Blog

Is it bearing information, number of poles, frame size, number of gears, impellers, blades, horse power, operating voltage, motor type, manufacturer, number of belts, sheave size, or tooth count? Nope! None of the above.

All of the above information is great to have when analyzing vibration data, but the single most important item that is always required is the running speed of the equipment.

Not knowing the true running speed makes vibration analysis impossible for determining the proper defect to be reported. For example, if the speed was recorded at 1,780 RPM, but the true speed was 3,560 RPM and a high peak at 3,560 RPM is present; it could lead the analyst to believe that the 2× turning peak is related to another issue. Having the proper running speed of the equipment will assist the analyst in making the correct diagnoses for the equipment.

Once the correct turning speed has been identified the spectrum can be broken into three types of energy: sub-synchronous, synchronous, and non-synchronous.

Having this information available can assist the analyst when analyzing the vibration data.

by Yolanda Lopez

MYTH: “Pipe Stress makes the alignment difficult.”

TRUTH: Pipe stress does not have any significant influence on the alignment unless you make corrections on the machine with the piping attached. In most alignment the corrections to eliminate misalignment are performed on one machine only, typically the one that is easier to move. In a pump-motor set the corrections are done on the motor. If there is sufficient room to shim and move, excellent alignment can be achieved regardless of how much pipe stress there is on the pump. Of course, pipe stress is undesirable and should be eliminated prior to the alignment.

Watch and learn more about Pipe Stress

by Yolanda Lopez

Are you adding grease to a bearing and not hearing any changes from your ultrasound equipment? If so, start wondering where the grease is going. It is a fact that if grease gets into a bearing the ultrasound decibel will either go down on a bearing that needs grease or go up on a bearing that is already over-lubricated.

Look for a blocked grease tube. Grease may be going into the windings on an electric motor. Do you see grease on the tube of the grease gun? Maybe a greaseable bearing was replaced with a sealed bearing at the motor shop after a repair. These are just some of the things you need to consider if you get no ultrasonic decibel change after injecting grease to a bearing.

Download 5-Step Acoustic Lubrication Procedure

by Yolanda Lopez

We often hear “Coupling alignment tolerances provided by the coupling manufacturer are good enough for shaft alignment.” or “There’s no need to align your machines tighter than the tolerances allowed by your flexible coupling.”

This is wrong because good quality flexible couplings may be built to withstand much more misalignment than what is good for your connected machines, in terms of the vibration and other forces created. Bearings and seals may wear out and fail faster than a highly misalignment-tolerant coupling. The reason for this “extra misalignment capacity” in flex couplings is that they may need to withstand significant positional changes resulting from thermal growth or dynamic load shifts. This lets you deliberately misalign machines to “cold alignment” targets.

Take a look at our Shaft Alignment Tools

by Yolanda Lopez

Every analyst develops their own process for analyzing vibration data. This is generally learned from others, being around to observe or communicate with, or from training the individual receives.  Often, the person collecting the data will be the same person that analyzes the data.  The process could include that during the data collection the person not only uses the vibration data collector but also collects physical data from their senses such as sound and smell to see what is going on with the equipment.  They ought to look for material under the coupling guard to see if an elastomer coupling is shedding pieces, which may indicate misalignment; look at the oil level if possible for signs of oil leakage; look at the mechanical seal area to identify other leakage.  Once data is collected one would generally look for anything outside of established alarm levels, look at the spectrum to see where the highest amplitude peak is at, look for other high amplitude peaks or groups of peaks and harmonic families, and look for sidebands around peaks to help in identifying source.  You would also look for the direction of the highest vibration. Examine the historical data too: you would want to look at the rate of change to determine how quickly failure is approaching. Also never, never forget to look at the time waveform as all data comes from the time waveform. I try to look at the time waveform in the raw units of the sensor as that can verify what you may be seeing in the spectral and give you a greater understanding of just how bad a problem you may be facing.

If you need a solution to help ease this process, consider our BETAVIB vibration analysis systems.

by Yolanda Lopez

When the breakdown/repair cycle becomes routine, you can bet money is being wasted. The psychology of manufacturing (if we can call it that) is very much overlooked.

