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Machinery Lubrication July August 2008

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CONTENTS<br />

<strong>July</strong> - <strong>August</strong> <strong>2008</strong><br />

Features<br />

machinerylubrication.com<br />

Features Continued<br />

18 Contamination Control<br />

A New Option for Keeping<br />

Your Hydraulic Systems Clean<br />

Hydraulic equipment users routinely change or clean<br />

servo valves. But is that practice really necessary? There is<br />

another solution: new additive technology for hydraulic oil<br />

that can reduce the need to frequently clean or change your<br />

servo valves.<br />

22 Case Study<br />

Storage and Dispensing Systems<br />

Complement Lube Room Procedure<br />

Making sure that every piece of machinery in the plant<br />

receives the right lubricant is critical, and it’s important<br />

that the oil is fresh, clean and free of contaminants.<br />

15 From the Field<br />

How Effective Is Your <strong>Lubrication</strong> Program?<br />

The path to lubrication excellence can be difficult to navigate. It begins when<br />

individuals and organizations become aware of the importance of their lubrication<br />

program, its impact on productivity and its direct effect on the bottom line.<br />

6<br />

18<br />

22<br />

26 Contamination Control<br />

Managing Water Contamination to<br />

Maintain Effective Steel Mill <strong>Lubrication</strong><br />

Although necessary to reduce the extreme heat generated<br />

in the processing of steel, water is among the most destructive<br />

contaminants to the circulating oil system and can degrade a<br />

lubricant in a variety of ways.<br />

32 Conference Review<br />

<strong>Lubrication</strong> Excellence<br />

Conference Sets Records<br />

Industrial professionals packed the Nashville Convention<br />

Center to attend “Lean, Reliable and Lubed” - the premier<br />

international conference and exhibit for plant management,<br />

maintenance and reliability professionals.<br />

34 <strong>Lubrication</strong> 101<br />

Basic Wear Modes<br />

in Lubricated Systems<br />

This article provides a basic understanding of the major<br />

wear modes or mechanisms of rolling bearings, gears,<br />

journal bearings, hydraulic pumps and pistons.<br />

Editorial Columns<br />

2 As I See It<br />

6 Viewpoint<br />

10 Hydraulics at Work<br />

15 From the Field<br />

Departments<br />

42 Product Ideas<br />

50 Lit Rack<br />

52 Bookstore<br />

54 NLGI Update<br />

56 ICML<br />

58 Back Page Basics<br />

44 Lubricant Application<br />

Improving Oven Chain <strong>Lubrication</strong><br />

Chains operating at high temperatures can be lubricated<br />

in two different ways: with a liquid lubricant, or<br />

with a solid lubricant suspended in a carrier fluid.<br />

Whether solid or liquid, the lubricating film physically<br />

separates contacting metal surfaces, thereby reducing<br />

friction and wear.<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 1


AS I SEE IT<br />

How Water Causes<br />

Bearing Failure<br />

JIM FITCH<br />

Most of us who have spent time in the lubrication field<br />

have been told that it takes only a small amount of<br />

water (less than 500 ppm) to substantially shorten the<br />

service life of rolling element bearings. There is indeed a vast<br />

amount of research that supports these assertions. Being a<br />

career-long crusader of clean and dry oil, I will certainly not<br />

argue the contrary. In fact, water’s destructive effects on<br />

bearings can easily reach or exceed that of particle contamination,<br />

depending on the conditions.<br />

My theme for this column, therefore, is not about whether<br />

water imparts harm but rather how it does. Knowing how<br />

water attacks and causes damage helps in setting important<br />

dryness targets and also aids failure investigations post<br />

mortem. Further, when water contamination is unavoidable,<br />

understanding these water-induced failure modes can be<br />

valuable in the optimum selection of lubricants, bearings and<br />

seals for defensive purposes.<br />

The Scourge of our Machines<br />

There is no contaminant more complex, intense and<br />

confounding than water. The reasons are still being studied, but<br />

they include its various states of co-existence with the oil and its<br />

many chemical and physical transformations imparted during<br />

service. Individually and collectively, moisture-induced problems<br />

exact damage on both the oil and machine and can certainly<br />

lead, either slowly or abruptly, to operational failure of the<br />

bearing. Do not underestimate the attack potential of water.<br />

Water can damage machine surfaces directly, through a<br />

sequence of events and often with a variety of helpers. In<br />

many cases, the most severe damage is the cascading or chain<br />

reaction failure. For instance, water may lead first to premature<br />

oxidation of the base oil. When the oxides combine with<br />

more water, a corrosive acidic fluid environment exists.<br />

Likewise, oxidation can throw-off sludgy insolubles and<br />

increase oil viscosity. Both processes can impede oil flow and<br />

lead to damage of the bearing. Not to be left out, the water and<br />

oxidative environment can hang up air in the oil, amplifying<br />

lubrication problems even further. It’s often true that the worse<br />

things get, the faster they get worse; all started by water.<br />

Failure Modalities<br />

In order to keep this column to a manageable length and<br />

scope, the modalities described below will be brief and to the<br />

point. I’ve left out those that are farfetched or technically<br />

abstract, as well as a couple rooted more in popular lore than<br />

scientific fact. There are even some failure modes on my list<br />

that are largely derived from conjecture, but still believable.<br />

Finally, I’ve made no effort to rank the failure modes in terms<br />

of severity or commonality. My list:<br />

Hydrogen-induced Fractures. Often called hydrogen<br />

embrittlement or blistering, this failure mode is perhaps<br />

more acute and prevalent than most tribologists and bearing<br />

manufacturers are aware. The sources of the hydrogen can be<br />

water, but also electrolysis and corrosion (aided by water).<br />

There is evidence that water is attracted to microscopic<br />

fatigue cracks in balls and rollers by capillary forces. Once in<br />

contact with the free metal within the fissure, the water<br />

breaks down and liberates atomic hydrogen. This causes<br />

further crack propagation and fracture. High tensile-strength<br />

steels are at greatest risk. Sulfur from additives (extreme<br />

pressure (EP), antiwear (AW), etc.), mineral oils and environmental<br />

hydrogen sulfide may accelerate the progress of the<br />

facture. Risk is posed by both soluble and free water.<br />

Corrosion. Rust requires water. Even soluble water can<br />

contribute to rust formation. Water gives acids their greatest<br />

corrosive potential. Etched and pitted surfaces from corrosion<br />

on bearing raceways and rolling elements disrupt the formation<br />

of critical elastohydrodynamic (EHD) oil films that give bearing<br />

lubricants film strength to control contact fatigue and wear.<br />

Static etching and fretting are also accelerated by free water.<br />

Oxidation. Many bearings have only a limited volume of<br />

lubricant and, therefore, just a scintilla of antioxidant. High<br />

2 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


temperatures flanked by metal particles and<br />

water can consume the antioxidants rapidly<br />

and rid the lubricant from the needed oxidative<br />

protective environment. The negative<br />

consequences of oil oxidation are numerous<br />

but include corrosion, sludge, varnish and<br />

impaired oil flow.<br />

Additive Depletion. We’ve mentioned that<br />

water aids in the depletion of antioxidants, but<br />

it also cripples or diminishes the performance<br />

of a host of other additives. These include AW,<br />

EP, rust inhibitors, dispersants, detergents and<br />

demulsifying agents. Water can hydrolyze some<br />

additives, agglomerate others or simply wash<br />

them out of the working fluid into puddles on<br />

sump floors. Sulfur-phosphorous EP additives<br />

in the presence of water can transform into<br />

sulfuric and phosphoric acids, increasing an<br />

oil’s acid number (AN).<br />

Oil Flow Restrictions. Water is highly polar,<br />

and as such, has the interesting ability to mop<br />

up oil impurities that are also polar (oxides,<br />

dead additives, particles, carbon fines and<br />

resin, for instance) to form sludge balls and<br />

emulsions. These amorphous suspensions can<br />

enter critical oil ways, glands and orifices that<br />

feed bearings of lubricating oil. When the<br />

sludge impedes oil flow, the bearing suffers a<br />

starvation condition and failure is imminent.<br />

Additionally, filters are short-lived in oil systems<br />

loaded with suspended sludge. In subfreezing<br />

conditions, free water can form ice crystals<br />

which can interfere with oil flow as well.<br />

Aeration and Foam. Water lowers an oil’s<br />

interfacial tension (IFT), which can cripple its<br />

air-handling ability, leading to aeration and<br />

foam. It takes only about 1,000 ppm water to<br />

turn your bearing sump into a bubble bath. Air<br />

can weaken oil films, increase heat, induce<br />

oxidation, cause cavitation and interfere with<br />

oil flow; all catastrophic to the bearing.<br />

Aeration and foam can also incapacitate the<br />

effectiveness of oil slingers/flingers, ring oilers<br />

and collar oilers.<br />

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SENIOR EDITORS<br />

Jim Fitch - jfitch@noria.com<br />

Drew Troyer - dtroyer@noria.com<br />

Mark Barnes - mbarnes@noria.com<br />

TECHNICAL EDITOR<br />

Jeremy Wright - jwright@noria.com<br />

SENIOR DESIGNER<br />

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MACHINERY LUBRICATION<br />

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VOLUME 8 - NUMBER 4


AS I SEE IT<br />

Impaired Film Strength. Rolling element bearings depend<br />

on an oil’s viscosity to create a critical clearance under load.<br />

If the loads are too great, speeds are too low or the viscosity<br />

is too thin, then the fatigue life of the bearing is shortened.<br />

When small globules of water are pulled into the load zone<br />

the clearance is often lost, resulting in bumping or rubbing of<br />

the opposing surfaces (rolling element and raceway).<br />

Lubricants normally get stiff under load (referred to as their<br />

pressure-viscosity coefficient) which is needed to bear the<br />

working load (often greater than 500,000 psi).<br />

However, water’s viscosity is only one centistoke and this<br />

viscosity remains virtually unchanged, regardless of the load<br />

exerted. It is not good at bearing high-pressure loads. This<br />

results in collapsed film strength followed by fatigue cracks,<br />

pits and spalls. Water can also flash or explode into superheated<br />

steam in bearing load zones, which can sharply<br />

disrupt oil films and potentially fracture surfaces.<br />

Microbial Contamination. Water is a known promoter of<br />

microorganisms such as fungi and bacteria. Over time, these can<br />

form thick biomass suspensions that can plug filters and interfere<br />

with oil flow. Microbial contamination is also corrosive.<br />

Water Washing. When grease is contaminated with water,<br />

it can soften and flow out of the bearing. Water sprays can<br />

also wash the grease directly from the bearing, depending on<br />

the grease thickener and conditions.<br />

The obvious solution to the water problem is a proactive<br />

solution; that is, preventing the intrusion of water into the<br />

oil/grease and bearing environment. The only water that<br />

doesn’t cause harm is the water that doesn’t invade your<br />

system. Contaminant exclusion tactics are always a wise<br />

maintenance investment.<br />

Be a long-term thinker by controlling risk factors today,<br />

while the bearing still has remaining useful life (RUL). The<br />

cost of removing water and/or remediating the damage it<br />

causes will far exceed any investment to exclude it from entry.<br />

So please, don’t skimp when it comes to “proactive” contamination<br />

control.<br />

About the Author<br />

Jim Fitch has a wealth of “in the trenches” experience in lubrication, oil<br />

analysis, tribology and machinery failure investigations. Over the past two<br />

