Increase your Plant Reliability
and Increase Profit with a Seasoned Analyst.
Do you have unplanned failures? –
How much is this costing the company per hour? – Do you have any repeat
failures that causes disruption to production? – Are you firefighting faults? –
Do you have any equipment that is vibrating heavily that you can’t reduce? –
How can you improve your current maintenance practices?
Many companies don’t have the
expertise of a Seasoned Analyst to help them increase Plant
Reliability via an effective Condition Monitoring Program. Attached is a PDF
that contains information that can assist you in this.
With over 30 years’ experience in
the fields of Vibration Analysis, Infrared Thermography, Condition Monitoring
and Maintenance Engineering I have put together a book that your Engineers and
Maintenance Team will find extremely useful. Having worked with many of the
Blue-Chip companies in the UK and Australia, I have collated my experiences to
help and support the Non-Seasoned Analyst.
My experience ranges from
Lubrication, Thermal Imaging, Vibration Analysis, Ultrasound, NDT, Maintenance
Planning, Maintenance Improvements, Project Management and Mechanical
Maintenance including on site Dynamic Balancing and Laser Alignment.
I can provide an integrated condition
monitoring support service that will manage and drive your maintenance tasks
through Health Based Maintenance. This will enable you to know the health of
your system, engineer out repeat defects and increase production uptime.
Please read the attached book flyer for more details of how we can help you and your team. If you require further information, please contact us
We have managed to secure discounted postage with the printing company direct, this update has the new reduced postage costs.
This technical reference book comprises of over 20 years’ experience in the fields of Vibration Analysis, Condition Monitoring and Reliability Engineering. It is written with the technical tradesperson in mind, interpreting Vibration principles into layman’s terms. It has taken 7 years to fine tune the book and I have been though three demo versions. This is the first published version.
All data is from real-life situations with over 20 case studies throughout the book. This is to be used as material to help support knowledge sharing, practical training and mentoring to enhance System Reliability though Vibration technology
publication comes as an A4 300 page Paper Back printed in full colour on 120gsm
Part 1: Introduction to Condition Based Maintenance
Chapter 1 – Condition Monitoring
Chapter 2 – Mechanics of Failure
Chapter 3 – Condition Monitoring Technologies
Part 2: Condition Monitoring Management Processes
Chapter 4 – Setting up and Reporting
Chapter 5 – Practical Application
Chapter 6 – ISO Standards
Part 3: Vibration Analysis Condition Monitoring Techniques
A profitable plant is reliable, safe and a cost-effectively maintained plant.
The Seasoned Analyst
CBM Conference 2019 UK
I presented at my first Conference, and it was the first CBM Conference in the UK. It was well worth attending as I got to discuss various challenges in the condition monitoring and reliability sector, and the most common discussion point was buying from senior management and how to continually highlight the benefits of a condition monitoring program.
In addition there were vendors there demonstrating the latest advancements in condition motioning technology from vibration online and walk around, thermal imaging safety, ultrasound new high sampling rates time waveform analysis to motor electrical condition monitoring.
When all else fails, leave the air conditioning, and go examine the operating equipment. Go look, touch, feel, smell and listen to the machinery.
The seasoned Analyst
Online vibration monitoring is a great tool that enables monitoring of a vast number of assets, it helps the analyst when they “can’t see the woods for trees”.
This post is to highlight that for a full assessment of an asset you don’t just sit in your air conditioned office looking at the data on the screen. You must use other technologies and inspection tools to assess the Reliability of the system, the best tool is experienceand your human senses.
The SPM online system alarmed on a fan bearing. This fan has a direct drive AC motor to a fan lay shaft with two SKF/Cooper split bearings.
The onsite vibration analyst called for an inspection of the bearing due to mechanical/component looseness and an outer race defect. I was asked to confirm the diagnosis and provide further details.
On review of the data, and the new on demand live data, from the SPM system I concluded that the analyst was correct in the diagnosis of mechanical/component looseness and an outer race defect on the split bearing.
Figure 1 is
the SPM online Velocity spectrum from the 1st September, with low
overall one order and no harmonics.
Figure 2 is the SPM online Velocity spectrum on the 3rd September, and shows many running speed harmonics indicating a component/mechanical looseness.
Before I issued my comments I decided to “Leave the air conditioning, and go examine the operating equipment. Go look, touch, feel, smell and listen to the machinery”. Within seconds I spotted the issues and using my personal Motion Amplification tool, my finger! I felt and confirmed what my eyes were seeing.
Image 1 is of the drive end (Motor side) split bearing, all good.
Image 2 is of the fan NDE bearing (Fan side). The top cap retaining bolts were coming loose!
This was reported immediately to the on site maintenance team. Maintenance re-secured and torqued the bearing top cap bolts. It was found that both bolts were loose!