Q: What if it was a personal affront to everyone in the plant, management, production and maintenance, for a machine to break down? Seriously. What if everyone viewed it as a personal failure when a machine failed unexpectedly? Do you think the necessary attention would be given to it? That might be revolutionary.

Of course, if too much time and effort is put into something, the cost will exceed the return, but if the necessary serious attention is given to an operating asset by EVERYONE, the next excellent idea that improves reliability could come from anyone.

“Ownership” is something we know to be beneficial in a manufacturing facility. We know that the more “personal” everyone feels toward the assets, the better they take care of them and the more creative they are about caring for them. When we feel that personal attachment of ownership, we are more forthcoming with our efforts and supportive of the efforts of others who share our valuation of the assets.

With this in mind I offer the following suggestion in order to tap into that inherent pride of ownership and personal attachment that many have to the company and assets of their occupation: LET EVERYONE SEE HOW UGLY IT IS!

Hang a sign on a machine that failed and shut your plant or process down. The sign should read,

This machine FAILED and shut our plant down:
Failed: August 30th 2011
Failed: May 4th 2015
Failed: January 19th 2017
Failed: August 11th 2018

And keep adding the dates. This way the bad actors become obvious to everyone, and even the MTBF will be obvious. The absence of a sign on a machine could then be as informative as the signs with dates.

If you can succeed in creating an ownership of reliability that cuts across department lines, the benefits could be enormous. Failures come from all directions: Operations, maintenance, engineering, management, procurement. Let everyone see the ugliness of it and encourage everyone to pull together to make it beautiful (or at least more attractive.)

by Yolanda Lopez

The diesel engine is the heart of heavy construction equipment and replacement costs are in the millions. Ingress of dust due to leaky air intake systems shreds components in short order.  The SDT TIGHTChecker quickly and easily pinpoints leaks in the air intake system.

Dust is no friend to a diesel engine. But when the integrity of the air breather and turbo charger is compromised by leaks, microscopic grains of silica and other contaminants are sucked inside. There, they wreak havoc on the engine’s internal components costing organizations millions of dollars in premature wear and downtime.

Worse yet, you may not even realize you have dust ingress unless you are conducting regular oil analysis. These leaks are nearly impossible to find using conventional methods. Visual inspection takes hours and is often unsuccessful. Production does not have the patience to wait. They need that asset back in the field, leaks or not.

But what if there was a way to identify those leaks in minutes, instead of hours? SDT Ultrasound Solutions teamed up with mining giant Rio Tinto in Labrador, Newfoundland to devise a simple procedure for identifying turbo leaks in the engines of their huge loaders.

Using SDT ultrasound technology, a transmitter is placed inside the air filter basket. The high frequency sound waves are contained inside the piping unless there is a leak. Any microscopic air gap in the pipe is instantly recognized by the handheld flex ultrasound detector.

An 8 hour inspection that often ended in frustration is now a worldwide success story that continues to save Iron Ore Company of Canada $8 million per year.

by Yolanda Lopez

Centrifugal pumps have a specific design point at which they operate most efficiently. This sweet spot is known as the BEP (Best Operating Point) which provides the design engineer with the required flow and pressure while also providing the best efficiency. If the pump has been specified incorrectly or is placed into a system which doesn’t have the proper system head, the pump will become a reliability problem child. When a centrifugal pump is placed into a system without the required system resistance, the pump will run off its curve to the right, resulting in early bearing and mechanical seal failures and impeller damage caused by cavitations. If the pump is placed into a system with excessive system resistance, or, as frequently happens, the pump discharge valve is throttled early, bearing and seal failures occur along with impeller problems caused by discharge recirculation. Best practice dictates that the pump be specified and designed to operate within +5% to –10 % of its designed BEP. This will result in lower operating and maintenance costs and a happy pump.

by Yolanda Lopez

Guest Tip by Bob Dunn from I&E Central, Inc.