decades, he has presented hundreds of lectures on these subjects. Jim has<br />

published more than 200 technical articles, papers and publications. He serves<br />

as a U.S. delegate to the ISO tribology and oil analysis working group. Since<br />

2002, he has been director and board member of the International Council for<br />

<strong>Machinery</strong> <strong>Lubrication</strong>. He co-founded Noria Corporation in 1997 and<br />

remains an active chairman and senior technical consultant. Contact Jim at<br />

jfitch@noria.com.<br />

4 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


VIEWPOINT<br />

When It Comes to CBM,<br />

Inspect Success<br />

MARK BARNES<br />

Most companies have discovered to some degree the benefits<br />

of condition based maintenance (CBM). By<br />

definition, CBM entails performing maintenance tasks, not on a<br />

scheduled interval basis (such as operating hours, miles, cycles,<br />

etc.) but rather based on data gathered from certain predictive<br />

maintenance tasks such as oil analysis, vibration analysis, thermography<br />

or ultrasonics. The key benefit to a condition-based<br />

maintenance strategy is that maintenance tasks get done only<br />

when required, based on data, optimizing the utilization of<br />

increasingly scarce maintenance resources. Done properly, there<br />

is little doubt that CBM can and does work.<br />

Routine Inspections<br />

While CBM has proved successful for many companies, all<br />

too often they miss the most basic and often the most effective<br />

form of predictive data gathering: routine operator-based<br />

inspections. While some companies struggle, other companies<br />

have jumped in with both feet, anxious to follow the success<br />

of Toyota and others that have successfully deployed<br />

autonomous maintenance in support of lean manufacturing<br />

initiatives. In fact, as many as 43 percent of all U.S.-based<br />

manufacturers are actively pursuing lean maintenance initiatives<br />

with varying degrees of success.<br />

Just like conventional maintenance practices, autonomous<br />

maintenance is predicated on predictive maintenance and, in<br />

particular, routine inspections. These routine inspections are<br />

usually part of regular operator rounds that are performed each<br />

week, day or shift. But even those companies that are having<br />

success with operator-assisted maintenance sometimes miss the<br />

mark; and while their desires are well-intentioned, their execution<br />

of inspections routes is lacking.<br />

From my experience, the main reasons for this are a lack of<br />

detail and engineering design up front in defining what needs<br />

to be inspected, how it should be inspected and documenting<br />

the required inspection routes. Inspections routes<br />

need to be specific. It’s not sufficient to simply state a task<br />

such as “check pump”. For some, check pump may mean to<br />

feel the housing for temperature. Others may look for signs of<br />

a packing leak, while others may simply check yes, indicating<br />

the pump is indeed still in the same place it was yesterday!<br />

Making the List<br />

The best inspection lists include clear, concise, taskspecific<br />

details for each asset. For lubrication, this includes<br />

details such as: check shaft seals for signs of oil leakage and<br />

check oil level gauge for correct operating oil level. Basic<br />

predictive maintenance data should also be collected. This<br />

might include the differential pressure gauge reading across<br />

the filters, the color and clarity of the oil in the sight glass or<br />

the color of the desiccant in the breather.<br />

6 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


VIEWPOINT<br />

Check Yes or No<br />

Wherever possible, questions should be<br />

stated in a simple yes/no format. For example,<br />

“oil appears clean and clear?” with an appropriate<br />

check box for yes or no. Training should<br />

be provided so that operators can easily determine<br />

what cloudy or discolored oil looks like<br />

along with basic tools such as an infrared<br />

temperature gun to measure bearing temperature<br />

or a laser pointer to check for oil clarity.<br />

The inspection routes should be captured<br />

in a simple check sheet format, either electronically<br />

(preferred) or manually. They<br />

should be easily accessible at the machine, but<br />

should also require sign-off to avoid pencilwhipping.<br />

While a simple sign-off process<br />

doesn’t necessarily guarantee that the task<br />

was performed, human nature is such that we<br />

naturally feel more accountable when physically<br />

signing a document or form.<br />

While paper-based inspection routes do<br />

work, all too often, the extra time required to<br />

capture manual route sheets and input into a<br />

tracking spreadsheet or database means that<br />

good intentions often go astray as more<br />

pressing tasks arise. The most successful<br />

inspection routes involve electronic data<br />

collection in the field, using either a rugged,<br />

industrial personal digital assistant (PDA) or<br />

tablet personal computer (PC).<br />

Not only does this offer the advantage that<br />

the information gathered is already databased,<br />

but the PDA or PC can also be used to<br />

include simple drawings or pictures indicating<br />

where inspection points are located and what<br />

normal vs. abnormal conditions look like.<br />

Once databased, a process needs to be put<br />

in place to periodically review the data, and<br />

where necessary, create appropriate maintenance<br />

work orders to correct the problem.<br />

There is no easier way to kill an inspection<br />

program than to send the message that<br />

nobody is looking at the data. In every case<br />

where I’ve seen this happen, the operators<br />

simply stopped performing the inspections.<br />

None of us likes to feel like we’re wasting our<br />

time, and operators are no different.<br />

Multiple Disciplines<br />

Inspections should be cross-disciplinary.<br />

They should include lubrication, mechanical<br />

maintenance, electrical, safety and operational<br />

inspections. It makes little senses to<br />

conduct one survey for lubrication, followed<br />

by a similar survey for electrical systems on the<br />

same machine. If your plant has different<br />

maintenance planners for different maintenance<br />

functions (mechanical, electrical,<br />

production, etc.), inspections can easily be<br />

divided once the information has been gathered.<br />

The critical path is getting good data:<br />

the rest will fall in place accordingly.<br />

When it comes to lubrication, industry<br />

studies reveal that, on average, 30 to 60<br />

percent of all maintenance problems can be<br />

traced to lubrication. It is likely that 70 to 80<br />

percent of those could have been avoided<br />

simply by looking for the correct oil level or<br />

condition, evidence of a seal or breather<br />

failure, or the observation that an automatic<br />

greasing system is not functioning correctly.<br />

Human Resources<br />

Take advantage of the people who are in<br />

front of machines eight to 12 hours a day and<br />

involve operators as part of the solution,<br />

rather than blaming them as part of the<br />

problem.<br />

As always, this is my opinion. I’m interested<br />

in yours.<br />

About the Author<br />

As a skilled educator and consultant in the areas of<br />

oil analysis and machinery lubrication, Mark Barnes has<br />

helped numerous clients develop effective machinery<br />

lubrication programs and troubleshoot complex lubrication<br />

problems through precision lubrication and oil<br />

analysis. As vice president and chief technical officer of<br />

Noria Reliability Solutions, Mark and his group work on<br />

projects in the areas of: plant audits and gap analysis,<br />

machinery lubrication and oil analysis program design,<br />

lube PM rationalization and redesign, lubricant storage<br />

and handling, contamination control system design and<br />

lubrication, and mechanical failure investigations.<br />

Contact Mark at mbarnes@noria.com.<br />

8 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


HYDRAULICS AT WORK<br />

BRENDAN CASEY<br />

Why Your Current<br />

Maintenance Strategy<br />

Is Wrong<br />

We live in a skewed world, where nothing is evenly distributed.<br />

For example, 80 percent of the wealth is held by 20<br />

percent of the population. Eighty percent of your firm’s sales<br />

likely come from 20 percent of its customers. And 80 percent of<br />

your breakdowns are due to 20 percent of the causes.<br />

Pareto’s Law<br />

You may recognize this as the 80/20 principle, or Pareto’s<br />

Law, named after the Italian economist Vilfredo Pareto who<br />

first recognized the pattern in 1897. Pareto was studying the<br />

distribution of wealth in England during the 1800s. Perhaps<br />

not surprisingly, he soon discovered that a minority of the<br />

population held the majority of the wealth. But when he<br />

looked further, Pareto also found the distribution of wealth<br />

was both predictably and consistently skewed, regardless of<br />

which nation or time period he analyzed.<br />

“An 80 percent reduction in your<br />

maintenance costs will likely<br />

come from 20 percent of your<br />

maintenance effort.”<br />

Put simply, Pareto’s Law states an almost universal truth<br />

that nothing is uniformly distributed. The comparative split<br />

between any two sets of variables may not be 80/20. It could<br />

be 95/5, 60/40 or any other variation. But it is unlikely to be<br />

50/50, which represents linear or even distribution.<br />

Pareto’s Law has since been validated in many business applications.<br />

Pareto analysis played a significant role in the quality<br />

revolution, with two of its most notable proponents, W.<br />

Edwards Deming and Joseph Juran, applying it to identify the 20<br />

percent of defects causing 80 percent of the quality problems.<br />

In business sales, it is reasonable to expect that if a firm<br />

has five sales people, the top salesperson will bring in 80<br />

percent of the sales – that’s four times the sales of all the<br />

others put together.<br />

Unequal Effort and Return<br />

Understanding Pareto’s Law can help identify points of<br />

leverage. And the more skewed the distribution, the more<br />

powerful the leverage.<br />

In the sales example above, the sales manager’s natural<br />

inclination is usually to invest time and money to improve the<br />

results of her underperforming sales people, whereas the<br />

principle of unequal effort and return represented by Pareto’s<br />

Law means a better outcome (more sales) will be achieved by<br />

shifting these resources to assisting her star performer.<br />

Similarly, in a maintenance environment, if 95 percent of<br />

your breakdowns were due to five percent of the possible<br />

causes, it follows that if you can identify and eliminate this<br />

small percentage of causes, then you will eliminate 95 percent<br />

of your breakdowns.<br />

As you can see, focusing available resources on identifying<br />

a small percentage of causes provides potential for exponential<br />

gains. Little hinges can swing big doors.<br />

80/20 Maintenance Optimization<br />

In the maintenance and reliability field, we already have a<br />

variety of tools designed to help us allocate resources where<br />

they are needed most. The Reliability-Centered Maintenance<br />

framework, which considers the probability and consequences<br />

of failure, is possibly the most well-known of these.<br />

I’m not promoting 80/20 thinking as a replacement for<br />

these tools, but rather as an addition or enhancement to<br />

them. Consider this example:<br />

During a meeting with a new client, I was briefed on the<br />

hydraulic hose maintenance program for its fleet of hydraulic<br />

10 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


HYDRAULICS AT WORK<br />

mining shovels. This involved changing out every hose on the<br />

machine every 18 months. So whenever a shovel was down<br />

for planned maintenance, a portion of the hoses was<br />

changed out, beginning with the oldest first.<br />

The hydraulic hose supplier who devised the program was<br />

somewhat of a hero because, prior to its implementation,<br />

improvised hose replacement in response to in-service failures<br />

had resulted in machine availability falling to as low as<br />

65 percent.<br />

When a multimillion-dollar shovel stops, so does a multimillion-dollar<br />

fleet of haul trucks. So downtime is a major cost. But<br />

large-diameter, multispiral, hydraulic hoses aren’t cheap either.<br />

Not All Hoses Are Equal<br />

I couldn’t argue with the success of the hose replacement<br />

program; however, I did point out its fundamental flaw. It<br />

treated all hoses equally. The 80/20 principle suggests it<br />

would be highly unlikely that 50 percent of the hoses were<br />

responsible for 50 percent of the in-service failures and<br />

downtime.<br />

So I explained to my client if he were to look at the historical<br />

data, he should expect to see a skewed picture: that 20<br />

percent of the hoses were causing 80 percent of the in-service<br />

failures and downtime.<br />

In fact, the available data revealed less than 20 percent of<br />

the hoses were responsible for nearly 90 percent of the failures<br />

(note that we are comparing two sets of unique data, so<br />

the comparative split doesn’t have to add up to 100).<br />

This discovery not only reduced my client’s hose bill (oils<br />

spills, ingression of air and other contaminants), but the risk<br />

associated with the introduction of human agents as a result<br />

of unnecessary hose replacement was eliminated as well.<br />

Conclusion<br />

As this story illustrates, if you are applying linear thinking<br />

to any facet of your maintenance strategy, it’s wrong. An 80<br />

percent reduction in your maintenance costs will likely come<br />

from 20 percent of your maintenance effort. The trick is in<br />

identifying the significant 20 percent.<br />

About the Author<br />

Brendan Casey has more than 19 years experience in the maintenance,<br />

repair and overhaul of mobile and industrial hydraulic equipment. For more<br />

information on reducing the operating cost and increasing the uptime of your<br />

hydraulic equipment, visit his Web site: www.InsiderSecretsToHydraulics.com.<br />