Post Vibration Analysis:
Figure 3 is the SPM online Velocity spectrum after the corrective actions, 3rd September. This shows a large reduction in the 1 order harmonics, confirming the loose bolts were the cause of the harmonics. It was also noticed that there were still some higher frequency data evident that was not there prior to the 3rd September.
analysis of the SPM HD Envelope spectrum displayed a clear defect signal for
the outer raceway. This is a split bearing so you would expect to see some
bearing signal but the fan end is a lot higher. This is not surprising giving
that the fan end bearing was in operation with a loose top bearing cap!
The data below compares the drive end (motor side) Figure 4 and non-drive end (fan side) Figure 5 SPM HD Envelope spectrum. This confirming that the fan end bearing signal is a lot higher.
This highlights that there is a place for an online monitoring system in some aplications.
In addition to preventing a catastrophic failure of the fan and this having a effect to the profitability of the site, this prevented what could have been a very dangerous safety incident with a fan coming loose at full speed.
For a full assessment of the system please leave
the air conditioning, and go examine the operating equipment. Go look, touch,
feel, smell and listen to the machinery. Don’t site and rely on one form of
data to make a decision that will affect the reliability and probability of the
A profitable plant is reliable, safe and a cost-effectively maintained plant.
A profitable plant is reliable, safe and a cost-effectively maintained plant.
I often am lucky enough to use different vibration technologies and this post is a great example of how a vibration analysis program can protect the business using the SPM HD Enveloping technique. This post is with thanks to assistance from Dean Whiteside.
As part of a routine vibration data collection program a change in condition was noted at the fan motor vibration levels. Vibration monitoring frequencies were increased to daily as the defect deteriorated. This enabled planning and a controlled change out of the motor.
On inspection of the vibration data, bearing outer raceway (BPFO) damage was diagnosed at the drive end motor bearing. This was clearly evident in the SPM HD Enveloping.
Figure 1 shows the Acceleration RMS trend from the motor drive end (DE) bearing location. This shows the steep increase in the impacting levels with an exponential increase in the final days of monitoring.
SPM HD Enveloping Data:
Figure 2 shows the SPM HD Envelope spectrum from the motor drive end bearing. This technique shows a clear impact at 3.09 Orders that matches the defect frequency for the bearing fitted. There are many harmonics indicating a very impactive signal.
Summary of vibration:
There is a clear distinct defect in bearing outer raceway, at these levels this would confirm a spalling to the raceway.
Due to the risk of failure, a new motor was sourced and placed on-site encase of instant catastrophic failure. The risks was discussed with production and was deemed too high to the process and a plan was put in place for a controlled stop. But prior to this date there was an unexpected line stop, and as the motor was all prepared on site, the motor was changed during this downtime.
Vibration data after controlled change-out:
Figure 3 are the SPM HD Enveloping spectra from before and after motor change out. The top plot showed the clear bearing damage and now with the replacement motor there are no bearing defect signals present.
Figure 4 is the Acceleration trend from the motor drive end bearing location. This trend shows the increasing and then the lowest record level with the new motor installed.
Bearing Inspection: After sectioning and cleaning
inspection, it was found as expected, a large visible defect in the loadzone of
the bearing outer raceway. Motor Drive End Bearing FAG 6316-C3
Image 1 is the drive end bearing sectioned.
Image 2 is the defect located in the loadzone of the outer raceway.
Notice the flat bottom of the spalled area and the “neat” cracks around it. These are cracks that have come to the surface and in time, more material will break away.
Image 3 is the defect located in the loadzone of the outer raceway.
Particle over roll as the bearing comes out of the load zone.
ISO 15243:2004: 5.1.2 Subsurface initiated fatigue. Primary causes of Subsurface initiated fatigue are repeated stress changes and material structural changes. This leads to microcracks under the surface, crack propagation and then spalling.
The bearing is damaged as soon as spalling occurs. Spalling gradually increases and gives rise to noise and vibration levels in the machine. This machine was stopped and repaired before the bearing collapsed. The period from initial spalling to failure depends on the type of machine and its operating conditions.
What is sub surface fatigue? In a rotating bearing, cyclic stress changes occur beneath the contact surfaces of the raceways and rolling elements. Consider the rotating inner ring of a radial bearing with a radial load acting on it. As the ring rotates, one particular point on the raceway enters the load zone and continues through an area to reach a maximum load (stress) before it exits the load zone.
During each revolution, as that one point on the raceway enters and exits the load zone, compressive and shear stresses occur. Depending on the load, temperature and the number of stress cycles over a period of time, there is a build-up of residual stresses that cause the material to change from a randomly oriented grain structure to fracture planes.
