Plainly stated, the burgeoning cost of maintenance is a serious business problem. According to DuPont, “maintenance is the largest single controllable expenditure in a plant: in many companies it often exceeds annual net profit.” One major U.S. automotive manufacturer has a maintenance staff of between 15,000 and 18,000, all plants combined. They say “85% to 90% is crisis work” (breakdown).

While preventive maintenance, when well implemented, has been shown to produce savings in excess of 25 percent, beyond that its benefit quickly approaches a point of diminishing return. According to a Forbes Magazine study, one out of every three dollars spent on preventive maintenance is wasted. A major overhaul facility reports that “60 percent of hydraulic pumps sent in for rebuild had nothing wrong with them.” These inefficiencies are the result of maintenance performed in accordance with a schedule (guess work) as opposed to the machine’s true condition and need.

Most recently, predictive maintenance (also known as condition monitoring) has been leading the way to additional savings over preventive maintenance. The use of real time or portable instruments such as vibration monitors, thermography, ferrography, etc. has been effective at recognizing the symptoms of impending machine failure. The major benefit is the availability of an earlier warning, from a few hours to a few days, which reduces the number of breakdown “catastrophic” failures. Predictive maintenance is usually implemented concurrently with preventive maintenance and targets both the warning signs of impending failure and the recognition of small failures that begin the chain reaction that leads to big failures (i.e., damage control).

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Optical particle counters (OPC’s) have a long history of use in industrial hydraulic applications. Traditionally, their success has been limited to scientific laboratories and other highly controlled environments. However, in recent years, attempts have been made to apply the use of OPC’s to the particle counting of used hydraulic fluids and industrial lubricants. As a result, serious concerns have been raised regarding the accuracy and reliability of OPC’s in such applications. The objective of this bulletin is to present important facts from reliable and documented sources for the general benefit of existing or prospective users of OPC’s. As particle counting moves into the mainstream of machine condition monitoring, users must have reliable information to identify and select appropriate technologies.

The post The Usefulness of Particle Counting in Oil Analysis appeared first on Tesibis.

Inspection, in its most basic form, has been around forever. However, like most things in life, what you get out of an activity depends entirely on what you put in. This column is about radical reinvention of the whole concept of machine inspection. It has little to do with conventional practices of doing daily machine rounds.

With Inspection 2.0, you don’t just “look” at a bearing, seal, coupling or pump. Instead, you “examine” these components with a keen and probing eye. Inspection 2.0 is intense and purposeful. It seeks to penetrate and extract information from what’s been referred to as machine sign language. Inspection 2.0 requires polished linguistic skills to translate this sign language into prescribed activities and instructions that stabilize reliability.

The technologies of machine condition monitoring have been advancing at a near break-neck pace in recent years. These innovations will continue for decades to come. Still, for the vast majority of machines, there is currently no fault-detecting technology more effective than the razor-sharp and relentless focus of a human being.

The potential of a human being as a condition monitoring instrument is enormous. This potential depends on transformation, specifically from the going-through-​the-motions inspections of the past to mission-intensive detective work inspections of the future. That is the essence of Inspection 2.0.

The post Why Inspection 2.0 Is Your Best Strategy for Early Fault Detection appeared first on Tesibis.

No warning or short-warning failures are the worst kind. Think of a tire. It can wear out slowly over thousands of driving miles or rupture suddenly, at full highway speed, from a random piece of road debris. You can monitor tread loss over time and conveniently schedule a tire change. Conversely, who could predict the sudden appearance of a sharp piece of iron?

Fault bubbles are sudden-death conditions in waiting. They haven’t ruptured, but they are about to. Similar to a tire, fault bubbles can burst instantly. Unlike the tire, most fault bubbles in industrial machinery can be revealed by condition monitoring, which includes the careful examination by a skilled inspector. Once detected, the root cause can be arrested or at least mitigated.

In past columns, I’ve mentioned the P-F interval. As a review, “P” is the point at which a failure (in progress) is first detected, while “F” is the end point of functional inoperability. Although the P-F interval is a theoretical concept that has useful application, it is rarely applied in real-world machines. This is because the real world comes with many variable events. These events distort the predictability of the P-F interval.