12 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


FROM THE FIELD<br />

How Effective Is Your<br />

<strong>Lubrication</strong> Program?<br />

JARROD POTTEIGER<br />

The path to lubrication excellence can be difficult to navigate.<br />

It begins when individuals and organizations<br />

become aware of the importance of their lubrication<br />

program, its impact on productivity and its direct effect on<br />

the bottom line. Once this enlightenment has occurred,<br />

comprehensive training in best practices is acquired and the<br />

organization can consider what the lubrication program<br />

should be and where they wish to take it.<br />

However, to get to Point B, Point A must first be determined.<br />

Even if the goals and objectives are defined, be they broad or<br />

narrow in scope, they can be difficult to reach. With the goals<br />

identified, a step-wise strategy must be developed. The first step<br />

is to assess the current situation. After all, the best map in the<br />

world is useless if you’re not properly oriented.<br />

To determine the current state of a lubrication program, a<br />

rigorous assessment should be performed. This assessment<br />

can be broken down into 12 key components which, when<br />

properly analyzed, can identify areas of weakness and opportunity<br />

as well as the strengths of the program. Each of the 12<br />

categories is comprised of a series of objective criteria scored<br />

on a scale of zero to 10.<br />

The composite score for each category is calculated and<br />

plotted on a two-dimensional diagram with 12 axes, called a<br />

spider diagram. The spider diagram, so named for its weblike<br />

appearance, can be a powerful visual tool to indicate the<br />

overall state of the program as well as identify the individual<br />

areas of opportunity.<br />

The 12 Components of the Audit<br />

1. Standards, Consolidation and Procurement<br />

More often than not, opportunities exist to consolidate<br />

and eliminate many of the lubricants utilized in a plant. The<br />

benefits of safely and effectively reducing the number of<br />

products used are many. Standards should exist not only to<br />

consolidate lubricants, but to select them, procure them and<br />

assure product quality.<br />

Effective communication among management, purchasing,<br />

maintenance and engineering is imperative for success in this<br />

area. To identify opportunities for consolidation, all of the lubricants<br />

used in a facility should be converted to a generic<br />

classification, such as R&O ISO 46. If several products fit the<br />

same generic specification, it is likely that some of the product<br />

could be eliminated.<br />

2. Storage and Handling<br />

To extract the maximum value from lubricants and the<br />

lubrication program, lubricants must be properly managed<br />

from cradle to grave. This means adopting best practices for<br />

receiving, storing, dispensing, maintaining and finally<br />

disposing of used lubricants. The lube store room design,<br />

dispensing equipment and handling procedures should be<br />

assessed and improved where necessary. The useful life and<br />

Program<br />

Goals/<br />

Metrics<br />

Best Practice<br />

Continuous Improvement<br />

Safety<br />

Practices<br />

Procedures/<br />

Guidelines<br />

Program Management<br />

Standards, Consolidation,<br />

and Procurement<br />

10.0<br />

8.0<br />

6.0<br />

4.0<br />

2.0<br />

0.0 00<br />

<strong>Lubrication</strong>/Relubrication Practices<br />

Figure 1. Spider Diagram<br />

Typical Program<br />

Storage/Handling<br />

Lubricant Analysis<br />

Sampling<br />

Techniques<br />

Contamination<br />

Control<br />

Training,<br />

Skill Standards,<br />

Certification<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 15


FROM THE FIELD<br />

the quality of lubricants depend greatly on the way the products<br />

are managed before being applied to the machinery.<br />

3. Sampling Techniques<br />

One key to an effective oil analysis program is to collect<br />

valid data. It is all too common for used oil samples to be<br />

taken in a haphazard manner, using substandard equipment<br />

and procedures. Ineffective sampling techniques can produce<br />

erroneous results, severely diminishing or even eliminating<br />

their value. Worse still, invalid results can lead to poor decisions,<br />

adding to the waste of resources. A productive oil<br />

analysis program requires correct sampling procedures,<br />

sampling hardware, sample point location, and properly<br />

trained and qualified technicians.<br />

4. Contamination Control<br />

Contamination control is possibly the single greatest<br />

opportunity for the average lubrication program. It is<br />

common to see significant gains in lubricant cleanliness,<br />

which is directly related to machinery reliability, with minimal<br />

investment. Proper selection, installation and maintenance of<br />

breathers, filters, gaskets and seals can curtail or eliminate<br />

solid particle and water contamination. Methods should also<br />

be available to remediate contaminated systems and to effectively<br />

monitor contamination levels.<br />

5. Education, Training and Skills Management<br />

An educated workforce is a powerful asset to any organization.<br />

For the lubrication program to succeed, there must be<br />

awareness, cooperation and desire for success at every level.<br />

Skill sets and competency levels must be defined for all who<br />

affect the program. Employees should be encouraged to<br />

improve their knowledge in all areas by pursuing ongoing<br />

training with opportunities and rewards for successfully<br />

achieving professional certifications.<br />

6. Oil Analysis<br />

A properly designed and managed oil analysis program is<br />

one of the best investments that can be made for machine<br />

reliability. Oil analysis is the perfect tool for proactively monitoring<br />

machine condition to ensure that proper lubrication<br />

conditions exist. Oil analysis also allows for the optimization<br />

of drain intervals, thereby increasing the efficiency of the<br />

lubrication program.<br />

It is also an excellent tool for detecting incipient failures,<br />

often in advance of other condition monitoring technologies.<br />

To be effective, test slates must be defined for all sampled<br />

equipment including normal and exception tests. Other items<br />

to be evaluated are data management, test intervals,<br />

appropriate targets and limits, quality assurance for lab<br />

methods, and integration with other technologies.<br />

7. <strong>Lubrication</strong> and Relubrication Practices<br />

The methods by which lubricants are selected and applied<br />

to machinery can be more important than the lubricants<br />

themselves. Many organizations go out of their way to<br />

purchase more expensive lubricants to achieve greater equipment<br />

reliability while ignoring poor lubrication practices that<br />

contribute more heavily to equipment failure. It is essential<br />

that methods be established and documented, based on<br />

accepted best practices, for applying lubricants to machinery<br />

in a consistent manner which fosters equipment reliability.<br />

8. Program Management<br />

Numerous individuals and groups affect the lubrication<br />

program. Management, operations, engineering and maintenance<br />

personnel all play a vital role. Effective and frequent<br />

communication between these groups is a key ingredient for the<br />

program’s success. Clearly defined goals and objectives should<br />

be developed and periodically reviewed to track performance<br />

and to shift focus when necessary. It is helpful to devise a set of<br />

metrics which can be charted and publicly displayed so that<br />

everyone involved can see the progress and share the credit.<br />

9. Procedures and Guidelines<br />

It makes sense that all lubrication-related tasks be<br />

performed in a consistent manner that conforms to best<br />

practices. It is not enough to provide training to the technicians<br />

responsible for performing the tasks. To ensure<br />

adherence to best practice techniques, procedures must be<br />

developed and documented in a step-by-step fashion so that<br />

any individual who may be called upon to perform a task can<br />

do so without compromising quality. Ideally, each procedure<br />

would be the responsibility of one person.<br />

However, due to personnel changes, vacations and other<br />

unforeseen circumstances, it is likely that a single task may be<br />

