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PeakVue Plus – Bearing Friction

In this the third of three videos on PeakVue, James Sylvester shows that when the Emerson AMS 2140 is setup correctly, PeakVue Plus can detect issues with lubrication health, in this case, the bearing friction was off the scale! The asset in question is a critical plant fan on a variable speed drive with an operational speed of 1200rpm with 22224 EK Taper roller bearings installed.

Incorrect grease used

This short presentation shows how PeakVue Plus detected incorrect grease used by the contractor prior to any considerable bearing damage occurring. As part of the site maintenance annual shutdown the bearing caps were opened, the grease removed and it repacked with fresh grease. Watch as James explains how the PeakVue Plus technology helped confirm the root cause, (6 mins):
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PeakVue Introduction – Part II

In this the second of three videos on PeakVue, James Sylvester shows that when the Emerson AMS 2140 is setup correctly, PeakVue can pick up sub surface Hertzian cracks. In this example, James refers to a 110KW Motor on a variable speed drive for a plant critical pump.

Outer Race Defect Identified

On an asset assessment survey of a critical plant, a sub surface defect on a motor bearing was identified; this was very early detection and allowed time to plan in the bearing replacement as to not disrupt the production schedule. Watch James explain in layman’s terms how the PeakVue technology works and what sets it apart from the others (6 mins).
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30-second summary

  • Common misalignments are usual and can happen to machines in a variety of ways.
  • Left alone misalignment can reduce the longevity of bearings, shafts, seals, and even couplings.
  • Misalignment is the root cause of most machine breakdowns: bearing failures, and damaged seals, shafts, and couplings.
  • It is widely believed that 50% of machine failures are due to misalignment.
  • Treating the misalignment early on, whether by a soft-foot correction, dial indicator alterations or a full-fledged laser alignment, will help to prevent total machine failure.
  • The basic rule of thumb is, machines that are precision aligned will function for a longer period and costs less to run.

How does misalignment occur?

Common misalignments are the result of two rotating shafts not parallel to one another, either by a slightly offset or angled gap at the coupling. However, sometimes in most real-life situations it is both, which is called a compound misalignment. There are several causes for misalignment:

  • Pipe strain
  • Thermal expansion
  • Human error
  • Wear causing sheave to deform
  • Baseplate settles irregular to form a ‘soft-footing’
  • Inaccurate assembly of components, such as motors and pumps.

The primary point to remember is that any unsteady motion or movement to shaft centrelines that goes against the intended motion of the machine can cause bearing or couplings to be stressed, and the seals to undergo damage in need of immediate repair.

The Laser Alignment course is ideal if want to improve your knowledge of shaft alignment. This is one-or-two-day Onsite course. It includes a walk-through of the alignment benefits and methods, as well as hands-on exercises – your understanding and appreciation of shaft alignment will skyrocket!

Five types of common misalignment

1. Parallel misalignment

This occurs when two shafts (or sheaves) do not exist on a parallel plane—while their centrelines may be parallel to one another, the actual centreline is offset.

2. Horizontal angle misalignment

This occurs when the angle of one shaft is different to the angle of the other on a horizontal plane.

3. Vertical angle misalignment

This occurs when the angle of one shaft is different to the angle of the other on a vertical plane.

4. Horizontal angled and offset misalignment

This is a compound misalignment that occurs when one shaft is both offset and angled differently than the other shaft along a horizontal plane.

5. Vertical angled and offset misalignment

This is a compound misalignment that occurs when one shaft is both offset and angled differently than the other shaft along a vertical plane.

How best to recognise and detect common misalignment?

While it is important to understand the root causes of misalignment and the most basic forms in which it occurs, the most important thing to know is how to recognize misalignment before it reduces the life of bearings, seals, shafts and couplings. As mentioned, a properly precision aligned machine will run more effectively and last longer, therefore the detection of misalignment is often best ascribed as a form of preventative maintenance, rather than a reactive resolution.

The AMS 2140 Machinery Health Analyser coupled with the AMS 8240 sensALIGN laser fixtures makes for a powerful combo-package that can help rectify misalignment issues easily.