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It has been extensively documented and widely stated that particle contamination is the number one cause of wear and failure of hydraulic components. The problem is generally more pronounced than in other types of machinery incorporating circulating systems that use sirnjlar types of oils. This heightened contaminant sensitivity is due to the high pressures and tight tolerances which are characteristic of modern hydraulic machines. Pressure is known to have a disproportionate effect on contaminant sensitivity.

Much has been learned in the past three decades about contamination control at both a laboratory research level as well as the real-world deployment of this knowledge in machinery-intensive industries. Case studies have flourished on the practical and economic benefits of maintaining hydraulic systems and fluids at extreme levels of cleanliness. Hence, the speculation is gone relating to the business case and strategies that produce savings and benefits to user organizations. For many owners of hydraulic systems the opportunities of planned cleanleness are like low-hanging fruit that is ripe for picking. This chapter summarizes this body of knowledge and the value-producing strategies needed to control particle contamination in hydraulic fluids.

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In the world of maintenance, there are two kinds of companies – those who are modernizing their maintenance programs and those who will. Companies on the trailing edge face one of two risks depending on their industry and geography:

Losing revenue to competition as demand for production capacity heats up.

Losing profits to competitors who export from low-cost labor markets abroad.

Averting these risks requires a process called change. Perhaps you’ve heard of it. Change can be evolutionary or revolutionary. Evolutionary change is incremental, more manageable and lower in risk.

However, for those laggards who have put off the inevitable, time may be running out. For them, the end to business- as-usual has arrived.

Catching up to already fast-paced competitors who are further along in the maintenance evolution may require sizeable short-term budgets for training, new tools and knowledge technologies.

Some of these companies may have to leapfrog over evolutionary and move straight to revolutionary. This would involve rapidly reinventing their work environment, maintenance practices, metrics and culture.

Instead of controlled and well-managed incremental improvements, breakthrough innovations may be required instead. Revolutionary change can be disruptive and often a source of stress and distress in the workplace.

The post Evolution of Maintenance Man appeared first on Tesibis.

I have written several articles on inspection recently, as I strongly believe it is foundational to condition monitoring, machine reliability and asset management. My last Machinery Lubrication column introduced the term “Inspection 2.0” to differentiate conventional inspection practices from the intense, probing and purposeful methods needed to optimize benefits. As common as inspection activities may be in any plant, Inspection 2.0 is largely untapped in my opinion. In fact, it is delusional to imagine world-class reliability without the coexistence of world-class inspection.

Inspection 2.0 borrows from many battle-tested philosophies, including the practice of autonomous maintenance advanced by total productive maintenance (TPM) doctrine. However, not detailed in these philosophies is the “how-to” to move an organization past the inspection status quo to the real game-changing opportunity that eludes their view. I plan to address these differences and the “how-to” tactics in several upcoming Machinery Lubrication articles.

This article introduces the concept of machine readiness as a critical enabler to Inspection 2.0. An inspector who is eager to determine the state of machine health – good or bad – needs help from the machine. What hurts, where does it hurt and what are the symptoms of being hurt? Information exchange, like basic communication, is a two-way street. There is a need to enhance the quality of machine-transmitted conditions so the inspector gets a clear and complete picture of the state of the machine’s health.

The post Getting Machines to the Proper State of Inspection Readiness appeared first on Tesibis.

Condition monitoring should never be limited to a single technology or method. Instead, it should combine and integrate an optimum selection of purposeful tools and tasks. Condition monitoring can be largely technology based but can also be observation or inspection based.

Most machines share condition monitoring and inspection needs with many other types of equipment. This is because they have components and operating conditions in common, i.e., motors, bearings, seals, lubricants, couplings, etc. At the same time, their operating conditions and applications may demand unique inspection requirements. These influence failure modes and machine criticality.

As discussed in previous columns, inspection should be viewed with the same serious intent as other condition monitoring practices. In my opinion, a world-class inspection program should produce more “saves” than all other condition monitoring activities combined. It’s not an alternative to technology-based condition monitoring but rather a strategic and powerful companion.