In some environments, reflected sounds can make it difficult to locate a leak.  If you are in a confined area (a smaller room, or beneath/inside a machine), the leak can seem to be almost anywhere.  A good solution is to adjust the sensitivity downward.  Ultrasonic sounds will reflect, but lose energy each time they reflect.  By reducing sensitivity, the reflected sounds drop into the background, allowing you to locate the actual source of the leak.

Note that SDT inspection tools have separate adjustments for sensitivity and headphone volume, so you can manage sensitivity without affecting your ability to hear!

Download our Find-and-Fix Leaks with Airborne Ultrasound Infographic!

by Ana Maria Delgado, CRL

There are many different reasons to consider and implement an online vibration system. Some of the key reasons are:

  1. The equipment is critical to production.
  2. The equipment has a long repair time.
  3. The parts for the equipment have a long lead time.
  4. The equipment is not easy to access.
  5. The equipment is in a remote location.
  6. Equipment failure could endanger the environment or people.

Online systems like the CORTEX by BETAVIB allows not only vibration to be monitored but also many additional parameters (such as speed, temperature, pressure, and flow, to list just a few), all of which can also be monitored and recorded. In addition, a customized overview can also be created to allow anyone to quickly monitor the health of the equipment using red, yellow, and green alarms that will indicate if an issue is present.

The CORTEX Monitoring System (CMS) is a cost-effective, scalable solution, dedicated to the prediction of asset failure and the prevention of catastrophic failures and costly repairs. This innovative system will help you optimize your performance by monitoring the condition of your valuable assets with highly accurate diagnostic tools.

by Yolanda Lopez

Reposted from People and Processes, written by Jeff Shiver CMRP, CPMM, CRL

Do you find yourself wondering why your employees haven’t taken the initiative and approached you for additional training? Well, they must not want the extra training, right? Wrong! Sometimes, employees do want training, but they just don’t ask. Here’s why:

1THEY HAVE FEAR OF REJECTION
People don’t like to be told no! The majority of employees don’t understand the organization’s vision, goals, brand promise, or key initiatives.

2. THEY FEEL UNSUPPORTED
Employees get worn out from a culture of mediocrity being tolerated, commitments not honored, and requests being ignored.

3. THEY DON’T KNOW HOW TO ASK
Operators, Mechanics, Planners, and even Managers may not understand how to equate the returns of training.

4. THEY DON’T KNOW WHEN TO ASK
Many employees don’t know when there is flexibility within the budget.

5. THEY ARE AFRAID OF BEING NEEDY
If no one else is asking for training, then why should they expect to be treated differently?

6. THEY FEEL AWKWARD OR UNCOMFORTABLE
There must be a commitment for development and the line of communication should be open.

7. THEY DON’T FEEL CHALLENGED
They may be topped out and let with nowhere to go from a promotional perspective.

8. THEY DON’T KNOW WHAT THEY DON’T KNOW
When people have never been exposed to anything else, they don’t know what else is possible.

Keep these things in mind the next time you offer training, or feel that your employees should ask you if they want it. A better approach may be discussing this with your employees individually.

Check out LUDECA training offering for alignment, geometric measurements, vibration analysis, balancing and ultrasound.

by Ana Maria Delgado, CRL

Guest Post by Ricky Smith, CRL, CMRP, CMRT

Pipe stress is caused by misalignment of the mating surfaces of two pipe flanges creating abnormal internal stress of pump bearings, seals, motor bearings, couplings, and can possibly change the displacement of a pump.

General Rules which must be followed by maintenance personnel and contractors: (if you truly want to stop a long term pump problem)

  1. Pipe flanges attached to pumps must be aligned where the gap does not exceed the thickness of two gaskets or tolerance established by your company’s engineering standards.
  2. Pipe flange bolts must drop in without assistance.
  3. Cable pullers, come-a-longs, or long bars should not be used when aligning a flange which is connected to a pump.
  4. Validate the elimination of pipe stress by following the guidelines listed below.

Failure Modes experienced from Pipe Stress on Bearings:

  • Wear caused by seals leaking
  • Wear caused by static vibration
  • Indentations caused by overloading while static
  • Corrosion caused by inadequate lubrication caused by abnormal loading (seal leaking)
  • Flaking caused by misalignment and excessive loading

WARNING: Ensure your contractors follow the same process to eliminate pipe stress. Pipe stress elimination should be validated during commissioning of new pump.

