Practical Problem:

Pipes vibrate and owing to such vibration the pipe fittings loosen and fluid leaks. For a process plant such leaks are substantial. So insight and understanding are needed to figure out as to how we might stop such unwarranted fluid leakage, which not only adds to the operating cost of the plant but also results in sudden breakdowns that affect productivity and profitability of a plant.

We start our investigation by revisiting he concept of Reynold's number in an effort to gain insights into the underlying phenomenon.

Revisiting Reynold's Number:

As we know Reynold's number may be described as the ratio of Inertia Forces/Viscous Forces.

We also know that for Reynold's number (Re) < 2000 the flow in a pipe carrying a fluid (liquid or gas) is laminar and all the fluid travels in a direction parallel to the pipe axis (being careful to neglect Brownian motion, which leads to a slight blurring of the streak lines of flow).This flow would normally create vibration in the pipe since the pipe selects the particular frequency of its choice (its natural frequency) from a range of frequencies imposed on it by the flow to naturally vibrate (high probability exists that the pipe finds its natural frequency from the range of frequencies imposed by flow of fluid). 

When Re > 2000 flow disturbances would probably grow, forming turbulent eddies, so that superimposed on the axial flow, there are circulating eddies of many sized with velocities up to about 1/10 of the axial velocity for a smooth pipe (assumption, which in reality might not be found). This is not very insignificant to cause additional vibration in the pipe, in all probability, perpendicular to the flow of the fluid. However, the effect of these turbulent eddies is to mix up the flow and to create a more uniform profile in the pipe. 

The importance of flow similarity is that, for two geometrically similar pipes, the flow behavior will be the same for equal values of Re in each pipe. For example, if we specify, therefore for calibration of a flowmeter, a certain value of Re and a certain pipe geometry, then we know, for sure, that this flow will be well defined.

For Laminar flow, Pressure drop is proportional to Velocity (v) and the resulting profile would be Parabolic.

For Turbulent flow, Pressure drop is proportional to square of Velocity (v) and the resulting profile would be flattened by turbulent mixing (higher entropy).

It is now Interesting to compare the similarity of the above two phenomena with the phenomenon of damping force experienced by objects moving in fluids. Where for low speed damping force is proportional to velocity and for high speeds damping force is proportional to the square of velocity. So, there is equivalent relationship between Pressure Drop and Damping Force. Hence we can conclude that higher the pressure drop (due to higher Re) higher would be the damping force that can significantly alter the vibration patterns of pipe vibrations.

The pressure drop or loss might then be referred to as the 'velocity head' that causes pipes to vibrate since absolutely ideal laminar flow is not found in practical applications. Hence turbulent flow exists as default mechanism of flow in pipes.

The pipes subjected to such vibrations (a combination of both low and high frequency vibrations) are stressed at their threaded joints, which automatically loosen up to allow fluid to leak past the open joints, 

Practical solutions:

1. Hangers that support the pipes might be placed in an axisymmetric manner thereby not allowing  the resultant vibration wave owing to fluid flow to travel by effectively breaking up the wave at its origin.

2. Increase the pipe schedule, if that is practically possible for the given conditions.

3. Change the fluid viscosity (generally increase), if practically possible.

4. Use longer length of threaded pipes (to increase the stiffness of the pipe joint).

5. Combine any of the above solutions in a manner found practical in the field.

Solution of a problem would depend to a great extent on the way we view or observe the problem and understand it.

For example, glucoma was defined as a 'pressure build up' behind the eye ball. So all treatments were geared towards relieving this pressure through cuts to allow the fluids that build up behind the eye to drain. But it did not yield great or desired results.

Only later it was understood that glucoma is a result of eating away of the optic nerve. Hence, two conditions were necessary to precipitate the problem -- Pressure + Optic nerve

With the change of view and understanding glucoman could be treated in a better way with more success.

The Approximate distribution of the inherent causes of machinery failures in Industrial Plants. 

70% to 90% of the failures --> latent design errors (usually systemic errors)

50% to 75% of the failures --> Operational errors

50% to 70% of the failures --> Maintenance errors

10% to 30% of the failures --> Abnormal environmental stress

1% to 5%   of the failures  --> Wear Out

Though these figures represent the distribution of causes of machinery failures, I suspect the same distribution holds true for any other system like Organizations.

Introduction
Condition Based Maintenance as the name implies is a tool and strategy to improve Maintenance. The basic philosophy is that we respond as per actual needs and not carry out activities as per a given plan or idea that forms in our heads. It does not depend on abstractions of any sort.