performed by many individuals with different backgrounds or<br />

skill levels. Additionally, the procedures should be readily<br />

available, preferably in an electronic format which can be<br />

attached to work orders generated by the CMMS system.<br />

10. Goals and Metrics<br />

Once the goals have been established and the course laid out,<br />

there is a need for yardsticks by which to measure the progress<br />

of the various aspects of the program. Performance metrics<br />

should be identified to assess the degree to which improvements<br />

have been completed and to measure the overall effectiveness of<br />

the lubrication program. These metrics should show the value<br />

16 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


obtained from advances in the program, which will keep<br />

everyone focused and provide justification for continued<br />

improvement. Having defined action plans for unmet goals will<br />

facilitate the success of the program.<br />

11. Safety Practices<br />

It goes without saying that safety is the top concern for any<br />

industrial facility. Many initiatives designed to improve<br />

machinery reliability can actually contribute to<br />

improved safety as well. Leak remediation,<br />

proper handling of materials, spill controls and<br />

drain interval optimization can potentially<br />

reduce the frequency of occurrence of lubricant<br />

related-accidents. Proper training for the<br />

potential hazards associated with the handling<br />

of lubricants can further reduce health risks.<br />

About the Author<br />

Jarrod Potteiger is a leading consultant and trainer for Noria Reliability<br />

Solutions. As technical services director, he has helped pioneer Noria’s<br />

world-class <strong>Lubrication</strong> Process Design (LPD) and other services. He has<br />

also provided training and mentorship to other consultants and helped<br />

to construct a design team which provides the highest level of service in<br />

our industry.<br />

He has trained hundreds of maintenance and reliability professionals in<br />

Noria’s public and on-site seminars and has presented at a variety of technical<br />

conferences. Contact Jarrod at jpotteiger@noria.com.<br />

12. Continuous Improvement<br />

Success is a journey, not a destination. Even<br />

if a lubrication program was perfectly designed<br />

and implemented, it would still require changes<br />

from time to time. Changing conditions such<br />

as production demands, new equipment and<br />

new technologies require some aspects of the<br />

program to undergo continuous improvement.<br />

Methods should be in place to perform root<br />

cause analysis on machine failures not<br />

predicted by oil analysis as well as recurring<br />

premature failures. Recurring failures should<br />

be addressed by considering alternate lubricants<br />

or machine design modifications to<br />

eliminate or resist the suspected root cause.<br />

Defining an action plan to achieve excellence<br />

in a lubrication program can be a<br />

daunting task and requires an initial survey<br />

to gain perspective. Some organizations may<br />

have the desire and qualified personnel to<br />

perform such an audit, while others may hire<br />

outside consultants.<br />

The spider diagram is a valuable tool for<br />

assessing and visually representing the<br />

current state of the program. When scaled<br />

with an appropriate weighting system, it can<br />

indicate the primary areas of focus for<br />

resource allocation. After the initial assessment,<br />

this method can be used for<br />

subsequent evaluations which will indicate<br />

the effectiveness of the current strategies and<br />

highlight the deficiencies.<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 17


CONTAMINATION CONTROL<br />

A New Option for Keeping Your<br />

Hydraulic Systems Clean<br />

BY ROB PROFILET, THE LUBRIZOL CORPORATION<br />

Hydraulic equipment users routinely change or clean servo<br />

valves. But is that practice really necessary? What are the<br />

cost implications? Are there alternatives?<br />

Often, valves are changed because they are stuck in one<br />

position or do not respond properly to commands. When the<br />

system no longer operates effectively, the only choice is to<br />

stop the machine and replace the valve. Unfortunately,<br />

changing valves is the norm in some operations, and this<br />

expense is rolled into the overall cost.<br />

An electrostatic filtration system is one way to remove<br />

contaminants that affect hydraulic system efficiency.<br />

Electrostatic filters require physical space in your plant and<br />

may not be the optimum solution, depending on the condition<br />

of your fluid.<br />

This shows a varnish-laden sump. If varnish is present in the<br />

sump, it is also present in other places in the system.<br />

Clean Sump<br />

Challenges for Hydraulic Oils<br />

Original equipment manufacturers report that the most<br />

frequent problems with higher-performance hydraulic systems are:<br />

1. Systems are getting smaller while the flow rates in the reservoir<br />

have decreased.<br />

2. The reservoir size and shape are not optimum for fluid life.<br />

3. Oil flow rates are high compared to oil volumes.<br />

4. Hydraulic systems are designed to have higher power densities.<br />

5. Oil temperatures are higher.<br />

6. Oil pressures have increased in general.<br />

Consequences of<br />

Those Challenges<br />

1. Foaming and cavitation occur because oil spends insufficient<br />

time in the reservoir for air to release and foam to collapse.<br />

2. Shorter fluid lifespan due to increased oxidation.<br />

3. Poor hydraulic valve response due to sludge and varnish<br />

buildup.<br />

4. Greater need to replace blocked filters.<br />

5. Increased valve and pump wear.<br />

18 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


There is another solution: New additive technology for<br />

hydraulic oil can reduce the need to frequently clean or<br />

change the servo valves. Such technology works to prevent<br />

varnish from depositing on critical work surfaces. The result<br />

is longer component life and a hydraulic system that stays<br />

clean. That translates into improved equipment efficiency<br />

and reduced cost.<br />

A major use for industrial lubricants is in hydraulic equipment,<br />

and varnish formation is a major issue<br />

for many of these applications.<br />

is most obvious at low pressures when there is little<br />

centrifugal force and low fluid pressure.<br />

In the case of piston pumps, varnish can increase piston<br />

land friction against the wear plate, leading to leakage and<br />

possible seizure. It also is well known that sticking valves,<br />

such as the regulation valves on piston pumps, can cause<br />

unscheduled stoppages during equipment use. Finally, the<br />

varnish that forms can block filters, leading to high use of<br />

Varnish Defined<br />

As oil ages, it degrades through oxidation<br />

and thermal decomposition. The additives,<br />

which are performance-enhancing chemicals,<br />

are consumed during the life of the<br />

fluid. The decomposition by-products of<br />

aging increase over the life of the oil, ultimately<br />

forming varnish.<br />

Because varnish is polar, it is attracted to<br />

metal surfaces, including servo valves. It<br />

starts as a sticky, soft residue and attracts<br />

wear debris, forming a sandpaper-like<br />

surface. In time, it ends up as a tenacious,<br />

hard lacquer.<br />

Why It’s Bad<br />

Oil that has oxidized generally does not<br />

lubricate well. It can reduce oil flow, plug<br />

filters, cause valves (especially proportional<br />

and servo types) to stick, increase friction,<br />

inhibit heat transfer and elevate operating<br />

temperature. Because varnish acts as an<br />

insulator, cooling capacity can be diminished.<br />

In addition, oxidation shortens<br />

component life, affecting valves, filters,<br />

pumps, bearings and seals. The result is<br />

diminished hydraulic system performance.<br />

For example, when varnish adheres to<br />

vanes in high-performance vane pumps, the<br />

vanes can stick in the rotor slot. This can<br />

result in increased noise, decreased volumetric<br />

and mechanical efficiency with an<br />

equivalent increase in energy consumption,<br />

side plate scuffing, rotary seal damage and<br />

possibly bearing damage. The phenomenon<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 19


