By Stacy Heston, CLS, PMP, CMRP, OMA, Lubrication Subject Matter Expert, Allied Reliability Inc.

Lubrication practices are often overlooked as a potential time and money saver for a plant.  However Cargill Charlotte has found that by optimizing their lubrication task intervals, utilizing specific grease volumes, and implementing an oil analysis program, the overall reliability of their manufacturing process, as well as, the healthy status of their lubricated components has increased.
In 2009, Allied Reliability performed a Reliability Centered Lubrication Current State Analysis at the site to determine the state of the lubrication program.  Through the assignment of a score to different lubrication activity and practices, the site’s lubrication program was benchmarked on several parameters including program documentation, management structure and practices, storage and handling, etc.  By assigning a score, the benchmarking activity becomes more objective and less subjective allowing for a definitive path forward.
When Allied Reliability arrived on site, “the site had run amuck with lubricants everywhere, it was all about the flavor of the month…” where lubrication was concerned, and “no structure existed for the scheduling of lubrication tasks,” says Andy Nolan.  As a result of the Current State Analysis, it was determined that a RCL walk down was needed to bring the site up to speed with industry best practices for lubrication.
Shortly after the Current State Analysis, Allied Reliability began the development of a Reliability Centered Lubrication Program at the site.  The program design began with a full walk down of all lubricated components on site.  During the walk down phase, all data pertinent to the development of lubrication specifications, interval calculations, and lubricant quantity calculations is gathered.  This phase sets the stage for the remaining program design as the accuracy and content of this data is the core to a strong program.
During the walk down, opportunities for optimizing intervals are identified as well as opportunities for optimizing the lubricant list.  Optimization does not always mean an increase in intervals or a decrease in the number of lubricants on site, rather it is the assignment of calculated intervals that are specific to the component and takes into account the specific operating conditions the component is exposed to.  Essentially, the same bearing may be exposed to wash down practices and heavy debris requiring an increased interval, such as 30 days to account for these environmental exposures.  However, the same type of bearing operating at the same speed with limited exposure to moisture and no exposure to debris may have an interval of 360 days.  This deviation in intervals means that the bearing with the more aggressive environment and operating conditions receives the more aggressive treatment.
When the Charlotte site began the implementation phase of their RCL program, the lubricated components were in poor health.  Approximately 60% of the oil lubricated assets were considered to be in the red, or in a state that did not meet industry best practices for contamination control, operating temperature, etc.  Within three months, the percentage decreased to approximately 40%.  By the end of 2010, 100% of all oil lubricated assets had achieved a green status.