No doubt it is a fantastic concept.  I hesitate to call it a tool to solve our problems. What is the minimum it might achieve when used properly? It is known to reduce maintenance downtime by 50% (since we can plan the activity) and reduce surprise failures by 25% from a previous level of maintenance when CBM is not taken up as a strategy.

This is not a mean achievement. This is the minimum CBM can do. Properly utilized it has the potential to do much more. But as I look around I see industry after industry failing to achieve this minimum level of benefit.

Why does it not Work?

Naturally, it is time that we ask why?

First reason that comes to my mind is the level of difficulty to master the different techniques of CBM, which are becoming more complicated by the day. Whether there is a need for such complication is not known to me. But it takes time and effort to master the most valuable techniques we have and most industries aren’t quite willing to spare the time, effort and costs in order to achieve that mastery. The question is what do we master? Do we master the techniques or master the understanding of systems and design? Obviously, it must be both. Without a clear understanding of the laws by which machines and systems operate it is not possible to make any headway through the use of techniques. Mastering techniques is more of mastering information. There is lot of information. But information alone can’t help us. Bits of information must be stitched together to weave a story. Stories make meaning and such stories can only be told if systems are understood better. Unfortunately, machines do follow the laws of nature and the problem is we have till date understood a small and rather insignificant part of the inner working or Nature and its application to systems.

The second reason is improper understanding of the word ‘problem’. Most practitioners aim at finding problems. Is there something called a problem? Most fail to realize that the word problem is an ‘abstraction’ of the mind. It is rather funny that we even give names to different problems. We say mechanical problems, electrical problems, quality problems, operation problems etc. We don’t stop at that. Then we further classify the problems as bearing problems, coupling problem, unbalance problem, etc. That makes it pretty useless. Why? We are always looking at a part of the system and never the entire system as a whole. All problems are systemic. There is no such thing as a problem. The machine does not know of one. Nature does not know of one. How come we know of problems? And that is precisely the problem. And more we trying to qualify and define a problem more complicated it becomes, which itself becomes problematic.  

The third important reason is the application of the concept. To start with we buy some equipment. We then buy some software to go along with it. Have a list of ways we can detect possible problems. And lastly pick up some young boys & girls who have very little experience with machines and operations. Then we start with rotating machines. And then we tell that the objective is to find when a bearing would fail. It simply does not work. Why? This is simply because the ‘map is not the territory’. Having the infrastructure in the form of instruments, software, and people forms the ‘map’. The territory is improving Reliability of the system, Availability of the System and the Overall Performance of the System. Or in other words improving the system is the territory to be won. That is not what actually happens. The work design is grossly wrong leading to unacceptable results.

How Useful is it?

What happens when we correctly apply the deep conceptual understanding of CBM in a proper way? I would like to highlight three important cases from the real world. I would show you examples from process industries like steel, cement and chemical because in these industries the concept of ‘territory’ is vital for the survival of the industry. .

Case 1 – Chemical Industry

In a chemical factory, they were having 24 breakdowns a month. Obviously this was a pain. Pain was not only in trying to restore the system back but the pain was in loss of costly material and the time it took to restart the system. This was making them uncompetitive.

When they applied CBM in the proper way the results were amazing.

1. Breakdowns reduced from 24 failures a month to 1 (one) failure a year.
2. The annual consumption of spares reduced by 50%
3. Productivity improved by 30%
4. Profitability improved by 20%

Case 2 – Cement Industry

One of the well known Cement factories in India had a full fledged sophisticated CBM system in place. In addition, they were the first plant in India to have achieved the coveted Japanese TPM award.

But even after all these they were having around 57 breakdowns a year. After proper implementation of the CBM concept, the results were more than wonderful.

1. Number of breakdowns reduced to 1 in a year.
2. Longest kiln run hours in India
3. Maintenance costs reduced by 2/3
4. Profitability up by 15%

In fact they still win the international prize for the best overall maintenance performance amongst cement industries in the world. This is the 10th consecutive year they won the prize. That is not a mean achievement.

Case 3 – Steel Industry

In a Steel Industry their profitability was affected by the consistently poor performance of their equipment. The Availability stood at a maximum of 88%. Breakdowns were heavy and frequent. Their Yield was no better than 92%, 5% short of the best international standards. The Reliability was as poor as 33%.