Follow this process if you want to inspect your pumps which may have pipe stress:

  1. Align the two shafts between your pump and driver (typically an electric motor) to tolerance recommended by the equipment vendor or your company’s engineering standards.
  2. Validate misalignment to insure motor and pumps shafts are aligned to specification.
  3. Disconnect the outlet flange on the pump.
  4. Revalidate laser alignment of shafts.
  5. If alignment has moved then you have pipe stress. Do the same for the inlet flange.
  6. Make corrections as stated in the following procedures to eliminate pipe stress.

Elimination of Pipe Stress – “The Ricky Smith Method for Pipe Stress” as learned from Dan Turner (his maintenance and engineering manager at Exxon during his career in the 1970s)

  1. Bolt flanges to pump and insert blind flange gasket along with two regular flanges between pump and mating flanges (cover the hole between welding area and inside the pump).
  2. Attached welding ground to flange. (do not attach ground lead to pump; welding group must always be attached to flange) WARNING: Failure to accomplish this one task properly will cause bearing failure by “electric arcing” which is a failure mode of bearings.
  3. Tack weld flange into place reverse welding each tack.
  4. Allow to cool for 10 minutes.
  5. Reverse stitch weld on opposite sides on the flange similarly used for cast iron welding.
  6. After initial reverse stitch weld then weld normally using electrode recommended by the American Welding Society (typically E-6010 5P or GTAW)
  7. After root pass; weld in any direction you wish.
  8. Allow to cool and then disconnect flange, replace gaskets and;
    Validate bolts will drop into holes without pry bar.
    Validate gap between flanges is no more than two gaskets thick.

Learn more about the effects of running equipment with pipe stress, watch LUDECA Shaft Alignment Know-How Pipe Stress video.

by Yolanda Lopez

This blog post concerns rolling element bearings and not journal bearings.

When a rolling element bearing begins to deteriorate the damage usually manifests itself in one of the races (either inner or outer) followed by the rolling element, and finally the cage.  When the races begin to have defects these tend to excite the natural frequencies of the race which typically show up beyond the maximum frequency that most analyzers collect data to.

The specific defect frequencies are determined by the bearing geometry. One would normally start seeing peaks in the FFT spectrum in the 5× to 7× range and sideband peaks spaced at 1× rotational speed. As the defects progress, harmonics of the component defect frequency will move lower in the FFT with more harmonics showing, while the number and amplitude of the sidebands increases as well.

When you begin to see the defect frequencies of multiple components, then this indicates that the damage is progressing. In the time-waveform’s early stages you will see an increase in the amplitude of the peaks, indicating impacting; as damage increases the amplitude of the impacts will increase and for a time the pattern will resemble what is known as the “angle fish” pattern. This pattern will not last and may not even be seen depending on the frequency of the data collection. The pattern tends to go away because of continued deterioration of the bearing components.

by Yolanda Lopez

Question: When is it OK to over-lubricate your bearing?

Answer: NEVER!!!!, (almost) the exception is when high vibration exists.

If you attended the SDT/LUDECA Acoustic Lubrication Workshops then you now understand grease as a lubricating mechanism. You understand that the Churning Phase of the lubrication task is inevitable, and long-term, detrimental to the health of the grease. Therefore, we want to move as quickly as possible from the Churning Phase to the Bleeding Phase. This is the natural progression of precision lubrication.

Grease is not a robust grease mechanism. It is actually quite fragile compared to an oil only system. But we need grease as a lubricating mechanism in bearings because the properties of grease help to keep the lubrication in and around the warzone while sealing out contaminants.

Vibration is inherent in every machine system. Excessive vibration however, negatively impacts the ability of grease to lubricate. Some machine systems are intentionally vibrated as part of their function and process. Other equipment vibrated excessively because of a defect such as imbalance, misalignment, poor installation, or poor workmanship. For these machines, it might be best practices to over-grease their bearings.