The technologies of infrared thermography, analytical ferrography, vibration analysis, motor current and acoustic emission are generally used to detect active faults and abnormal wear. Conversely, a well-conceived inspection program should largely focus on root causes and incipient (very early stage) failure conditions. Detection of advanced wear and impending failure is secondary.

The post How to Measure the Effectiveness of Condition Monitoring appeared first on Tesibis.

The well-known KISS principle (keep it simple stupid) was first coined in the 1960s and began widespread use in the U.S. Navy shortly thereafter. While it started as a design principle for engineers, it has since been applied to any activity or creative endeavor that has had the propensity to become unnecessarily complicated.

What becomes overly complicated also becomes, by default, poorly understood and sparsely used. Conversely, the greater genius in design and engineering lies in achieving the design objective through simplicity and pureness of form.

This can be applied to the world of oil analysis in many ways. Increasingly, oil analysis has become engulfed by complex analytical chemistry and mathematical algorithms. This science is successful when it takes the complicated, such as an array of particles of varying shapes, sizes, textures, colors and compositions, and puts their formation into plain English (e.g., cutting wear on cylinder walls).

The post How to Visually Inspect the Health and State of Oil appeared first on Tesibis.

Condition control is defined as the interactive processes of condition monitoring, condition analysis, and condition response. A model is presented which employs the use of expert systems to achieve real-time condition control of a hydraulic system. The approach focuses on the use of fuzzy logic to achieve machine intelligence to monitor and analyze pre-degradation ‘incipient’ failure and impending conditions. Also discussed are the corresponding real-time ‘reactive’ condition responses, coupling system control with condition control.

The post Model of a Fuzzy Logic Expert System for Real-Time Condition Control of a Hydraulic System appeared first on Tesibis.

The monitoring of particle contamination in lubricating fluids is a critical indicator of incipient and impending failures. Recent research, under both laboratory and field conditions of the contaminant sensitivity of bearings, reveals a well defined cause and effect relationship between contaminant levels and relative machine life.

This paper discusses the contaminant sensitivity of bearings as well as turbines, diesel engines, gear systems, and hydraulic systems. Also discussed is the benefit of applying contaminant monitoring to both proactive and predictive maintenance programs. Proactive maintenance is the process of monitoring root causes (pre-degradation conditions) as opposed to predictive maintenance which focuses on impending failure conditions.

The post Particle Contamination — Both a Cause and a Result of Mechanical Failure appeared first on Tesibis.

There are 8,760 hours in a year. Few plants manage to produce at full capacity for all of those hours. Instead, there are periodic production stoppages due to tooling changes, product changes, scheduled PMs/inspections and unscheduled downtime (reliability issues). Every hour the plant’s assets aren’t utilized is an hour of lost revenue and profits.

Sadly, many plant managers play games with the numbers by ignoring the potential controllability of “scheduled” downtime. Yes, tooling and product changes are unavoidable, but in most other circumstances, there are often practical ways to minimize lost production from scheduled shutdowns.

This can be seen in the difference between typical and top performers in the same industry. For instance, a standard 900-megawatt coal-fired power plant may produce at 86-percent capacity (44 weeks per year), while top performers can exceed 94 percent (48 weeks per year). This is a difference of four weeks of productivity.

Still, no classification of work stoppage causes more agony than unscheduled downtime. The reasons are quite obvious, as a recent online survey of Machinery Lubrication readers discovered. Following is a list of the top reasons unscheduled downtime is so unwelcome:

• Production losses and schedule delays (business interruption)
• Lost revenue and profit (unhappy management/ownership)
• Promised delivery dates are missed (unhappy customers)
• The blame game and damaged relationships between operations and maintenance (morale issues)
• Hurried (botched) repairs cause future problems (cycle of despair)
• Lack of available replacement parts and skilled trades prolongs the downtime interval
• Repairs are at a “cost premium” due to rushed parts purchases, use of overtime labor and collateral damage
• Scheduled “proactive” tasks are replaced by chaotic reactive tasks (leads to future problems)
• Increased work pressure and job stress (job satisfaction issues)
• Safety risks due to rushed work, unskilled work, inferior parts, cutting corners, job stress, etc.