CONTAMINATION CONTROL<br />

filter cartridges and increased maintenance<br />

costs.<br />

Expenses of Varnish<br />

Having to change or clean hydraulic<br />

system servo valves and risk system failure<br />

are some of the results of varnish. A new<br />

servo valve can cost $3,000, and approximately<br />

$2,000 to clean and refurbish. But<br />

the expense doesn’t end there. Don’t forget<br />

the associated labor and shutdown costs,<br />

both of which impact your bottom line.<br />

And if the system fails, your income<br />

declines as well.<br />

Let’s put that into real-world terms in the<br />

following example: A large plastic injection<br />

molding company produces between 20<br />

million and 30 million parts per month with<br />

more than 200 machines that range from 33<br />

to 770 tons. The hydraulic fluid reservoirs in<br />

these machines range from 80 to 250<br />

gallons. The equipment operates 24 hours a<br />

day, five days a week. Excluding lost production,<br />

the estimate of the yearly cost due to<br />

varnish is approximately $135,000.<br />

In addition to potentially triggering<br />

premature replacement of control valves, if<br />

left uncorrected, varnish can reduce filter<br />

load-carrying capacity and plug supplemental<br />

cooling system orifices.<br />

Solution to Varnish<br />

In the past, equipment users replaced<br />

servo valves or cleaned them as needed to<br />

keep their systems operating. Electrostatic<br />

filters and precipitators have been used<br />

successfully but have some shortfalls,<br />

including their cost and the loss of productive<br />

floor space in the plant.<br />

The ideal solution is to use hydraulic<br />

fluid that does not allow varnish to deposit<br />

on metal surfaces while it provides important<br />

wear and corrosion prevention and<br />

water separation capabilities. Because<br />

hydraulic formulations are carefully<br />

balanced to meet OEM requirements,<br />

adding a new varnish-mitigating feature to<br />

the fluid’s performance profile requires a<br />

unique solution.<br />

Fluids are now available that incorporate<br />

additive chemistry that reacts with the<br />

precursors to varnish, minimizing the formation<br />

of resinous films on system hardware.<br />

This technology recently achieved Denison<br />

HF-0-approval.<br />

Laboratory testing demonstrates the<br />

clean feature offered by these new fluids. In<br />

industry-accepted pump tests, many widely<br />

used fluids show varnish formation within<br />

500 hours of beginning operation. Compare<br />

that to the results found in the new additive<br />

technology solution to the age-old varnish<br />

problem: Even after 1,000 hours of use,<br />

there is no evidence of varnish formation.<br />

Industrial hydraulic systems typically<br />

operate at approximately 140°F, although<br />

temperature spikes up to 180°F are<br />

common. High-temperature applications<br />

that place thermal stresses on the oil - such<br />

as plastic injection molding machines, glass<br />

transfer systems, heavy presses and mobile<br />

equipment - are ideal candidates for this<br />

new technology. It also is a good choice if<br />

you want to improve the productivity of<br />

your equipment and extend the life of oil,<br />

equipment and components such as valves,<br />

filters and pumps.<br />

Today’s hydraulic fluids are subjected to<br />

increasingly tough operating conditions.<br />

Demands to increase production at the<br />

same time that oil volume is decreasing<br />

emphasize the importance of using highquality<br />

hydraulic fluids. Increased<br />

operating temperatures have resulted in<br />

today’s hydraulic systems developing<br />

varnish deposits over time that can lead to<br />

problems. The availability of new additive<br />

chemistries goes hand-in-hand with today’s<br />

harsher operating conditions.<br />

About the Author<br />

Rob Profilet is the commercial manager for industrial<br />

hydraulic and gear oils with the The Lubrizol<br />

Corporation. For more information, visit<br />

www.lubrizol.com.<br />

20 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


CASE STUDY<br />

Storage and Dispensing<br />

Systems Complement Lube<br />

Room Procedure<br />

BY LARRY KING, THE IFH GROUP, INC.<br />

Beaver Valley Power Station (BVPS) is a nuclear power<br />

plant near Shippingport, Pa., 34 miles from Pittsburgh.<br />

The plant has two Westinghouse pressurized water reactors<br />

capable of producing 970 and 920 megawatts of power,<br />

respectively. It is owned by First Energy Nuclear Operating<br />

Corporation. Unit 1 has been in commercial operation since<br />

1976, and Unit 2 commenced commercial operation in<br />

<strong>August</strong> 1987.<br />

Figure 1. A 24-container System<br />

The plant’s location on the Ohio River has the historic<br />

significance of being on the site of the United States’ first<br />

nuclear power plant, which went into service on December 2,<br />

1957. It generated 60 megawatts of electricity at full power,<br />

according to Tyrone Turner, supervisor of the tool room and<br />

metrology lab at BVPS.<br />

In a modern, large-scale facility such as BVPS, there is large<br />

amount of machinery (such as turbines, diesel generators<br />

and a vast array of pumps), all of which require lubrication.<br />

“Every pump and gear case in the plant requires its own<br />

lubricant,” said tool room attendant Ted Kubera.<br />

Now in his 30th year with BVPS, Kubera is in charge of the<br />

daily operation of the oil room, located within the tool room<br />

area at the plant. Because security is a priority, access to this<br />

secure room is restricted.<br />

“The tool room is always locked when unoccupied,”<br />

Kubera said. And because the oil room is located within the<br />

heated tool room, the oil is not only secure, but is also warm<br />

and ready to use.<br />

Making sure that every piece of machinery in the plant<br />

receives the right lubricant is critical, and it’s important that<br />

the oil is fresh, clean and free of contaminants. A variety of<br />

premium-performance circulating lubricant oils of different<br />

grades and weights are stored in a custom-designed fluid<br />

storage and dispensing system manufactured by The IFH<br />

Group, Inc. of Rock Falls, Ill. The system was sold to BVPS by<br />

M.W. Byers Company in Carnegie, Pa., which helped BVPS<br />

custom design the system and install it in 2001.<br />

Before<br />

The lubricants are delivered in 55-gallon drums wheeled<br />

into the oil room. Before installation of the IFH system, the<br />

lubricants had been dispensed from 55-gallon drums with<br />

spouts mounted on racks. The drums had to be laboriously<br />

hauled up onto the racks and dispensed from the drums and,<br />

22 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


CASE STUDY<br />

according to Kubera, “It wasn’t filtered. Oil drums were reused<br />

by the manufacturer and could contain contaminants.”<br />

After<br />

Now, the 55-gallon drums are delivered into the oil room<br />

and the oil is pumped into the containers in the storage and<br />

dispensing system, which is arranged in two rows, one on top<br />

of the other, of 12 containers each (Figure 1). Each of the 24<br />

lightweight 65-gallon capacity aluminized steel containers<br />

holds a different oil, and is clearly labeled with the name and<br />

grade of the product.<br />

The 10 gallons of additional capacity that each container<br />

holds enables all of the product to be pumped out of the 55-<br />

gallon drums and into the system. Each container also has a<br />

Figure 2. Quick-coupling Filter Assembly<br />

sight gauge that clearly shows the level of lubricant in it. This<br />

feature makes inventory control easier and eliminates the<br />

need to have extra product standing by.<br />

“The container system was easy to put up,” Kubera said. “The<br />

dispensing manifold, drip pan, pump, motor and timer came<br />

preassembled and tested from the factory, and we were able to<br />

assemble and install it fairly quickly. It has made pumping<br />

product a lot easier, and it has a nice, clean, orderly appearance.”<br />

No Cross-contamination<br />

A key reason for the installation of the system was to<br />

prevent cross-contamination. A product is filtered as it is<br />

pumped into the numbered containers by the quick-coupling<br />

filter assembly through a corresponding numbered valve<br />

arrangement underneath the containers (Figure 2). This<br />

helps to ensure that the lubricant the technician is getting is<br />

exactly what has been requested.<br />

Drip pans contain all spills. In place of the standard<br />

screened vents, each row of tanks has the vent fittings piped<br />

to a Des-Case desiccant breather installed on the side of the<br />

container system, one per row. This way, whatever contaminants<br />

that may be in the ambient air (especially moisture) are<br />

not drawn into the containers when the oil is discharged. This<br />

ensures that the air entering the containers is always clean.<br />

“Cross-contamination from one type of oil to another is one<br />

of the biggest problems,” Kubera said. “We ensure that no two<br />

different oils from different families ever touch each other.” With<br />

this system in place, the oil is filtered at three microns.<br />

The plant prides itself on the detailed procedures it has in<br />

place to make sure the wrong lubricant is never dispensed.<br />

Electronic Lube Manual<br />

“We created a comprehensive Electronic Lube Manual<br />

(ELM) that ensures procedures are followed down to the last<br />

Figure 3. Container with MSDS Label<br />

Figure 4. Poly Containers<br />

24 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


detail,” Kubera said. “Before we issue any oil, we have to see<br />

a work order that shows what system the requested lubricant<br />

is for. Every component has an asset number; this process<br />

requires the technician requesting any lubrication to have<br />

documentation. The ELM database uses the asset number to<br />

identify all approved lubrications for that component. We<br />

then look up the asset number using the ELM, which tells us<br />

exactly what type of oil is needed for that component. Using<br />

the ELM ensures that the correct lubrication<br />

matches the lubricant requested.”<br />

Prior to leaving the issue point, a Material<br />

Safety Data Sheet (MSDS) label containing the<br />

product name, grade (heavy, medium, light,<br />

etc.), the manufacturer, chemical makeup and<br />

combustibility rating is printed. In addition,<br />

the MSDS information addresses any restrictions<br />

(Figure 3).<br />

55-gallon barrels. All oily waste by-products are disposed in<br />

specially marked bags and then removed from the tool room.<br />

Beaver Valley’s process for the storage and dispensing of<br />

lubricants has made it a model plant that First Energy plans<br />

to initiate in its other plants.<br />

About the Author<br />

Larry King is Midwest regional sales manager for The IFH Group, Inc. To<br />

learn more, visit www.ifhgroup.com.<br />

Peer Check<br />

“During lubricant dispensing, we use a<br />

two-person peer check process,” Kubera<br />

said. “We check the name of the oil and the<br />

label on the container and the dispensing<br />

valve, then a second person performs the<br />

same checks to ensure we have the right<br />

spout. When the technician and the tool<br />

room attendant leave the oil room, I know<br />

we have the right oil, and that it’s clean and<br />

not cross-contaminated with any other oil or<br />

other potential contaminants. We never<br />

reuse containers or funnels. We use new<br />

containers for dispensing oil to ensure cleanliness<br />

and eliminate cross-contamination.”<br />

The 24-container system is used for everyday<br />

oils, Kubera said. For less frequently used lubricants,<br />

the plant installed a 10-container system<br />

in 2006 that employs 15-gallon capacity<br />

containers made of polyethylene (Figure 4).<br />

For seldom-used oils not stored in the IFH<br />

containers, Kubera devised a security tag<br />

that is placed on the 55-gallon drums in<br />

which they are stored. No one can help<br />

themselves to the contents of any of these<br />

drums without breaking the seal; therefore,<br />

this process ensures positive control.<br />

Waste oil is stored in flammable waste cabinets<br />

located within the tool room outside the<br />

oil room. Each waste container contains two<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 25


