data to perform a comprehensive analysis of current performance and identify opportunities for improvement. Depending on the findings, solutions can range from system operations recommendations to hydraulic modifications to a completely redesigned drop-in replacement. By providing a custom solution instead of an off-the-shelf replacement, Hydro not only optimizes performance, but minimizes cost, lead time, and risk by ensuring that the solutions fits into the existing equipment footprint.

Some of the aspects of an energy optimization project may include:

  • Energy Savings Audit: Field performance testing provides a performance baseline and identifies areas where improvements can be made
  • System Analysis: Using system design experience and AFT Fathom hydraulic analysis software, Hydro’s engineers model and simulate fluid flow through the system to accurately predict system behavior and optimize performance.
  • Hydraulic Modification: Modification to existing hydraulic components or design of new components provides hydraulic performance optimized to meet system needs. Our hydraulic specialists use both design knowledge and CFD analysis to provide the best fit design for the application
  • Equipment Remanufacturing and Parts Supply: Modifications are implemented through Hydro’s service center network, ensuring oversight and communication with the engineering design team. New cast parts are provided by our Parts Solutions division, ensuring control over parts quality and lead time.
  • Performance Testing: Testing in our HI-certified performance test lab validates new hydraulics and provides a new certified performance curve. Post-modification field testing can also be performed to provide data on field performance.
  • Continuous Monitoring: Using Hydro’s Centaur condition monitoring solution, equipment mechanical performance can be continuously monitored to provide better insight into equipment health into the future.

Want to learn more about energy efficiency and pump performance? Watch Bob Jennings’ presentation on the subject during Empowering Pumps 2024 Maintenance and Reliability Summit or read our co-authored eBook with Plant Services magazine.