The post The Wrath of Unscheduled Downtime: Why Oil Analysis is a Wise and Effective Defense appeared first on Tesibis.

With the widespread use of plant-level particle counters, maintenance organizations are becoming more sophisticated and skilled in the management and control of oil cleanliness. This has led to the discovery of a host of new tactics and practices that involve combining the particle counter with other important onsite oil analysis tools and methods.

Contamination can be defined as any unwanted substance or energy that enters or contacts the oil. Contaminants can appear in many forms, and can be highly destructive to the oil, its additives and machine surfaces. It is often overlooked as a source of failure because its impact is usually slow and imperceptible yet, given time, the damage is analogous to eating up the machine from the inside out. While it is not practical to attempt to eradicate contamination from in-service lubricants, control of contaminant levels within acceptable limits can be accomplished and is vitally important.

The post Why Onsite Particle Counting Makes Sense appeared first on Tesibis.

Costly particulate contamination slowly degrades and jams machine components causing product defects, shorter machine life., increased production downtime and decreased energy efficiency. Even the smallest amount of water, or the most microscopic particles, can ·eventually grind a machine to a halt. Yet, maintenance has historically been a ·reactive type activity .. When a machine breaks down, maintenance personnel give the failed components the “4R Treatment”- that is remove, repair, rebuild and/or replace. When evidence suggests that material degradation and/or deterioration is taking place at an accelerated rate, the cause has been determined and. action taken to correct the problem. In today’s world when there are increasingly complex- systems., maintenance personnel must supplement such traditional reactive maintenance Practices with proactive methods that can identify aberrant root causes of failure long before materials or component performance degradation occurs. No maintenance discipline has previously taken the micro view on machine damage concentrating on the· causes instead of the symptoms of wear. Proactive maintenance is that discipline, and it is quickly being recognized worldwide as the most important means of extending machine life.

The post A New Approach to Maintaining Industrial Equipment appeared first on Tesibis.

A proactive maintenance approach has been particularly successful in reducing or eliminating one of the most serious equipment maintenance problems: contamination of lubricant or hydraulic fluid systems. According to the bearings division of 1RW, “contamination is the number one cause of bearing damage that leads to premature removal.” Caterpillar states that “dirt and contamination are by far the number one cause of hydraulic system failures.” Similarly, J.I. Case states that “systems must be kept clean, spotlessly clean, in order to achieve the productivity they are capable of.” Finally, Oklahoma State University reports that when fluid is maintained 10 times cleaner, hydraulic pump life can be extended by 50 times (Fig. 1 ).

The most common types of contaminant induced failures in machinery are wear, sticking, seizure, erosion and corrosion. Contaminants can include solid particles, moisture, air, chemicals and other foreign materials. Figure 1 – Cleaner hydraulic fluid extends pump life.

The rate at which contamination enters a system is typically underestimated, and the effectiveness of filters in removing this contamination is often overstated. According to a study of hydraulic equipment at Oklahoma State University, “it has been demonstrated that apparent ingression rates of 10-100 million particles greater than 10 microns (per minute) characterize field systems (Figure 2).” Filters often have great difficulty removing these high contamination levels since they are subject to frequent changes in temperature, fluid viscosity, pressure, and flow; plus the effects of shock, vibration and fatigue. Other common problems are filter bypass valves that are stuck open, damaged or missing filter gaskets, and filters that are installed crooked or backwards.

The post Contaminant Monitoring Targets Root Causes of Machinery Problems appeared first on Tesibis.

Process plants and manufacturing companies have machinery lubricated by mineral-based or synthetic fluids and other machinery powered by lower viscosity hydraulic fluids. We define equipment of this type as fluid-dependent systems. Examples of this include gear boxes, process pumps, gas compressors, speed reducers, blowers, hydraulic metal working machines and machine tools.

When machines have wear, corrosion and associated problems that eventually lead to corrective action, we categorize these problems as internal state failures. Often, equipment operates infrequently, under very low loads, and away from the main production processes. In such cases, it may be perfectly acceptable to operate this equipment with scheduled maintenance activities or simply on a breakdown basis.