Components were easily converted from a red state to a green state through the implementation of oil analysis, off line filtration, and monthly inspections.  Oil analysis aids in the identification of in use lubricants that required filtration to clean up solid contaminates, needed refreshing due to changes in additive levels and lubricant properties, or need complete replacement.
Previous to the implementation phase, the site utilized a time based oil change methods, had a multitude of lubricants with no specific requirements for each component, utilized screen breathers, and had no structure for the inclusion of filtration.  Lubricants were stored in drums and in areas that did not provide a clean, temperature controlled atmosphere.  The overall program lacked structure with regards to regrease intervals and amounts, as well as, oil analysis and oil change intervals.
The implementation phase of the RCL Program Design included recommendations for component modification with items such as desiccant breathers, quick connect couplings, level gauges, and sample valves.  These modifications provide multiple benefits for the lubrication program as well as the plant operating structure as a whole.  Level gauges and sample valves allow lube technicians to perform level checks and sample collection tasks with the machine running.  Without these modifications, the machine and possibly the product line would need to be down for the completion of these tasks.  It also saves time from a labor perspective.  A dipstick level indicator involves several steps to determine the level and exposes the lubricant to the possibility of contamination, where as a visual level gauge is nothing more than a quick peek then walk on to the next component.
The Charlotte site followed some very basic steps to manage the program implementation starting with the incorporation of desiccant breathers and other types.  After some experimentation with different types of breathers, there was an eventual shift to the use of trap and hybrid breathers based on the components size and location within the plant.  Of all the modifications, breathers are the least evasive to install, and limits the amount of debris able to enter the sump down to 3µ in size.
The second step included the conversion of mineral based oils to synthetic based oils in the smaller sump components.  Using the current practice of 6 or 12 month oil drains, each sump was converted during the next scheduled oil drain task.  At that time, new intervals of 12 or 18 month were implemented for each sump.  This step applies only to sumps that are too small for oil sampling.
The third step was the implementation of oil sampling practices on sumps within the 4 to 22 gallon range.  This implementation allowed for the extension of oil drains through the monitoring of the lubricant health.  Unlike the second step, these components were not immediately converted to a synthetic oil.  Rather the current lubricant was monitored and cared for until such time the oil analysis results showed a break down in the lubricant properties.  Once the lubricant properties began to degrade, an oil change with conversion to a synthetic occurred.  This maximized the life of the lubricant that was in service before change over without harm to the component.
*During lubricant drains, additional modifications were implemented while the sumps were empty such as the installation of level gauges, quick connects, and sample valves.
Once the oil lubricated components had been addressed, the fourth step was implemented.  The fourth step was the mass implementation of the grease lubrication routes that were developed based on the walk down phase.  These routes were provided in an electronic format which is downloadable to a pda, or other handheld device.  The routes were grouped together based on location within the plant, lubricant required, and interval.  The interval and re-grease volumes are calculated using gathered data to ensure the right amount of lubricant is delivered at the right time.
At the onset of the RCL design, this location had 1 overworked lubrication technician.  Now, they have 1 lubrication technician who is able to complete all required tasks within a timely manner because a solid program structure has been implemented to address all aspects of lubrication.  Task intervals have been optimized to ensure over and under lubrication is not an issue, and oil drain intervals have been extended.  Additionally, lubrication related failures have decreased allowing focus to shift from putting out fires to maintaining the current state.
“We now have a set program that anyone can follow with component state data being collected regularly to ensure appropriate actions are taken to avoid lubricant and component failure.  We have structure and focus.”

By Angie Meinsma, Oil Analysis & Lubrication Technician, Allied Reliability

It is often said that oil is the “lifeblood” of machines and equipment. Taking oil samples from rotating equipment for condition monitoring is like taking blood samples from a human. Analysts look for abnormalities within the fluid. The goal is to find faults, treat the condition, and extend the life expectancy.

When used properly, fluid analysis becomes a valuable diagnostic tool that can reduce maintenance costs, increase productivity, and boost company profits. When used in conjunction with other diagnostic technologies such as vibration analysis and thermography, well-executed fluid analysis strategies can detect a variety of equipment problems before they become failures and give users the valuable time necessary to make decisive, well-informed maintenance decisions. Time has allowed most people and organizations to see the value of integrating the condition monitoring resources for root cause management; they team up to provide control over the root causes of machine failure. Vibration analysis detects abnormal running conditions, such as unbalance, misalignment, and looseness, while oil analysis detects overall lubricant quality and contamination.

The three major reasons for lubricant failure are:
• Contamination – Component life is dependent on the cleanliness of the lubricating fluid. The cleanliness of any lubricant is dependent on oil handling practices, top up procedures, and the quality of both air breather and oil filtration.
• Oil Degradation, specifically oxidation – Oxidation occurs when atmospheric oxygen combines with hydrocarbon molecules and undergoes a chemical change. This chemical change results in the catastrophic and permanent change to a different chemical makeup for the oil molecule. The rate at which the oil molecules react with the oxygen depends on a number of factors, but the most prevalent are temperature and/or additive depletion.
• Additive Depletion – Additives are consumed or chemically depleted while performing their function. After being totally consumed, the additive can no longer provide the special property it performs for the base oil. The lubricant’s performance then suffers, and again the oil must be changed. Each one of these additives has a finite life, and when they reach the end of that life, you can forget about any advantage they helped provide. Some machines rely heavily on this advantage, and when it goes, so does the life expectancy of the machine.