How to detect shaft speed using a SpeedVue laser

With that in mind, there are five primary methods used to detect common misalignment:

1. Misalignment detection technique: Thermography

Becoming increasingly popular for its ability to recognise misalignment easily in machines, especially in belt drive applications. A clear indication of misalignment is an increase in friction as the offset or angular shafts are likely pulling against one another ever so slightly more. This, in turn, increases the temperature of the machine at the problem area.

The job of thermal-imagery, then, is to measure these hot-spots and determine exactly where the problem is occurring or beginning to occur. Thermography is a secondary indicator as when there is an increase in temperature damage is being caused mechanically.

2. Misalignment detection technique: Vibration analysis

Vibration analysis is effective at assessing the micro-vibrations of a machine and noting when it approaches or exceeds acceptable parameters. These minute observations can be used proactively, just as thermography, to recognise an issue with misalignment and stop it before the bearings or belts wear down to catastrophic levels. As the variables of those micro-vibration increases can vary by degree and complexity, often a result of some things more than only misalignment, imbalance or looseness overtime, the analysis is conducted using Accelerometers and correct sampling for the expected failure mode predictor. An important aspect of vibration analysis is phase analysis used to diagnose and pinpoint the type of misalignment early on. All these tools of measure help the analyst to determine exactly what is causing the disruption or how to prevent it escalating.

3. Misalignment detection technique: Oil analysis

One of the more complicated measures to determine common misalignment, oil analysis is a process by which an analyst can measure misalignment through the general wear-and-tear on contaminants in oil of the machine. While specialists are often required to conduct a proper oil analysis, its results often are not as effective for preventative maintenance with misalignment.

4. Misalignment detection technique: Laser shaft analysis

Likely the most common of all forms of misalignment checks, laser shaft alignment systems can accurately calculate the degree to which a coupling may be offset and allows for an accurate measure of remedy to get it along an even plane. Precision Laser alignment results can be greatly affected by operator experience and training.

5. Misalignment detection technique: Motion Amplification

This is the easiest of user’s interfaces to visually diagnose misalignment and also to visually see the rout cause of the misalignment. You do not need to be experienced or an engineer to view a motion amplification video so see there is misalignment.

Recent example: Iris M™ with the new Tach Sync

Pump base problem visualised

Our experienced vibration analysts can help recognise and fix common misalignment for your machines.

How to correct common misalignments?

The good news is that the hardest part of misalignment is determining where it exists for how long it has existed. The solutions to misalignment vary from simple to complex. Often it can be replacing bearings, belts, or couplings and other times those pieces are in good enough shape that all that is needed is a ‘soft-footed’ correction or slight alignment correction. If a misalignment has gone on for too long unnoticed, it might be the reason that the machine is beyond repair. On the other hand, preventative maintenance and scheduled misalignment analysis can help to ensure machine’s longevity, improve energy efficiency, maximize output, and overall save money by mitigating problems before they move beyond repair.

Common misalignment issues are a topic on the Vibration Analysis CAT-II course. This is ideal for those who been performing vibration analysis for more than twelve months and have a good understanding of the fundamentals.

Gallery images

Precision Shaft Alignment is a learning topic within the iLearnReliability Condition Monitoring software. It is intended for anyone wanting to further their understanding of monitoring, diagnostics and precision maintenance to support increased plant reliability.

If you have any questions about common misalignment in maintenance and how Reliability Maintenance Solutions can help you, please feel free to contact us or leave a comment below.

FAQs on common misalignments

Of the different methods available, Laser alignment is the most accurate method. Laser alignment uses lasers to determine the exact shaft position but is very dependent on user experience in the process of precision alignment.

Measuring different sections along the horizontal and vertical planes will help determine shaft misalignment and whether the misalignment is angular, parallel, or often both. Phase analysis offers the most precises diagnose of misalignment.

When installing bearings be aware that common misalignment can often occur. Ensure that the housing is rigid to best ensure support for the bearing.


30-Second Summary

  • An infrared camera is one of the most primitive yet trusted methods for identifying an electrical connection or component problem.
  • Misalignment, steam/water leaks, bent shafts, and moisture are some of the issues that can be detected using thermographic analysis.
  • You can learn more about thermographic analysis by enrolling on a CAT I Vibration Analysis course.