After proper implementation the results were astounding.

1. Availability went up from 88% to 99%
2. Yield improved from 92% to 99.7% (presently the world standard)
3. Reliability went up from 33% to 96%
4. Profitability went up by 6%

The important thing is that they have been maintaining these standards for the last 6 years with the minimum of investment in CBM.

Conclusions:

1. Techniques & sophistication are secondary. The concept is primary.
2. Take time to learn the methods of knowing and reading reality.
3. There is no such thing as a problem
4. The map is not the territory.
5. Understand the ‘whole’ and not try to improve the system by parts.
6. Design the work system correctly to achieve the end.
7. To gain results invest in talent and less on techniques.
8. Solve all problems in one go to get ongoing benefits for years to come.
9. Learn from failures.
10. Induct people who learn from failures and have good idea of machines and systems.
11. Monitor what is going right not what is going wrong.
12. Aim at improving the Reliability Availability and Performance of the System to maximize your gains.

It is most interesting to find that the same concept of CBM can be applied to almost anything an organization does or any issue an organization is faced with.  The effectiveness of the concepts of other strategies for organizational improvement fade in comparison to the improvement concept embedded in CBM concept. Why? Because it is based on how Nature behaves not what we think the way it must behave. That is a natural advantage.

Should we go for it?

Ask that question to any vibration specialist worth his salt and he would immediately tell you that it is easy.

He might start something like this: "The frequencies tell us what the problems are and the corresponding amplitudes inform us how serious are the problems".

He would then fish out a chart that shows us what might be the possible faults at the various frequencies and another chart that might give some indication about the severity of the problem by indicating the possible amplitudes up to which the problem can be tolerated.

This is the easy way but often proves difficult to apply to understand vibration signatures. At one point or the other analysts do get into tremendous difficulties to make the right sense of the situation and find the right way to improve the system. Why is that? This is because there are no universal laws that might be applied to all vibration signatures. It is important to understand that all signatures reflect the general and the particulars. It means that every system and therefore every signature from a system is unique. Hence trying to make sense of a signature through some universal rules is bound to make things very difficult.

Is there any other way to get out of such difficulty?

Yes, the other way is based on the following premises:

1. The vibration signature shows a snap shot of the patterns the system generates. This pattern represents the present state of the system. Hence the frequencies and the amplitudes are all related to each other and have developed over time. Therefore it makes little sense to see or examine them in isolation.

2. What we are looking at are not looking at data (like frequencies and amplitudes) but observing movement and motion of the system. This is an important point that is often overlooked by analysts. The pattern would tell us about the movement of the system. From studying the movements we would understand why such movements are taking place and what is to be done to stabilize or improve the system.

3. Such movement might be noticed in 3 distinct ways. This is because essentially three types of movements are taking place simultaneously. They arise and abate simultaneously. These are -- the slow cycles (characterized by the low frequencies), the cycles that move at a medium speed (understood by the medium frequencies) and the cycles of movement that are quite fast, where changes take place quickly (reflected by the high frequencies).

4. The slow movement determines and affects the movement of the other two movements, namely the medium and the rapid. This slow movement is generated by the rotation of the machine/system. Hence such a frequency is always known as the 'fundamental frequency'. 

5. Now comes the crucial law -- Interdependence and the Principle of Opposites. Any movement is only possible if there are two opposing forces or aspects. One is always trying to win over the other or their interaction would produce an in-between state. Such opposition or contradiction of the opposites not only produces the movement or breakdown but also affects the medium and fast movements. This is the way they are all related.

Let us take an example to illustrate the principle. For our purpose we take a fan, say a ID fan. As the blades rotate two forces immediately come into play -- the force that makes the blades move (the primary motive force) and the wind resistance that opposes it (called the aerodynamic force). So long the primary motive force is stronger or greater than the aerodynamic force the fan would continue to do its job effectively. As soon as the aerodynamic force starts winning over the primary force, the effectiveness of the fan starts to decreases causing problems and wastage of energy reflected in the medium frequency movements and extremely slow movement (slower than the primary one).