CONTAMINATION CONTROL<br />

Managing Water<br />

Contamination to Maintain<br />

Effective Steel Mill <strong>Lubrication</strong><br />

BY GREGORY J. SEDELMEIER, SHELL GLOBAL SOLUTIONS (U.S.) INC.<br />

Moisture is omnipresent in steel mills. It comes primarily<br />

from mill cooling water entering the circulating oil<br />

system and from simple condensation during mill downtime.<br />

Although necessary to reduce the extreme heat generated in<br />

the processing of steel, water is among the most destructive<br />

contaminants to the circulating oil system. Water can<br />

degrade a lubricant in a variety of ways, including dissolution<br />

of the water into the oil, the formation of emulsions or simply<br />

the presence of free water.<br />

First and foremost, rust occurs when water attacks steel or<br />

metal surfaces, and this leads to the formation of iron oxide.<br />

Corrosion differs from rust because it occurs when metal<br />

surfaces are attacked by acids. Regardless, whether by rust or<br />

corrosion or both, the end result is the same: damage to the<br />

metal surface. In addition, rust and corrosion prematurely<br />

degrade the lubricant performance unless steps are taken to<br />

minimize the conditions that promote them and a quality<br />

lubricant is selected to ensure long life.<br />

All kinds of critical mechanical parts in the steel mill are<br />

susceptible to water contamination. These parts include roll<br />

necks, journals and roller bearings. Therefore, it is important to<br />

use lubricants that can effectively handle wet environments and<br />

resist quick degradation of quality due to the formation of emulsions,<br />

accelerated oxidation and other factors.<br />

Emulsions<br />

The rolls in the hot-strip mill may be subjected to thousands of<br />

gallons of water every minute, so the bearings can take in significant<br />

amounts of water constantly. The churning of the oil and<br />

water through the bearings can create a milky-looking substance<br />

called an emulsion. An emulsion is a mixture of insoluble liquids<br />

in which one is dispersed in droplets throughout the other.<br />

In mill operations, once an emulsion forms, it is often<br />

difficult to break. Emulsion forming in the lubricating system<br />

will cause the circulating oil to lose its ability to lubricate<br />

effectively, which can result in rusting, oxidation, corrosion<br />

and a general degradation of the bearing life.<br />

Four key elements are necessary to form an emulsion: oil,<br />

water, agitation and an emulsifying agent. Agitation is necessary<br />

to shear the water into small enough droplets that could<br />

get dispersed into the oil phase. The emulsifying agent is a<br />

component that serves to stabilize the emulsion, and is<br />

usually present in small concentrations. It is soluble in the oil<br />

phase and it concentrates itself at the oil-water interface,<br />

26 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


CONTAMINATION CONTROL<br />

forming a barrier preventing the water drops from uniting<br />

and subsequently breaking the emulsion.<br />

There are many materials that could act as emulsifying<br />

agents. Some examples of emulsifying agents include<br />

asphaltines (high molecular weight chemicals containing<br />

metals, sulfur, nitrogen and/or oxygen), phenols (and other<br />

cyclic alcohols), resins, and corrosion and contamination<br />

products such as silt, clays, sulfides and calcium by-products.<br />

Besides the formation of emulsions, other key consequences<br />

of water contamination in the steel mill include the following:<br />

• The restriction of the circulation of the oil<br />

• A reduction in the effectiveness of the filtration system<br />

• Promotion of sludge formation<br />

• Increased oxidation<br />

• Reduction of the oil viscosity and its film-forming properties<br />

(loss of film strength)<br />

• Increased possibility of bacterial growth<br />

• Increased foaming and air entrainment<br />

• Promotion of rusting and corrosion<br />

• Possible cause of some additive precipitation or destabilization<br />

(ZDDP)<br />

• Displacement of polar additives at metal surfaces<br />

The ultimate result of severe or prolonged water contamination<br />

of steel mill lubricants is excessive wear and early<br />

failure of various metal parts, especially the critical bearings<br />

necessary to keep production moving. There is much that the<br />

maintenance department in a steel mill can do to reduce the<br />

extent of water contamination, but because the presence of<br />

water is unavoidable, an effective lubricant must be able to<br />

show resiliency to excessive water. In other words, the oil<br />

must have good demulsibility properties.<br />

Demulsibility<br />

Demulsibility is a property of an oil to separate from water<br />

and resist the formation of emulsions. Ability of an oil to<br />

resist the formation of emulsions in service is the best<br />

measure of demulsibility rather than initial resistance to<br />

water. The oil will perform best if the water content is consistently<br />

kept below 0.5 percent.<br />

Factors that determine the demulsibility of an oil include<br />

the base stocks and additives used in manufacture, along<br />

with the presence of contaminants. Among these factors,<br />

though, the additives used to formulate a particular oil can<br />

have a great affect on how well the lubricant ultimately<br />

performs in a wet environment.<br />

Demulsibility additives (known as demulsifiers) within a<br />

lubricating oil act to break emulsions and promote water<br />

separation in two main ways. First, demulsifiers promote the<br />

Property Method ISO 100 ISO 150 ISO 220 ISO 320 ISO 460 ISO 680<br />

Viscosity at 40°C, cSt ASTM D 445 90-110 135-165 198-242 288-352 414-506 612-748<br />

Viscosity Index ASTM D 2270 90 min. 90 min. 90 min. 90 min. 90 min. 85 min.<br />

Low Temperature Demulsibility ASTM D 2711<br />

Non-EP Method at 125°F<br />

(Modified)<br />

Free water before Centrifugation, mL 30 30 30 30 26 26<br />

Water in Oil, percent Report Report Report Report Report Report<br />

Maximum Emulsion, mL 1.0 1.0 1.0 1.0 1.0 1.0<br />

Dynamic Demulsibility Endurance Test<br />

Clark Labs<br />

Maximum Water in Oil after Centrifuging, percent 10 10 10 10 10 15<br />

Maximum Oil in Water after Centrifuging, percent 1 1 1 1 1 1<br />

Rust Protection ASTM D 665A Pass Pass Pass Pass Pass Pass<br />

Rust Protection ASTM D 665B Optional Optional Optional Optional Optional Optional<br />

Pour Point, °C ASTM D 97 -6 -6 -6 -6 0 0<br />

Flash Point, °C ASTM D 92 195 195 195 195 195 195<br />

Oxidation Resistance, min ASTM 2272 80 80 80 80 80 80<br />

Foaming Characteristics ASTM D 892<br />

Sequence I, mL/mL 50 / 0 50 / 0 50 / 0 50 / 0 50 / 0 50 / 0<br />

Sequence II, mL/mL 50 / 0 50 / 0 50 / 0 50 / 0 50 / 0 50 / 0<br />

Sequence III, mL/mL 50 / 0 50 / 0 50 / 0 50 / 0 50 / 0 50 / 0<br />

Yellow Metals Corrosion ASTM D 130<br />

3 hours at 100°C, Rating 1.0 max. 1.0 max. 1.0 max. 1.0 max. 1.0 max. 1.0 max.<br />

Neutralization Number ASTM D 974 Report Report Report Report Report Report<br />

Table 1. MORGOIL Advanced Lubricant New Oil Specifications (Revision 2.3, March 2004)<br />

28 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


formation of water droplets into a greater mass (as in a<br />

suspension) by creating a chemical bridge between the water<br />

droplets. The next part of the process of demulsification is<br />

coalescence of the water droplets.<br />

When the chemical bridge has been formed, the demulsibility<br />

additive acts to break the emulsion film and replace the emulsified<br />

water molecules to form an unstable film. The demulsifiers<br />

may also penetrate the emulsion to form a path through which<br />

water drains from one droplet to the other.<br />

This mechanism will allow the smaller water<br />

droplets to coalesce into bigger droplets and<br />

migrate to the bottom of an oil tank, where<br />

they may be drained off.<br />

Sulfonates, amines, fatty oils and acids, phosphates and<br />

oxidized wax acids are among the chemicals used as RI. The oil<br />

film formed by RI oils assists in the repulsion of water.<br />

Demulsifiers<br />

Demulsifiers (as discussed previously) act as water<br />

repellants and barriers to water entry (into the lubricant/circulating<br />

oil system).<br />

Effective <strong>Lubrication</strong><br />

for Wet Environments<br />

Considering the potentially devastating<br />

effects of water, a lubricant that separates out<br />

water quickly and efficiently must be chosen.<br />

Complementing lubricants that promote good<br />

demulsibility, rust-inhibited oils counteract the<br />

potential rusting of roll necks, journals and<br />

roller bearings mainly through the action of<br />

specially formulated additives.<br />

Important additives that are usually<br />

contained in effective rust-inhibited oils include<br />

oxidation inhibitors (OI), rust inhibitors (RI)<br />

and corrosion inhibitors. These oils are<br />

commonly known as R&O oils. Quality R&O<br />

oils are typically characterized as containing<br />

many, if not all, of the following additives:<br />

Oxidation Inhibitors<br />

Oxidation inhibitors block the formation<br />

of corrosive acids. In addition, OI are used<br />

to prevent oil thickening and the formation<br />

of varnish and sludge due to the oxidation of<br />

the oil. OI terminate oil oxidation reactions<br />

by forming inactive soluble compounds or by<br />

taking up oxygen. Organic compounds<br />

containing sulfur, phosphorus and nitrogen<br />

are commonly used as OI.<br />

Rust Inhibitors<br />

Rust inhibitors are polar materials and<br />

retard rusting by having a stronger affinity<br />

than water for metal surfaces. Polar additives<br />

are attracted to a metal surface in a manner<br />

that iron fillings are attracted to a magnet.<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 29