I know that sounds counter to what we teach and know, but consider this. It is better to have thickener and oil in the warzone of the bearing, than it is to set up a bleeding mechanism and have the reservoir destroyed because of high vibration. If we let this happen we may never get any oil where it’s needed.

High vibration? Slightly over grease your bearing and allow a little thickener to exist in the warzone. It is the best compromise.

Download our 5-Step Acoustic Lubrication Procedure.

by Yolanda Lopez

Reposted from People and Processes, written by Jeff Shiver CMRP, CPMM, CRL

The CMRT exam is the leading credentialing program by the Society for Maintenance & Reliability Professionals (SMRP) for the knowledge, skills and abilities of maintenance and reliability technicians.

The CMRT exam tests competency and knowledge of specific tasks within 4 domains: Maintenance Practices, Preventative and Predictive Maintenance, Troubleshooting and Analysis, and Corrective Maintenance.

And that’s all well and good! But, why should you have your technicians certified? What are the benefits of having them pass the CMRT?

Here are 5 reasons why you should have your technicians certified:

  1. Validates the individual’s knowledge on maintenance and reliability best practices within the 4 domains.
  2. Confirms your commitment to advancing your team’s professional development.
  3. A globally recognized certification provides a personal level of satisfaction and pride of accomplishment.
  4. Encourages people to move beyond the status quo and achieve more for the organization.
  5. Determines strengths and opportunities by subject area to provide a development plan road-map.

Get certified today! Click here to learn more about the CMRT certification.

Learn about People and Processes’ Maintenance and Reliability Technician Core Concepts Course 

 

by Yolanda Lopez

Guest Post by Bob Dunn from I&E Central, Inc.

I had the opportunity use the Easy-Laser XT440 to assist a customer aligning a machine that had perpetually given them problems, with bearings always running hot. They had recently aligned the machine with dial indicators, but when we checked, it was off by .007, and this on a 3600 RPM motor. We removed their old shims and did a soft foot check indicating .032 under one of the feet. Further inspection showed an angular gap under one foot. It turns out that when new, someone had ground down the feet on the motor to better align to the pump – obviously not a precision job. We step-shimmed to fill the angular gap, then aligned the machine in a single move. Several of the techniques we used were unfamiliar to these mechanics.

Takeaways:

  1. Do your pre-alignment homework to detect and correct foundation issues.
  2. Be sure mechanics are really trained in alignment – not just how to push the buttons. By the way, Ludeca Inc. and I&E Central provide excellent training.
  3. The Easy-Laser XT-Series is a fast, accurate, and incredibly easy-to-use tool for coupling alignment and more. If you use something else, you should see what you are missing!

 

by Ana Maria Delgado, CRL

In most cases, when equipment is in failure mode, it begins to make sounds that are not commonly heard during normal operation conditions. Once this sound is heard a defect (at least one) is already present in the equipment.

Using our vibration tools can assist in detecting the defect before that sound is heard with the naked ear.

Think of a vibration sensor as a stethoscope that allows a vibration instrument to listen to the heartbeat of the equipment. The heartbeat is then recorded and data can be viewed historically for that equipment. The data can then be compared to other readings collected on the equipment to quickly see if any changes have occurred.

by Yolanda Lopez

There are 3 techniques that can facilitate your work in the field: the shielding technique, the covering technique and reflection management.

Shielding technique protects sensor from parasite ultrasound

1. Shielding technique

This technique greatly reduces the influence of interfering leaks. It consists in using a piece of cardboard or foam(*)… to create a barrier between the “parasitic” leak noise and the location where you want to detect/locate a leak.

(*) Any material will work. It will reflect approximately 90% of the energy coming from the interfering leak.

Practical advice: the precision indicator tip placed on the internal or flexible sensor acts as a shield. This technique is very useful when leaks are very close to one another.

Covering technique blocks a known leak from disturbing detection of other leaks in proximity

2. Covering technique

This technique also greatly reduces the influence of interfering leaks. It consists in:

Either covering an interfering leak with a rag or glove while you inspect an area.

Or covering the sensor with a rag or glove in the zone you want to inspect.

A leaking valve body can be conveniently covered with a cardboard carton too.