Now let us consider the movement of the bearings (assume anti-friction bearings). As soon as a bearing starts moving two forces immediately come into play. The balls or rollers want to move in a particular direction (decided by the geometry of the bearing and the primary motive force which gives rise to the centripetal acceleration acting towards the center) as opposed to trying to fly off in a tangent but bounded by the outer race of the bearing. As the balls move against the inner race the opposing force that comes into play is frictional force, which we try to reduce through proper lubrication. And as the balls tend to fly off (which it actually does when the balls enter the non-loaded zone) it hits the walls of the outer race and tries to damage it. The only thing that prevents the damage is the extent of the space provided as running and radial clearance and the relative wear of the bearing running surfaces. Hence if the radial clearance is more than necessary the outer race of the bearing would tend to get damaged faster. This would be reflected in the medium and high frequency movements. Higher the rate of damage to either the inner or the outer race more would be the reflection we would find in the rapid cycle movement of the signatures. Similarly as the ball or the roller presses on the inner or outer races as the case might be the material or the lubricant film opposes the movement. If the centripetal force wins over the upward force exerted by the lubricant film or the bearing material itself then the bearing surface gets damaged in no time, which is then reflected immediately in the rapid movement phase (the high frequency signals).

Now let us consider the interactions between the fan blades and the bearing. As the blades develop unbalance the centripetal force in the bearing becomes higher and exerts more force than the lubricant film can exert back thus damaging the bearing. This would be immediately reflected both in the slow movement (the fundamental) and the rapid movement part of the signature (the high frequency zone). Such development of relationship through interactions is governed by another principle. It is called the Quantity to Quality. That is as the quantity (say for example, the amount of unbalance) increases the quality changes accordingly (the degree of damage). Beyond a certain point the system would suddenly collapse. 

Hence we can summarize the two principles involved in reading movements in Vibration Signatures as:

a) The Principle of Unity in Opposites

b) The Principle of Quantity to Quality

The change in state can be aptly described by the following diagram that reflects 'movement'.

Click here to download:

Uncertainty.PPT (212 KB)

(download)

Click here to download:

Uncertainty.PPT (212 KB)

Hope we are now clear about how the three types of movement (slow, medium and fast) are related to each other and how the interaction of the movements produce the pattern of the system, which we call the signature.

In the next parts we would develop the ideas in more details with examples and add more principles as we go along.

Nature furnishes a wealth of examples of the nature of 'relationships' that leads to chaos, complexities, emergence, uncertainty and transformations -- embraced by the Rapidinnovation model. 

In this post we would discuss one of the fundamental laws that relates two fundamental terms quantitiy and quality. We observe in Nature that quantity changes the quality of an emergence. Even a small quantity can produce a dramatic effect on the output quality or create a dramatic emergent pattern. This would give innovators a clue as to what we might use to create new relations, new systems, new products or simply solve nagging social and business problems. 

For instance, let us examine the relation between the different kinds of electromagnetic waves and their frequencies, that is, the speed with which they pulsate or vibrate at a given energy level.

Maxwell’s work showed that electromagnetic waves and light waves were of the same kind. However, at a later date, Quantum mechanics proved that the situation is much more complex and contradictory, but at lower frequencies, the wave theory holds good.

It is interesting to note that the properties of different waves is determined by the 'number of oscillations per second' or Hertz (the technical term used in the study of vibration).

The difference squarely lies is in the frequency of the waves, the speed with which they pulsate or the frequency of vibration. Hence it is quite clear that the property (or quality) of the waves changes (an emergent property) when the frequency (or quantity) changes. This change of property implies a change of behavior too. That is to say, quantitative changes give rise to different kinds of signals that differ in quality.

Translated into colours, red light indicates light waves of low frequency. An increased frequency of vibration turns the colour to orange-yellow, then to violet, then to the invisible ultra-violet and X-rays and finally to gamma rays. If we reverse the process, at the lower end, we go from infrared and heat rays to radio-waves. Thus, the same phenomenon manifests itself differently, completely depending on the frequency of vibration (higher to lower frequency). And this is determined by the quanity of energy we add or substract.

Interesting to note that as we move up the frequency ladder the emergent behavior changes from 'fields' to 'waves' and then to 'particles'. This is an important insight, the significance of which we would understand in a moment.

Thus Quantity changes into Quality.

Refer the Electromagnetic Table below.

Source: R. P. Feynman, Lectures on Physics, chapter 2, p. 7, Table 2-1.

The Innovators' Field Day.

Application of this law to both engineering and mangement can make any innovator or problem solver very happy.

This is because, as innovators or problem solvers we may cleverly use this law to innovate.For example, the microwave oven is based on this principle. Or invention of infra-red ports, mouses and thermal imaging are based on this principle. Similarly, NASA effectively uses cosmic rays to cure and heal astronauts orbitting the space for months. Likewise we can also understand as to how the use of CFL (compact flurorescent lamp) can affect our health. Or for example, we also notice how low frequency electromagetic radiation affects our hearts and anti-friction bearings in machines alike (fields).