CONTAMINATION CONTROL<br />

Copper Passivators<br />

Copper (metal) passivators employ chemical treatment to<br />

make the surface of metals less reactive or inactive to chemical<br />

attacks. These compounds passify, prevent or counteract<br />

catalytic effect of metals on oxidation. Typical passivators are<br />

organic nitrogen- and sulfur-containing compounds such as<br />

certain amines and sulfides.<br />

Emulsifiers<br />

Emulsifiers promote the emulsification of the free water.<br />

Specifically, these are surface-active agents that reduce interfacial<br />

tensions so oil can be finely dispersed in water.<br />

Examples include soaps of fats and fatty acids, sulfonic acids<br />

and naphthenic acids.<br />

R&O oils are necessary for use in circulating oil systems.<br />

Besides the necessity to lubricate roll necks, journals and<br />

roller bearings, effective R&O oils also act to lubricate other<br />

equipment such as drain pipes, bearing housings and reservoir<br />

ceilings. Many major steel equipment manufacturers<br />

(Morgan Construction, Danieli) and bearing manufacturers<br />

(SKF, FAG) have established specifications and guidelines for<br />

lubricant selection and performance.<br />

The standard MORGOIL specification (for a new oil) by<br />

Morgan Construction is an example of this. In recent years,<br />

many specifications have been refined to differentiate lubricants,<br />

particularly regarding their abilities to separate out<br />

water quickly and efficiently under various conditions.<br />

In the 1990s, Morgan Construction Company spearheaded<br />

an industry-wide initiative for improved lubricant<br />

performance in rolling mill bearings. The idea behind the<br />

MORGOIL advanced lubricant standard was to establish<br />

new specifications for oils that would shed water at normal<br />

operating tank temperatures (for example, 125 to 130°F)<br />

and retain the ability to shed water in service. This new specification<br />

allows for the identification of better lubricants for<br />

steel mill applications that are particularly prone to high<br />

water ingress.<br />

To differentiate the more stringent requirements of this<br />

specification from the previous standard MORGOIL requirements,<br />

lubricants meeting the criteria established by the<br />

Advanced Lubricant Specification were dubbed “super<br />

demulsibility” oils. The term super demulsibility describes<br />

lubricants that efficiently separate from water at normal<br />

operating temperatures upon return from the bearings (typically<br />

125 to 130°F). In other words, these kinds of lubricants<br />

have outstanding demulsibility characteristics.<br />

Shell Morlina Oils are an example of an oil meeting the standard<br />

MORGOIL specification. Shell Morlina SD (or super<br />

demulsibility) oils meet the criteria established by the MORGOIL<br />

Advanced Lubricant New Oil Specification. Shell Morlina T oils<br />

are used in higher-speed mill roller bearings, especially in mills<br />

that produce long bars and rods that should not undergo any<br />

twisting in the finishing process. These are all heavy-viscosity<br />

products, measuring 100 centistokes or greater.<br />

Minimize the Effects of Water<br />

Although the presence of water in steel mill operations is<br />

both essential and unavoidable, there are many things the<br />

operator can do to minimize its effect on the performance of<br />

the lubricants. Perhaps the simplest means is allowing the<br />

free water to settle out of the containment tank that holds<br />

the circulating oil. The free water may then be drained out of<br />

the bottom of the tank.<br />

Heating the tank will certainly accelerate the settling out of<br />

water, but the operator must be careful not to overheat the<br />

oil, which could induce premature oxidation. If the plant<br />

logistics allow it, a two-tank system may be used to get the<br />

most life out of the lubricants. When one oil tank becomes<br />

too saturated with water, the operator switches over to the<br />

other oil tank and drains the water from the initial tank. The<br />

process is repeated as needed.<br />

Plant maintenance personnel may benefit from the use of<br />

drop legs along the oil return lines to the tanks. As the tanks<br />

supply circulating oil to the bearings in the mill and receive<br />

the used lubricant back through return lines, many return<br />

lines contain sections of pipe protruding from them called<br />

drop legs. These drop legs accumulate water and oil as the<br />

water ingresses (enters) at each roll bearing and can be<br />

viewed to assess the condition of the lubricant.<br />

As a rule of thumb, the maintenance department will not<br />

typically allow more than two percent water in the lubrication<br />

system at any time. It is common to use a simple<br />

instrument such as the HydroScout test kit to quickly determine<br />

water content at a sampling point (drop leg).<br />

The HydroScout is a portable field test that quantifies<br />

water concentration in oil in a variety of ranges and produces<br />

instantaneous results of water content in the oil. Data generated<br />

from the HydroScout, tank temperatures, tank levels,<br />

system pressures and other parameters may be recorded<br />

several times each week to ensure that the systems are<br />

running efficiently and that the oil is performing as expected.<br />

Methods such as these allow for instantaneous estimation of<br />

the state of the lubricant and allow the operator to make<br />

recommendations on switching tanks or increasing tank<br />

temperatures immediately.<br />

Processes such as centrifugation and the application of a<br />

vacuum dehydrator are also useful to remove water from oil.<br />

30 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


Though centrifuging the oil allows for more rapid separation<br />

of water than settling alone, it will not remove dissolved<br />

water in oil. Vacuum dehydrators take this a bit further by<br />

combining a moderate heating of the oil and a large mass<br />

transfer area lower in atmospheric pressure, which acts to<br />

essentially boil off the dissolved water. Vacuum dehydration<br />

also does not remove nonvolatile additives from the oil.<br />

The mill maintenance personnel and roll shop operators<br />

can also work together to regularly inspect the<br />

chocks and seals. Chocks are the mechanical<br />

housing that holds the bearings in place and<br />

allows for sealing at the end of each roll (where<br />

lubricant comes in and most water washes<br />

out). Regular inspections identify problematic<br />

roll chocks and determine if the corresponding<br />

seals need to be replaced. The chocks themselves<br />

may be identified as needing remilling<br />

(refinishing).<br />

The roll shop can use information from<br />

regular inspections to highlight those chocks<br />

that may need to be rebuilt to specification<br />

tolerances, as well as for signs of damage, such<br />

as surface cracks in the bearing and seal<br />

leakage. Prompt corrective action can then be<br />

taken to ensure continued operation, the minimization<br />

of leaks and the prevention of<br />

mechanical failures.<br />

Finally, the selection and use of quality R&O<br />

lubricants is important to ensure smooth operation<br />

and protection of critical metal moving<br />

parts in a steel mill. Choosing well-formulated<br />

lubricants supplied by reputable oil companies<br />

should allow for excellent operation of bearings<br />

and other important moving parts.<br />

4. M. Duncanson. “Detecting and Controlling Water in Oil.” Practicing Oil<br />

Analysis magazine, September 2005.<br />

5. Edelweiss Enterprises Inc. “Emulsions.” article from www.echemical.net.<br />

6. G. Basilone, T. Wojtkowski, and L. Silva. “Dynamic Testing of Super<br />

Demulsibility Lubricants.” Iron and Steel Exposition and AISE Annual<br />

Convention, Cleveland, Ohio, September 1999.<br />

7. The <strong>Lubrication</strong> Engineers Manual. Association for Iron and Steel<br />

Engineers.<br />

About the Author<br />

Gregory Sedelmeier is the project leader of circulating<br />

and bearing oils for Shell Global Solutions Inc. He has<br />

more than 18 years experience in industrial oil and grease<br />

development. For more information, visit www.shell.com.<br />

References<br />

1. J. Wu, Y. Xu, T. Dabros, and H. Hamza. “Effect of<br />

Demulsifier Properties on Destabilization of Water-in-<br />

Oil Emulsion.” Energy Fuels, 17 (6), 2003, p.<br />

1554-1559.<br />

2. Alan Eachus. “The Trouble with Water.” Tribology and<br />

<strong>Lubrication</strong> Technology, Vol. 61, October 2005, p. 32-38.<br />

3. L. G. Ludwig. “Properties of Enclosed Gear Drive<br />

Lubricants.” <strong>Machinery</strong> <strong>Lubrication</strong> magazine,<br />

May-June 2004.<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 31


CONFERENCE REVIEW<br />

<strong>Lubrication</strong> Excellence<br />

Conference Sets Records<br />

BY JENNY KUCERA, NORIA CORPORATION<br />

The Lean, Reliable and Lubed <strong>2008</strong> conferences and exhibition,<br />

held May 20 through 22 in Nashville, Tenn.<br />

marked another record-setting event for Noria Corporation<br />

and the manufacturing sectors it serves. The international<br />

conference is the premier international event for plant<br />

management, maintenance and reliability professionals.<br />

The conferences included three co-located trade shows:<br />

Lean Manufacturing <strong>2008</strong>, Reliability World <strong>2008</strong> and<br />

<strong>Lubrication</strong> Excellence <strong>2008</strong>. It was the ninth consecutive<br />

year of attendance and exhibit growth, reflecting the high<br />

quality of the content and the broad coverage of products<br />

and services delivered to attendees.<br />

A Plentitude of Sessions<br />

Technical experts presented more than 120 sessions at the<br />

combined conferences. Each session offered a case study or<br />

technical paper – solutions to take home and apply in your<br />

plant or work environment. The <strong>Lubrication</strong> Excellence<br />

conference, in its ninth year, covered the topics of lubricants<br />

and lubrication, oil analysis, contamination control, and<br />

sludge and varnish.<br />

Reliability World, in its fourth year, addressed reliability<br />

basics, reliability management and reliability engineering.<br />

Lean Manufacturing, in its third year, presented tracks on the<br />

topics of pure lean and lean reliability.<br />

Keynote Speakers<br />

The Lean, Reliable and Lubed <strong>2008</strong> convention kicked off<br />

with a general session led by Mark Emkes, the chairman and<br />

CEO of Bridgestone Firestone North American Tire. He highlighted<br />

Bridgestone’s pursuit of innovation, reliability and<br />

lean manufacturing, and provided an in-depth look at the<br />

plant-floor initiatives that position this well-known manufacturer<br />

for continued success.<br />

Noria’s own CEO, Drew Troyer, presented a keynote<br />

session, titled “Diversify – Get the Entire Team on Board.” In<br />

it, Drew discussed the roles various organization functional<br />

groups play in the solution equation for maximizing overall<br />

business effectiveness and return on net assets. He focused<br />

on strategies for engaging the entire team of functional<br />

players in the pursuit of a lean, reliable and lubed plant.<br />

Other keynote speakers included Mark Calkins, site maintenance<br />

manager of The Boeing Company; Ross Robson,<br />

executive director of Shingo Prize; and Richard Schonberger,<br />

president of Schonberger and Associates. Among the many<br />

other valued presenters, published authors Terry Wireman,<br />

Ricky Smith and R.D. (Doc) Palmer contributed their indepth<br />

knowledge of improving maintenance strategies.<br />

A Comprehensive Exhibition<br />

The Lean, Reliable and Lubed exhibition featured products<br />

and services from more than 150 companies. Suppliers were<br />

on hand to answer questions and demonstrate solutions to<br />

32 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


problems. Activities in the exhibit hall<br />

provided opportunities for attendees to see<br />

new products in action, network with peers,<br />

and have some fun while visiting the show.<br />

Workshops<br />

Pre-conference workshops were offered in<br />

half-day and full-day sessions. Workshops<br />

centered on topics such as lean plant reliability<br />

management, maintenance planning<br />

and scheduling, zero equipment stoppages,<br />

cultural change leadership, oil analysis<br />

alarms and limits, designing a lube room,<br />

and greasing electric motor bearings.<br />

As a bonus, several industry-leading maintenance<br />

and reliability organizations offered<br />

certification exams during the conferences.<br />

Exams were offered by the International<br />

Council for <strong>Machinery</strong> <strong>Lubrication</strong> (ICML),<br />