The post Establishing and Maintaining Levels of Cleanliness [in Lubricants] appeared first on Tesibis.

Inspection 2.0 is rooted in some of the most fundamental and time-honored maintenance principles. One of them is total productive maintenance (TPM). Today, it’s hard to play an active role in the field of maintenance and reliability without encountering and embracing TPM. Honestly, it is delusional to think otherwise.

World-class maintenance organizations understand the intrinsic value of a well-tuned and culture-driven TPM program. World-class TPM programs are fundamentally powered by keen observation. You can’t fix what you can’t see. Therefore, all progress hinges on the power of observation. Allowing you to see is the bedrock. Improve the quality of inspection and, by default, you improve the quality of TPM and all the benefits that TPM seeks to achieve. It’s that simple!

The origin of TPM can be traced back to the Japanese automobile industry in the 1960s. It has many similar elements to the quality movement that was advanced in Japan during the same period. However, it wasn’t until 1988 that the western world learned of TPM when two seminal English texts were published on the subject by Seiichi Nakajima. From that point, TPM spread across the vast global maintenance and reliability landscape.

TPM has similarities and overlapping features with other branded maintenance philosophies, including reliability-centered maintenance (RCM), condition-based maintenance (CBM) and asset management (see Figure 1). However, its strongest difference is the active and responsible role of machine operators and small groups toward maintenance prevention and improved asset utilization.

The post Inspection 2.0: The Cornerstone of World-Class TPM appeared first on Tesibis.

Condition monitoring can be easily performed by following a few simple principles. Among these principles include monitoring two sets of conditions:

1. The operating and environmental conditions that precede failure, and
2. Early-stage failure symptoms

Several models are presented that show the benefits of monitoring machine conditions, as well as the consequences of ignoring them . Also discussed is the integration of both proactive and predictive maintenance techniques to extend machine life.

The post Interpreting Contaminant Analysis Trends into a Proactive and Predictive Maintenance Strategy appeared first on Tesibis.

The majority of wear related failures occur as the direct result of particulate contamination. A recent article published in Lubrication Engineering magazine concludes that more than 82% of wear related losses are contaminant induced. And, the largest portion of this is abrasive wear; the direct result of particles wedged between rolling and sliding surfaces.

According to work done by SKF, bearings can have “infinite life” when the influence of particle contamination is eliminated. In some cases more than a 75-times life extension can be achieved by maintaining exceedingly clean lubricating fluids. It is also worth noting that the penalty associated with a contaminated lubricant is identical to that of using a lubricant with just 25% of the recommended viscosity.

There are few forms of internal machine failure that don’t release particles into the lubricant; detecting increases in particle contamination can be extremely important. Figure 1 lists some of the failure types detectable using contaminant monitoring.

As a predictive maintenance technique, abnormal particle trends are the early symptoms of several non-particle induced conditions. Once the abnormal trends are recognized, a more precise assessment of lubricant condition or machine malfunction can be pursued.

The post Lubricant-Based Techniques for Condition Monitoring of Non-Circulating Gear and Bearing Systems appeared first on Tesibis.

The field of maintenance technology is going through a revolution of change. Gone are the days when a machine had a predictable service life, after which it was replaced, continuing the cycle. Today, machinery and equipment can be maintained to achieve useful operating lives many times that attainable just a few years ago.

Historically we’ve relied on the popular practice of predictive maintenance and condition monitoring to combat rising maintenance costs. Today we implement predictive maintenance with greater confidence and precision. These early warnings have proven effective at reducing the magnitude of failure and amount of unscheduled downtime; however, no real progress has been made in reducing frequency. Any maintenance strategy targeting the reduction of failure frequency must address lhe fundamental causes of failure. Such a strategy of eliminating causes would be “proactive” to failure, not “reactive” to failure.

This approach, known as proactive maintenance, is the latest and most promising wave of new maintenance technology. Its fundamental and logical approach seems likely to gamer deeply entrenched inroads into the cost-driven maintenance industry this decade. Case studies documenting cost reductions exceeding 90% have provided a solid lead for others to follow seeking similar savings.

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