Ultrasound signal reflecting off a wall or hard surface can be tricky

3. Reflection management

When searching for leaks, we sometimes get the impression that a leak is coming from a place where there is clearly no compressed air, such as a wall or a partition. This is due to the phenomenon of reflection. Ultrasounds from the leak are bouncing off the reflective surface. You will find the leak by following the angle of reflection. The angle of reflection is equal to the leak’s angle of origin relative to the reflection surface.

Download SDT Leak Surveyors Handbook to learn more!

by Yolanda Lopez

As Published by Solutions Magazine March/April 2018 issue

by Ana Maria Delgado, CRL and Shon Isenhour, CMRP CAMA CCMP, Founding Partner at Eruditio LLC

During the many root cause analysis (RCA) investigations we facilitate and coach, we notice some themes that continue to manifest themselves in the findings. Often, they are grouped under the heading of precision maintenance or lack thereof. Let’s take a look at some of them and determine if they are also killing your reliability.

The six killers are grouped into three areas: Lubrication, Misalignment and Undiagnosed Wear.

Click here to read the full article.

by Ana Maria Delgado, CRL

Guest post by John Lambert at Benchmark PDM
Recently I have been seeing the P to F interval curve popping up a lot on my LinkedIn feed and in articles that I have read. It was a concept that I was first introduced to when I was implementing Reliability Centered Maintenance into the Engineering and Maintenance department at the plant where I worked at the time. It was a great idea, that if done correctly is maintenance benefit. Why, because its cost savings and cost avoidance. Let me explain this.

Fig 1. The P to F Interval Curve.

The P to F curve was used as a learning tool for Condition Based Maintenance. The curve is the life expectancy of a machine, an asset. The P is the point when a change in the condition of the machine is detected. The F is when it reaches functional failure. This means that it is not doing the job it was designed to do. For example, if it were a seal that is designed to keep fluids in and contamination out and is now leaking, its in a state of functional failure. Will this put the machine down? Probably not, but it depends on the importance of the seal and the application. This is an important point because the P (potential failure) is a fixed point when you detect the change in condition but the F (failure) is a moving point. Not all warnings of failure put the machine down very often you have options and time.
Consider this: If I have a bucket that has a hole in it, it is in a functional failure state. But can I still use it to bail out my sinking boat? You bet I can!
Failure comes at us in many ways and obviously we have many ways to combat it. If you detect the potential failure early enough (and it can be months and months before actual failure) it means that you can avoid the breakdown. You can schedule an outage to do a repair. It’s not a breakdown, the machine hasn’t stopped, it’s not downtime. This is cost avoidance and the plant can save on the interrupted loss of production because of downtime costs.
There are a lot of examples of cost avoidance and also of cost savings. For instance, at the plant I worked at we used ultrasound to monitor bearings. We detected a very early warning in the sound level and were able to grease the bearing and the sound level dropped. We saved the bearing of any damage, we saved a potential breakdown so this is cost savings. Even if there is some bearing damage, the fact that we are aware and monitoring the situation lets us avoid any secondary damage.
It’s one price to replace a seal and its more if you have to replace a bearing in a gearbox. However, it can be very expensive to have to replace a shaft because the bearing has sized onto it ruined it. Secondary, ancillary damage can mount up very quickly if you don’t heed the warning you are given with the P of potential failure.
This warning of potential failure gives you time before any breakdown. The earlier the detection, the more time. Time to plan, view your options. And what people tend not to do is failure analysis while the machine is still in service. A failure analysis gives you a great start on seeking out the root cause but start right away, not when the machine is down.
Condition monitoring or as its often called Condition based maintenance (CBM) does work. However, for me there is a down side to this and I will explain why shortly. CBM is based on measurement, which is good because we all know to control a process we must measure.

Fig 2. You may see the P to F curve compartmentalized like this one (see sections below). However, the whole curve is the life expectancy of the machine and we monitor it using Condition Based Maintenance techniques.

