Bio Plant APW Diaphragm Pump Wear

Background

This case study is from a Bio pharmaceutical manufacturing plant located in Ireland, Europe. The Eastway Safeguard® online monitoring system was installed on the critical assets, including this vaccum pump, on their APW Production line in 2017. Vibration sensor selection and positioning was carefully considered during the scoping of the project.

The Eastway team support the on-site maintenance personnel in this plant both on-site and remotely. Eastway provide monthly vibration analysis surveys in conjunction with supporting them 24/7 with automatic alerts, remote in-depth vibration analysis diagnosis and advice on the optimal maintenance decisions for their online assets. 

Case Description

In April 2019, initial increases in vibration were detected from the Drive End of this Diaphragm pump.

Machine Name ‘ABC’ Vacuum Pump Nest  
Description AC Motor Diaphragm Pump
kW 0.75kW
Motor Plate RPM 1410

The Acceleration and Velocity vibration warning alarm limits were breached, and automatic alerts were sent to key personnel and the Eastway team from the Eastway Safeguard® system. Analysis of the data was completed by the Eastway team and no action was recommended for the plant maintenance team at that time. Eastway would continue to Monitor for further signs of deterioration.

See Figure 1 for the Acceleration (g RMS) trend and see Figure 2 for the Velocity (mm/s RMS) trend for this period.

In June 2019, the vibration began to increase further gradually, again see Figures 1 and 2. It was recommended to confirm if any operational changes had occurred to the pump and to complete a non-intrusive visual inspection of the asset at this stage.

It was concluded by plant maintenance personnel that no changes had occurred in operation but a moderate increase in audible noise was noted from the pump when running.

Figure 1 DE Acceleration (g RMS) Trend 19 March 2019 to 20 Sept 2019

Figure 2 DE Velocity (mm/s RMS) Trend 19 March 2019 to 20 Sept 2019

Over the coming weeks the vibration levels began to increase further and in July 2019 higher level alarm limits were breached. Further online analysis was completed by the Eastway team, an example of this analysis was the interpretation of the vibration Fast Fourier Transform (FFT), demodulation enveloped spectra and time waveform signature. See Figure 3 for the Time waveform (g) signature and Figure 4 for the Acceleration FFT (g RMS) both from 16 July 2019 from this diaphragm pump.

Figure 3 DE Time Waveform (g) 26 Sept 2019

Figure 4 DE Acceleration (g RMS) FFT 08 Aug 2019

Recommendation:

Analysis of this continuous online vibration data by Eastway, determined early-stage wear in the motor bearings and internal wear in the diaphragm pump. It was recommended by Eastway to plan a maintenance intervention to correct these highlighted faults.

Action Taken:

As the first step, in July 2019 Motor bearings were replaced and new shock absorbers were fitted to the mounting frame. And in Aug 2019 the diaphragm pump was replaced.

Following this maintenance work, the vibration trends reduced and have remained satisfactory since these works were completed, with no further intervention required. See Figure 5 for the Acceleration (g RMS) trend from the DE from before the fault occurred in Mar 2019 to post maintenance in Sept 2020.

The previous evidence of internal wear within the diaphragm pump has also reduced significantly in the vibration signal, see Figure 6 for a Waterfall Acceleration (g RMS) comparison from 08 Aug 2019 and 17 Mar 2021 (18 months post maintenance). And see Figure 7 which demonstrates the Velocity FFT (mm/s RMS) from 17 March 2021 (18 months post maintenance) indicating continued optimal pump condition.

Figure 5 DE Acceleration Vibration Trend Mar 2019 to Sept 2020

Figure 6 DE Acceleration (g RMS) Waterfall Comparison of FFT’s from 08 Aug 2019 (Rear) and 17 Mar 2021 (Front)

Figure 7 DE Velocity FFT (18 months post maintenance) 17 Mar 2021

Results: Estimated* cost savings associated with avoidance of unplanned downtime, emergency repair costs & secondary damage:

Downtime avoided: 5 hours
Downtime cost per hour €20,000
Potential Batch Loss ++++
Total Savings: €100,000+++