These three factors are why we change oil. No matter what you do, eventually you will have to change it. However, the cleaner, cooler, and drier it is kept, the longer you will be able to go between those changes.

In order to establish appropriate maintenance strategies for your equipment, it is necessary to first understand the failure modes that are inherent in the parts and components that make up your asset base. Once the failure modes are identified, the proper condition monitoring and preventive maintenance tasks can be put in place to identify the warning signs of those failure modes or defects, keeping in mind that the earlier we identify an issue, the better. Unfortunately it is not uncommon for lubrication to be overlooked during the maintenance strategy design session. This is often due to the fact that lubrication is rarely thought of as an integral “part” that comprises your asset. The reality of the situation is that it is in fact a vital part and lubrication failure holds the same consequences as a bearing or coupling failure. Ultimately, the asset fails to perform according to it’s designed function. As with all failure modes, certain condition monitoring technologies are better suited to identify certain failures. This is why lubrication analysis is an integral piece of your maintenance and reliability initiatives.

When condition monitoring technologies are used in conjunction with lubrication analysis, the findings and recommendations are typically far superior. This approach ensures comprehensive coverage consistent with the the likely failure modes of your critical equipment and allows the earliest detection capabilities possible, which foster root cause issue identification. This approach affords ample time to plan, schedule, and perform recommended corrective actions and provides the highest possible return on your maintenance investments.

By: T.J. Garten, IR/MCA Specialist

Bean Conditioner – Horizontal Rotary Vessel

Synopsis

Fault

Summary of Action

Supporting Data

Figure 1: Pre-repair Demodulation Spectrum

Figure 2: Pre-repair Historical Data

Figure 3: Pinion Wear

Figure 4: Broken Welds on Pinion Gear Pillow Block Pedestal

Figure 5: Post-repair Demodulation Data

Conclusion

The corrective action taken during the repair of the failed trunnion bearing resulted in an altered elevation of the rotary vessel. The attempts to adjust for this were inadequate and resulted in a changed mating pattern between the pinion gear and bull gear assemblies. Over time, the increased impacting caused the pinion shaft to deflect, breaking the welds on the pedestals. This deflection also caused an angular misalignment between the pinion shaft and the gearbox output shaft. The level of misalignment may also have been affected by utilizing dial indicators for precision shaft alignment rather than the on-site laser alignment equipment. As the trunnion rollers wear, the clearance between the pinion gear and bull gear’s high spot decreases, resulting in increased shaft deflection. The increased shaft deflection results in transmitted vibration to the feed screw platform and torsional stress on the gearbox output coupling.Future corrections need to take into account all clearances and their effect on correlating components. Monitoring of adjusted components should be within days of adjustments and load changes. Installation of remote accelerometers on the pinion gear shaft pillow blocks would allow for quicker analysis of shaft misalignment, bearing condition, and pinion gear mesh frequencies.

By: Aubrey Green, Lead Analyst, Allied Reliability

Case Study Information:

While working as a Predictive Maintenance Technician in a paper mill, an analyst received a telephone call from the Pulping area. Their samples of white liquor were showing particles (turbidity). These particles were affecting the quality of pulp that was being produced. When these sand-like particles were processed in the paper machine, they produced a large mark. This mark lowered the quality of the paper. The department wanted to know if the analyst had any information on the process that could be causing the problem. They were particularly interested in pump vibration that would show the origins of the particles.

A quick look through the vibration data showed no issues that could be noted. The analyst asked for a simple piping diagram of the route of the white liquor from the clarifier to the digester. Armed with this information, the analyst decided to start at the beginning of the system and work to the end.

The system began with white liquor clarifiers started the system. Samples of liquor at the clarifier stage showed a few expected particles in the system. There was not enough turbidity to cause the problem the Pulping Department was experiencing. The analyst continued to study the diagram, looking for potential problem areas.