Consultants (and I’m guilty) like to put labels on things and you may see:
1.Design, Capability, Precision Maintenance.
2.CBM, Predictive Maintenance
3.Preventive Maintenance.
4.Run to Failure, Breakdown Maintenance.
For me the P to F interval curve starts when the machine starts. That means Design and Precision Maintenance is not in the curve and this happens before startup. A small point but it takes away from the interval meaning.
We use predictive maintenance technologies in CBM. Vibration, Ultrasonic, Infrared, Oil Analysis, NDT (i.e. pipe wall thickness) and Operational Performance. They are all very good technologies, yet it is a combination of cross-technologies that works best. As an example, vibration may give you the most information yet ultrasound may give you the earliest warning on a high-speed bearing. And then there is oil analysis which may be best for a low-speed gearbox. It all depends on the application you have which dictates what’s best for you. A lot of time and effort was placed on having the best CBM program and to buy the right technology.
This, I believe, lead to the maintenance departments putting the focus on Condition based maintenance!
This I think is wrong because we still have failure. This means that CBM is no better than Predictive Maintenance. This doesn’t mean that I don’t recommend CBM, I do. To me it’s a must have but it does not improve the maintenance process because you still have machine failure.
Machine failures fall into three categories Premature failure, Random failure and Age-related failure.
We want the latter of these. We know from studies that say that 11% of machine assets fail because of age-related issues. They grow old and wear out. This means that 89% fail because of some other fault. This is a good thing because it gives us an opportunity to do something about them.
These numbers come from a very famous study by Nowlan and Heap (Google it!) that was commissioned by the US Defense Department. It doesn’t mean these numbers are an exact refection for every industry but the study but it has stood the test of time and I believe it has lead to the development of Reliability Centered Maintenance. But let’s say its wrong and let us double the amount they say is age related (full machine life expectancy). That would make it 22% and 78% would be the amount of random failures. Even if we quadruple it its only 44% meaning random is at 56% and we are still on the wrong side of the equation. The maintenance goal has to be to get the full life expectancy for all their machine assets.
In order to get the full life expectancy for a machine unit I think you have to be assured of two things. One is the design of the unit which includes all related parts (not just the pump but the piping as well). The other is the installation.

Fig 3. The most important part of the life expectancy of a machine is the design and installation of the machine.

If you’re like me, and you believe that Condition Based Maintenance starts when the machine starts then you understand that there is a section of the machines life that happens before. You could make an argument that it starts when you buy it because, as we all know, how we store it can have an effect. However, what is important at this stage is the design and installation of the machine. In most cases, we do not design the pump, gearbox or compressor but we do size them so that they meet the required output (hopefully). We do quite often design the piping configuration or the bases for example. All of which is very important but the reality is that maintenance departments maintain already-in-place machine assets. So, although a new installation, requiring design work is not often done, installation is.
Remove and Refit is done constantly. And the installation is something that you can control. In fact, it’s the installation that has the largest influence on the machines life. The goal is to create a stress-free environment for the machine to run in. No pipe strain, no distorted bases, no thermal expansion, no misalignment, etc.
Precision Maintenance was a term I first heard thirty years ago. Its part of our M.A.A.D. training program (Measure, Analyse, Action and Documentation). It’s simple, it means working to a standard. Maintenance departments can set their own standards. However, all must agree on it and adhere to it. This is the only way to control the installation process. This is the way to stop random failure and get the full life expectancy for your machine assets. The issue is that we do not have a general machinery installation standard to work to. Yes, we can and use information from other specific industry sources such as the American Petroleum Institute (API) or the information from the OEM (both of these are guidelines) however nothing for the general industry as a whole. Well this is about to change. The American National Standard Institute (ANSI) has just approved a new standard which is about to be published. I know this because I worked on it and will be writing about it shortly.
If you look at the life cycle of a machine, we need to know and manage the failure as best we can. If we only focus or mainly focus on the failure, we will not improve the reliability of the machine. We cannot control the failure. What we can control is the installation and done correctly this will improve the process giving the optimum life for the machine.
I sell laser alignment systems as well a vibration instruments. If a customer were to buy a vibration monitoring tool before they bought a laser system. I would think their focus is on the effect of the issue not the cause. What do you think?

by Ana Maria Delgado, CRL

1 2 3 11