Infrared Thermal Imaging is useful across many industrial sectors

Hi! I’m Craig Smith, a Reliability Engineer at RMS. Over the past few years I’ve been using Infrared Thermal Imaging technology to great affect, helping customers diagnose and repair maintenance issues with higher degrees of accuracy and speed.

This article is based on a planned electrical maintenance survey of panels and distribution boards looking for any irregularities. This consists of cables, cable connections, breakers, inverters and control boards.

Our Infrared Thermography service is a predictive maintenance inspection technique that is widely-recognized and an effective non-destructive (NDT) testing tool used often to check electrical and mechanical systems, buildings, roofs and facilities.

Traditional methods of detection

The traditional method for identifying an electrical connection or component problem is the use of an infrared camera when it is under load. However, there is misunderstanding about how to establish the condition of the connection once a thermal anomaly has been found.

Historical methods of Infrared Thermal Imaging have applied the use of temperature, or temperature rise, using the infrared camera, as an indicator of the defect severity. Infrared, however, only identifies surface temperature rather than internal interface temperature.

The value of Thermography is being able to identify that a thermal anomaly exists

While thermography can identify a connection problem through the thermal pattern, the connector surface temperature can be a poor indicator of the nature of the problem or its severity.

How do Thermal Imaging cameras work?

The A0404B1 Infrared Tachometer is recommended for indoor/outdoor use. When used with Emerson’s Machinery Health Analyzers, the phototachs provide a tach reference signal for applications that include measurement of turning speed, synchronous time averaging, machinery balancing, phase tracking, and coastdown/startup analysis.

Where can Infrared help technicians?

Now that we’ve briefly explained the importance of Infrared Thermal Imaging, let’s look at exactly how thermography helps in maintenance.

Key components that thermographic analysis can detect problems with include, but not limited to:

  • Misalignment
  • Bearing health
  • Steam/Water Leaks
  • Turbine machinery
  • Bent shafts
  • Solar panels
  • Moisture
  • Loose bolts, mounts, fasteners, etc.
  • Electrical issues
  • Process flow issues

Top tips when taking a thermal image

  • Understand the surrounding parameters:
    • shooting an image with sunlight or a reflective background (inside panels) will give you bad data
    • also if you are in a panel room and the AC is on
  • Stand at 45* to the object of interest and use multiple angles if possible
  • Adjusting the Emmissivity and Reflected temperature accordingly is a must, or you will get bad data
  • Using a known source of black body:
    • carry electricians’ tape with you and put a piece on the object if safe to do so
  • Don’t ignore small temperature differences:
    • if you are looking at two objects close together one may be quite a lot hotter than it appears on the image
  • Focus on the object and thermally tune the camera to suit using the temperature adjustment

Problem awareness

  • Connections problems occur when fitting lock screws that are under-torqued or Over-torqued
  • Incorrect cable sizing for breaker etc, wrong size lug connections or not lug at all
  • Cable insulation not cut back enough
  • Poor soldered joints.
  • Excessive vibration in the area,
  • Process patterns with stop start or VSD motors
  • Environment issues such as heat or steam, corrosives
  • Always have a good scope of the area you are working in and a good visual of what you are looking at

Recent images explained

The CAT I Vibration Analysis course includes a topic on Thermography. The course is designed for reliability engineers, PdM program managers, and other maintenance staff who would like to understand condition monitoring with a core focus on vibration analysis.

If you have any questions about the role of thermal imaging in maintenance and how Reliability Maintenance Solutions can help you, please feel free to contact us, or leave a comment below.

FAQs

Historical methods of Infrared Thermal Imaging have applied the use of temperature, or temperature rise, using the infrared camera, as an indicator of the defect severity. Infrared, however, only identifies surface temperature rather than internal interface temperature.

Key components that thermographic analysis can detect problems with include, but not limited to: Misalignment, Bearing health, Steam/Water Leaks, Turbine machinery, Bent shafts, Solar panels, Moisture, Loose bolts, mounts, fasteners, etc., Electrical issues, Process flow issues.

Don’t ignore small temperature differences. If you are looking at two objects close together one may be quite a lot hotter than it appears on the image.


30-Second Summary

  • Vibration analysis allows you to detect early signs of machine failure/deterioration. 
  • A trained vibration analyst can easily understand the basics of vibration analysis as well as the failure modes of the equipment.
  • Predictive maintenance helps in preplanning all maintenance tasks as well as any unavoidable downtime.
  • Vibration data acquired from reactive maintenance can help replace or repair the parts which are exhibiting signs of wear and tear.

