The use of online condition monitoring systems are well known for their application in large-scale environments with highly critical machinery, where failures can escalate quickly and lead to catastrophic consequences. This case study highlights a glycol pump used for chemical processing in a Port facility. The Eastway Safeguard® System detected increased vibrations due to flow issues, enabling multiple failures to be diagnosed and repaired before incurring high costs.  Since its installation in 2019, the Eastway Safeguard® System has detected various failures in a timely manner for this client, ensuring continuous and reliable operations. Table 1 at the end of this case study illustrates the substantial financial benefits of predictive maintenance. By saving maintenance time, avoiding operational downtime, and preventing costly equipment failures, the Port facility achieved significant cost savings of €42,000.

Case description

In January 2024, increases in both velocity (mm/s RMS) and acceleration (g’ RMS) vibration were detected across the glycol motor and pump test points. Refer to Figure 1 for the acceleration vibration trend at the pump drive end and Figure 2 for the velocity vibration trend at the pump drive end from September 2023 to April 2024. These figures illustrate a gradually increasing trend over time, allowing the maintenance team to plan the job in advance.

Figure 1. Acceleration (g’ RMS) trend from pump drive end test point from September 2023 to April 2024.

Figure 2. Velocity (mm/s RMS) trend from pump drive end test point from September 2023 to April 2024.

Analysis and Recommended Action

After detecting an increase in trends through the Eastway Safeguard® System, Eastway remote monitoring team conducted a thorough analysis of the motor and pump vibration data. This analysis included examining vibration FFT (Fast Fourier Transform) spectra and time waveform signatures. The findings revealed a notable increase in overall vibration levels, particularly in the low-frequency range. Indicators of mounting looseness were evident, such as dominant high 1xRPM frequency and its harmonics, as shown in Figure 3.

Figure 3: FFT Velocity (mm/s) spectrum from February 2024 showing a dominant 1xRPM and its harmonics.

Figure 4 below displays a time waveform at the pump drive end from February 2024 showing high random impacting patterns, characterized by irregular sharp spikes. These impacts suggested potential issues like loose bolts, mechanical looseness, or instability within the machine components. Based on the analysis, it was recommended to check the Glycol motor and pump for any evidence of mounting looseness, including bolts tightness.

Figure 4: Time waveform from pump non-drive end.

Action Taken

As recommended by Eastway, the glycol pump was inspected. During the inspection, loose bolts and an oil leak on the pump side were found. The oil seals were replaced, the oil was topped up, and the bolts were tightened. As a result of these actions, vibration values decreased to normal levels, and the machine’s condition is now satisfactory, refer to Figure 5.

Figure 5. Velocity (mm/s RMS) trend from pump drive end test point from December 2023 to May 2024.

Figure 6 displays an acceleration (g’ RMS) FFT waterfall spectra comparison at the pump drive end test point from January 2024 (before maintenance) and May 2024 (after maintenance). It can be observed that 1xRPM settled down after the maintenance work was completed.

Figure 6. Acceleration (g’ RMS) FFT waterfall spectra comparison at the pump drive end test point from January 2024 (grey rear trend) and May 2024 (blue front trend).

Additionally, site personnel identified the root cause of the problem: flow issues related to operational parameters were causing high vibration in the machine. These operational parameters were subsequently adjusted to mitigate the risk of future occurrences.

Table 1. Estimated cost savings

Next Online Condition Monitoring case study: Enhancing Operational Efficiency By Identifying Deterioration In A Critical Centrifugal Pump