Similarly, when we apply the principle in management systems we can also effectively use the concepts of fields, waves and particles all differeing in energy content, where all changes in management systems are composed of low frequency slow cycles -- fields -- the culture, ethics, vision and strategy of the company and faster cycles of change (medium to high frequencies) which are in the form of waves (general improvement initiatives for a short duration of time) and particles (focussed improvements). It is fair to admit that both low, medium and high frequency cycles co-exist, just as it does in Nature. 

It would not be therefore surprizing to see Design and Systems Thinkers use this prinicple to effectively bring about social changes in fields like health, education and sustainable living. 

And it would also not be difficult to envisage how designers might use this principle to design effective machines and systems (energy, transportations etc) to reduce global energy consumption and global warming.

And architects can also bring about dramatic changes by using the same prinicple of Quanity to Quality to bring about unique relationships between human beings and their dwellings and their energy consumption and their activities and of course their pets.

They are all important for the brave new world that lies before us begging our intelligent thinking and action.

Changes in matter are always qualitative in nature. Such qualitative changes can be best understood by observing patterns like the way we find them in frequency spectrums, wear debris slides and infra red thermal images. Such patterns can also be noticed in organizations and societies.

The existence of qualitative changes in matter exhibited through patterns was known long before human beings began to think more deeply with the help of physical sciences. With the advent of atomic theory we started to appreciate this phenomenon more deeply. In the early days of science we took changes of state from solid to liquid to gas as something that occurred naturally, without exactly knowing why. It is only now that such phenomena are being properly understood.

Chemistry made great strides forward in the 19th century. A large number of elements was discovered. But, rather it looked like the confused situation which exists in particle physics today. Indeterminate Chaos reigned.

Order was established by the great Russian scientist Dimitri Ivanovich Mendeleyev who, in 1869, in collaboration with the German chemist Julius Meyer, worked out the periodic table of the elements, so-called because it showed the periodic recurrence of similar chemical properties.

Note the use of word 'periodic'. This is the building block of pattern making out of which we make sense of the world around us. It is the periodic repetition arranged in a certain manner that forms patterns across different levels. We now have a sophisticated word for that. It is called 'fractals'.  

The existence of atomic weight was discovered in 1862 by Cannizzaro. But Mendeleyev’s genius lay in the fact that he did not approach the elements from a purely quantitative standpoint, that is, he did not see the relation between the different atoms just in terms of weight. Had he done that by mistake, he would never have made the breakthrough he did. From the purely quantitative standpoint, for instance, the element tellurium (atomic weight = 127.61) ought to have come after iodine (atomic weight = 126.91) in the periodic table, yet Mendeleyev placed it before iodine, under selenium, to which it is more similar, and placed iodine under the related element, bromine. Mendeleyev’s method was vindicated in the 20th century, when through the investigation of X-rays his arrangement was proved correct. The new atomic number for tellurium was put at 52, while that of iodine was 53. The breakthrough idea was to look for patterns. 

The whole of Mendeleyev’s periodic table is based on the law of quantity and quality, deducing qualitative differences in the elements from quantitative differences in atomic weights.

This understanding helps us unravel some of nature's mysteries. These are:

a) Quantitative changes leads to qualitative changes

b) Even extremely small quantitative changes often brings about dramatic qualitative changes.

c) All qualitative changes can be understood by patterns.

d) Any qualitative changes that are always exhibited through patterns can't be measured. So, important qualitative transformations can't be understood through measurements of any kind. It can be understood 'wholistically' through patterns only.

e) Patterns or qualitative changes repeat themselves over and over again in a system. Such a phenomenon is called 'fractals'. This happens in a self organizing fashion and the pattern that emerges is the part of the emergent property of the system.

f) Fractals exist at different levels in a system. This indicates that reality of a phenomenon exists at different levels. This is what we call as 'parallel reality'.

g) So by closely studying one fractal we get to understand the nature of all other fractals. That is we start from a part and understand the whole. This allows us to see the part and the whole at the same time.

h) It follows, that change in the pattern at the highest level changes patterns at other levels automatically in a spontaneous manner.

i) However to make an effective change we look for the smallest change to be made with the least effort and time to bring about substantial and sustainable changes in the system.