Vibration Analysis in Maintenance

Can your technicians make the replace-or-repair decision?

If you engage in maintenance practices, you will want to ensure your technicians can make the replace-or-repair decision before complete system failure of key components takes place. The easiest way to manage this risk is with vibration analysis.

Vibration analysis allows you to detect early signs of machine failure/deterioration. This allows your technicians to replace or repair machinery before catastrophic system functional failure takes place. Read more


PeakVue Introduction – Part I

Here is a the first example from James Sylvester of how visually helpful the new Emerson 2140 PeakVue Plus is while working on site.

Poor bearing lubrication identified and immediately remedied

On a recent survey of a critical 110KW blower motor we noticed the PeakVue levels had increased. While at the machine we quickly ran the PeakVue plus and this highlighted the issue as a poor lubrication condition.

Instead of writing this in the report then living in hope the motor is correctly greased, we showed this at the machine to the site fitter and we were immediately permitted to lubricate the bearings and the levels reduced.

PeakVue Plus was great as we did not have to upload to the laptop to explain. We just showed them the colour chart indicating poor lubrication and they acted upon it there and then.

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Flue Gas Recycle Fan: Introduction

The Flue Gas Recycle Fan is part of the COGA unit. The fan increases the efficiency of the COGA unit by recycling a proportion of the incinerated gases from the COGA stack. The fan is critical in sustaining high rates of operation on the plant, catastrophic failure of this fan would result in a COGA unit shut down. This would increase the emissions to the atmosphere and heavy fines could be imposed by the Environment Agency. Read more


23RPM Defect on a 4 Point Contact Bearing

This was to be the final of the five case studies on Enhanced System Reliability by James Sylvester. But, following on from feedback we will have one more case study next week, this will be an extra long project case study!

In this fifth case study from his book “Enhancing System Reliability Through Vibration Technology”, James Sylvester from JPS Reliability and an Reliability Training Institute Trainer, demonstrates vibration analysis of a slow rotational 4 Point Contact Bearing, with a 23RPM Defect. This is to remind us that correct database set up, and Time Waveform Analysis is so important in slow rotational bearings. Read more


30-Second Summary

  • Understanding the machine, getting early warning of faults, detection of all fault conditions, and repeatable measurements are crucial for effective vibration analysis.
  • Vibration analyst courses that are compliant with courses that follow the ISO 18436 standard are quintessential in the present-day scenario.
  • An efficient vibration analyst must take quick and economical measurements, and aim to detect the most common faults before the failure of the machine.

ABSTRACT – Vibration Analyst Checklist

Practical advice is given on getting the most meaningful and the most accurate information from machine vibration analysis, viz. on identifying the appropriate measurement locations and axes, the optimal data collection settings and the best analysis techniques. Also stressed are the importance of good reporting practices and the desirability of root cause analysis and acceptance testing.

INTRODUCTION

Vibration analysis is a fantastic field. For the analyst it is challenging and stimulating, and it should be rewarding. For the employer, it offers great financial rewards. But the question is: are you taking full advantage of the potential of vibration analysis? On the face of it, it can seem pretty simple. If you follow the set-up recommendations of the data collector vendor, and make sure that you mount the sensor on the bearing, then you will capture a spectrum that looks about right. It will have peaks and patterns which make it look like the spectra you see in the case studies. So you must be doing it correctly, right?  Not necessarily. Read more


30-Second Summary

  • Vibration analysis can help detect bearing defects, but can’t do much to enhance plant reliability.
  • Detecting the root cause of the bearing defect is equally important when it comes to ensuring that the same problem doesn’t occur in the future.
  • RMS offers Online, Public, and Onsite ISO 18436-2 CAT I to CAT IV courses for vibration analysis.

Bearing Defects

Identifying bearing defects using vibration analysis is not going to improve plant reliability. To do this we have to look at the root cause of the defect and take action to prevent the same problem re-occurring in the future. 

Here is a nice example from a large ID Fan, after a 3 month shut down of the plant. The fan was restarted, straight away an outer race defect was picked up on the Fan NDE bearing by an RMS engineer. Read more