A holding tank was located before the digester. Between the clarifier and the tank there were only pipes and pumps, and the analyst decided to focus his attention on the tank. He knew he needed to find an accurate way to see what was in the tank. White liquor is extremely caustic, so dropping a weight into the tank would be dangerous. In addition, there were only one or two places to access the tank from the top.

Based on past experience, the analyst knew that the tank level could be determined with an Infrared (IR) camera. The temperature differential between the tank contents and the gas above the contents can be enough to show the tank level. The analyst had used this procedure many times in the past to confirm actual tank levels versus instrument readings. In this situation, he thought that if there was material in the bottom of the tank, it may have a temperature differential also.

Since the tank was not insulated, the image was not difficult to acquire. Using a thermal imager, the analyst took an image of the tank (Figure 1). The level of the tank was quickly noticeable. In addition, there was a wedge of material in the bottom of the tank, which was evident because the tank was known to have a flat bottom. This deposit was the result of years of particles from the clarifier settling in this tank. The inlet piping shown on the left of the image was actually acting as an agitator, mixing the particles with the white liquor before sending it to the digester.

Figure 1: Image of White Liquor Tank Showing Deposit

The analyst showed the image to the operator, who remarked, “Now we have an x-ray machine to see inside our tanks.” In this case, his comment was true.

An immediate resolution to the problem was needed, but the tank could not be taken out of service. The concentration of particles increased as the tank level lowered. Therefore, the tactical plan was to keep the tank level high enough to keep the concentration of particles at an acceptable level. The strategic plan was to clean the tank when it could be taken out of service.

Conclusion:

The deposits were removed from the White Liquor Tank during the next mill outage. Following that, the issues with turbidity were determined to be eliminated.

Dealing with hazardous chemicals in tanks and discovering problems within a containment may seem to be a daunting issue. Using the right technology in the right manner can give you insight to internal conditions and help you solve the problems in an efficient and effective manner.

Don’t Let the title fool you, this is a great and very short case study!  Allied Reliability SME Aubrey Green examines a dilemma at a salt evaporation plant in upper NY.  Read it for yourself here:

Radio Frequency Interference on Commtest VBx Series Data Collectors from Improperly Grounded Equipment

Tool Box Training was developed as a single point lesson tool for maintenance supervisors by Allied subject matter experts: Mike Gehloff, Ricky Smith and Dan DeWald. They are designed to be used once a week or every other week. These are created so a supervisor can cover the material in about 10-20 minutes. The objective is to transition a maintenance team to a higher awareness and competency level.  Below is the Tool Box Talk for Lubrication of Bearings:

Tool Box Talk: Lubrication of Bearings: Best Practices

Every year Reliabilityweb publishes an eBook on top tips, opinions and viewpoints from industry thought leaders and subject matter experts from around the world.  Doug Plucknette, RCM discipline leader for GPAllied was featured in this 2011 edition with a topic he is very passionate about:  safety as a result of a good reliabililty program.  Read it for yourself here:

Things to Do and Think About 2011- Confidence

Allied Reliability’s John Trulli and Bill Kilbey contribute to this ‘Plant Services’ Cover story demystifying the benefits and arguments that swirl around Predictive Maintenance merits, technologies and strategies.   Written by Russ Kratowicz published in April 2011 Plant Services Magazine.  Read it for yourself here:

PdM True Believers: proof of economic benefits can have an astronomical effect

“Without Poractivity in this Process Chaos Will Dominate”

Ricky Smith, CMP, CPMM; Senior Technical Advisor for Allied Reliability shares his latest addition to his a Day in the Life of a… series published in ‘uptime’ Magazine.  This article focuses on the role of a Proactive Maintenance Planner and is featured in the April/May edition of “uptime” Magazine.  Read it for yourself here:

A Day in the Life of a Proactive Maintenance Planner

Ricky Smith, Principal Advisor at GPAllied shares the basics on failure modes driven maintenance strategy through this installment of his monthly training topics.  This training is designed for a maintenance manager or reliability manager to train their staff in known best practices.  Read it for yourself here:

Failure Modes Driven Strategy: Monthly Training Topics- Journey to World Class