In these planes, so-called subsurface microcracks develop beneath the surface at the weakest location, around the zone of maximum shear stress, typically at a depth of 0,1 to 0,5 mm. The depth depends on the load, material, cleanliness, temperature and the microstructure of the steel. The crack finally propagates to the surface and spalling occurs.
This is another example of how vibration technology
and knowing system health and risk of failure enables data driven decisions to
benefit the business. The motor was replaced when the line was down due to an
unplanned shutdown, with no additional downtime occurred.
If this motor had failed without any planning this would have lost product and reduced profit. In addition these actions have protected the customers, supply chain and brand our reputation.
Apologies for the lack of posts, work and life has been busy but fun, now back to my hobby.
Whilst going though some of my files I found a spreadsheet I wrote first back in 2012/2013 (ish). I thought it would be a good spreadsheet to share.
The reason I created this spreadsheet was that in my job at the time I had to create Vibration Standards for database creation/standardisation across multiple business units and locations, and so I needed a quick way to decide upon the best data collection parameters that would resolve the defect of interest. There was also limited server space so I didn’t want to collect unnecessary data. Obviously, now with the advance in technology you can take one large data set with huge number of samples and a high sample rate.
The spreadsheet is self explanatory and has notes on each section to explain, please read the ‘Introduction’ tab first. Even though it was designed for the CSI Emerson MHM the ‘Vibration Calculator’ tab is universal (other than the Special time waveform option) whereas the ‘PeakVue Calculator’ tab is unique to CSI MHM.
This interactive calculator is good to help understand how the sample rate and number of samples affects the frequency and time domain resolution for what you want to resolve.
Apologies in advance on any terminology errors as I wrote this in the English/Aussie tongue, therefore there may be some miss interpretation from my English/Aussie to other cultures.
Click on the link below and have fun 🙂 and feel free to share.
This blog is to remind everyone that ‘this is the way we have allays done it’ doesn’t wash and also how important using the correct lubrication and lubricant cleanliness is!
This share has two questions;
What the highest Acceleration levels you have recorded on a fan rotating at around 1498 RPM?
Which bearing do you put as the fixed bearing on a fan shaft?
I appreciate the Accelerometer was only technically good for 50g’s but we had a reading of 116.28g’s Peak to Peak. Can you beat that?
requested to inspect a fan due to repeat failures of the fan bearings.
This fan process cold air, it is direct driven at 1498RPM and has two 22222 straight bore double row spherical roller bearings.
The fan NDE (Non-drive end / fan end) bearing was set as the fixed located bearing. The DE bearing at the coupling was set as the float bearing.
This fan had
been in operation for 17 days.
Data was collected with a 100mV/g Accelerometer with a flat rare earth magnet.
The vibration data indicated that the motor to fan shaft alignment was good and there were no issues with the Velocity imbalance levels.
There was however extremely high Acceleration levels indicating excessive damage to the outer raceway together with an indication of poor lubricant condition.
Vibration Acceleration Data:
Figure 1 is the Acceleration Time Waveform from the Fan NDE (Fan end bearing). This shows the very high impacting levels with a -52.59g’s peak to +63.69g’s peak.
Figure 2 is the Autocorrelation of the Acceleration Time Waveform. This shows that all this activity is being generated mostly from the bearing outer raceway.
Figure 3 is the Acceleration Spectrum. This again shows that all this activity is being generated from the bearing outer raceway.
Vibration PeakVue Data:
Figure 4 is the PeakVue Acceleration Time waveform. This shows very high general impacting up to 34.9g’s Peak.
Figure 5 is
the Autocorrelation of the PeakVue Time Waveform. This shows that all this activity
is being generated from the bearing outer raceway.
Figure 6 is
the PeakVue Spectrum. This shows that all this activity is being generated from
the bearing outer raceway.
Figure 7 is the Velocity Spectrum. This confirms that this is a late stage defect and that this energy is from the bearing outer raceway.
On visual inspection it was found as expected the grease looked oxidised in a poor state and there was a high area of damage to the bearing outer raceway – noticeably on one side of the rollers. Damage to this side of the raceway would have been caused by axial thrust from the fan shaft and motor.
Image 8: This
is on removal of the bearing caps. This shows the oxidised poor condition lubricant.
Images 9 to
12: These are further images of the grease condition.
Image 13: This shows the two tracks for the rolling elements on the outer raceway, and that it was highly loaded to one side.
and 15: These are close-ups of the defected area.
Summary and Questions:
the lubricant used we know this is not suitable for this application and that
it will displace/separate and then oxidise.
But the question is what caused the high thrusting to the one side of the raceway, is it related to what is the fixed and free bearing? Is it true to say that due to the NDE (fan end) being the fixed bearing that expansion from the motor/ fan shaft would load up one side of the raceway?
A profitable plant is reliable, safe and a cost-effectively maintained plant