the Society for Maintenance and Reliability<br />

Professionals (SMRP) and the Vibration<br />

Institute.<br />

In Appreciation<br />

Lean, Reliable and Lubed was presented<br />

by Noria Corporation and its <strong>Machinery</strong><br />

<strong>Lubrication</strong>, Practicing Oil Analysis and<br />

Reliable Plant magazines.<br />

The primary conference sponsors were<br />

Chevron, COT-Puritech, Des-Case, Shell,<br />

Snap-on Industrial, Whitmore Group/Air<br />

Sentry, SKF, Emerson Process Management,<br />

<strong>Lubrication</strong> Engineers, MP Filtri and Trico.<br />

Media sponsors included Pumps &<br />

Systems, Plant Services, Industrial<br />

Equipment News, Plant Engineering, Fluid<br />

Power and Industrial Maintenance and Plant<br />

Operation magazines.<br />

Endorsing organizations included ICML,<br />

ILMA, NLGI and the Vibration Institute.<br />

The 2009 Lean, Reliable and Lubed<br />

conferences and exhibition will take place<br />

April 28 through 30 in Columbus, Ohio.<br />

We look forward to seeing you there.<br />

To learn more about this and other events,<br />

visit www.machinerylubrication.com or<br />

www.noria.com.<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 33


LUBRICATION 101<br />

Basic Wear Modes in<br />

Lubricated Systems<br />

BY ROBERT SCOTT, NORIA CORPORATION<br />

This article provides a basic definition and understanding<br />

of the major wear modes or mechanisms based around<br />

the ISO 15243.2004 rolling bearing failure mode classification.<br />

Several other modes of wear that occur in gears, journal<br />

bearings, hydraulic pumps and pistons – but don’t occur in<br />

rolling bearings – will be discussed.<br />

The ISO system discusses wear in six major categories with<br />

15 subcategories.<br />

Surface Fatigue<br />

Denting by<br />

soft particles<br />

Denting by<br />

hard particles<br />

Berm<br />

Surface fatigue often begins by<br />

denting due to hard or soft particles.<br />

This creates a stress riser (berm).<br />

Repeat high loading (stress<br />

reversals) on berm or particles<br />

causes surface fatigue and<br />

eventually pits form. This leads to<br />

larger pits, then spalls.<br />

Fatigue<br />

1.1 Subsurface<br />

1.2 Surface Initiated<br />

Wear<br />

2.1 Abrasive<br />

2.2 Adhesive<br />

Corrosion<br />

3.1 Moisture<br />

3.2 Frictional<br />

3.2.1 Fretting Corrosion<br />

3.2.2 False Brinelling<br />

Dent<br />

Pit<br />

Electrical Erosion<br />

4.1 Excessive Voltage<br />

4.2 Current Leakage<br />

Plastic Deformation<br />

5.1 Overload True Brinelling<br />

5.2 Indents from Debris<br />

5.3 Indents from Handling<br />

Fracture<br />

6.1 Forced Fracture<br />

6.2 Fatigue Fracture<br />

6.3 Thermal Fracture<br />

Pitch Arc<br />

Pitch Line<br />

Fatigue Wear<br />

High Risk Contacts:<br />

rolling element<br />

bearings, gear teeth<br />

at pitchline,cams and<br />

rollers.<br />

Controlling Surface Fatigue:<br />

• Increase film thickness<br />

• Reduce surface roughness<br />

• Maximize hardness<br />

• Lower traction coefficient<br />

• High pressure-viscosity<br />

coefficient<br />

• Avoid particle contamination<br />

• Keep oil dry<br />

Pits and dents disrupt<br />

EHD film thickness<br />

Not contained in the ISO classification is Erosion from<br />

particles and Cavitation.<br />

Wear mechanisms can also be thought of as occurring in<br />

two separate categories: contact and noncontact modes.<br />

Contact wear requires the components to have direct metalto-metal<br />

contact for wear to occur. Noncontact modes do<br />

not require the surfaces to come into direct contact for them<br />

to wear; in other words, a full fluid lubricant film may exist.<br />

Subsurface Fatigue<br />

Subsurface fatigue is a form of wear that occurs after many<br />

cycles of high-stress flexing of the metal. This causes cracks in the<br />

subsurface of the metal, which then propagate to the surface,<br />

resulting in a piece of surface metal being removed.<br />

It begins with inclusions or faults in the bearing metal<br />

below the surface. Subsurface microcracks form due to longterm<br />

repeated load cycles and stress (500,000 psi), causing<br />

elastic deformation (flexing) of the metal. This is typical in all<br />

rolling bearing elements and races and gear teeth, all of<br />

which operate in the elastohydrodynamic (EHD) lubrication<br />

regime. The contact stress is concentrated at a point below<br />

the metal surface.<br />

These microcracks normally propagate to the surface, which<br />

eventually results in a piece of the surface material being<br />

removed or delaminated. They appear as surface damage or<br />

wear (large pits) referred to as spalling. Other terms for subsurface<br />

fatigue include flaking, peeling and mechanical pitting. A<br />

full oil film exists and no metal-to-metal contact or surface<br />

damage is needed. Subsurface fatigue is not a common issue if<br />

better quality metals are used in bearing manufacture. Most<br />

bearings will fail by another mechanism first.<br />

Subsurface fatigue failure is the result of a bearing living<br />

out its normal life span based on the load, speed and lubricant<br />

film thickness that it is exposed to. The L10 fatigue life<br />

34 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


LUBRICATION 101<br />

Abrasive Wear<br />

Other Names: plowing, cutting, gouging and broaching<br />

Two-Body<br />

Abrasion<br />

Three-Body<br />

Abrasion<br />

Hard Abrasive<br />

Abrasive wear occurs in sliding<br />

contacts, usually due to particle<br />

contamination.<br />

Machines/components affected by<br />

abrasive wear: piston/cylinders, swash<br />

plates, journal bearings, gears, cams,<br />

rolling element bearings<br />

Adhesive Wear<br />

“Soft” Surface<br />

“Hard” Surface<br />

“Hard” Surface<br />

“Soft” Surface<br />

Scuffing occurs on both sides of the pitch<br />

line. Changes tooth profile. Drives load<br />

density towards pitchline. Loss of involute<br />

profile increases gear noise.<br />

Adhesive wear occurs in highly-loaded, poorly<br />

lubricated slidingmachine contacts.<br />

Machine/components affectedby adhesive wear:<br />

• Pistons/cylinders • Swash plates<br />

• Gear contacts • Hypoid gears<br />

• Cams and followers • Rolling element bearings<br />

Corrosive Wear<br />

Fluid<br />

Uniform Attack<br />

Fluid<br />

Pitting Attack<br />

Imbedded<br />

Particle<br />

Scratch<br />

Marks<br />

Surface damage: scratch marking, scoring, furrows,<br />

grooves and polishing<br />

Influencing factors:<br />

• Surface hardness<br />

• Particle size/hardness<br />

• Alignment<br />

Juncture(cold weld)<br />

Fragment<br />

(material transfer)<br />

Fluid<br />

Intergranular Attack<br />

Fluid<br />

Subsurface Attack<br />

Corrosion wear is surface damage resulting from<br />

exposure to a reactive environment (atmosphere,<br />

moisture accumulation, bacteria, acids, electrolytes,<br />

process chemicals or lubricant by-products).<br />

• Film thickness (load,<br />

viscosity, speed)<br />

• Particle concentration<br />

Pitch Line<br />

Pitch Arc<br />

Scuffing and Adhesive Wear<br />

Machine surface damaged<br />

by adhesive wear<br />

Influencing Factors:<br />

• Similarity of mating surfaces<br />

• Antiscuff, EP, AW additives<br />

• Film thickness (load, viscosity,<br />

speed)<br />

• Gear tooth size<br />

• Surface roughness<br />

Corrosion rate (rust)<br />

typically doubles for every<br />

10°C (18°F) increase in<br />

temperature.<br />

Techniques to Reduce Corrosion:<br />

• Corrosion-resistant Metallurgy<br />

• Fluid Contamination Control (heat,<br />

moisture, water, acids, bacteria)<br />

• Protective Barrier (coatings, surface<br />

treatments, etc.)<br />

• Corrosion-controlling Additives (rust<br />

inhibitors, metal deactivators, overbase<br />

additive, etc.)<br />

of a bearing is the average time (in hours or cycles) to fail 10<br />

percent of a set of identical bearings under certain conditions.<br />

An estimate of the L10 life can be calculated, providing<br />

a rating life of a bearing.<br />

Surface-initiated Fatigue<br />

This begins with reduced lubrication regime and a loss of the<br />

normal lubricant film. The oil film is reduced to boundary or a<br />

mixed regime. Some metal-to-metal contact and sliding motion<br />

occurs. Surface damage occurs. The high points of the metal<br />

surface asperities are removed, which initially appear as a<br />

matted or frosted surface. This is not smearing, as in adhesion<br />

(discussed below). This type of surface damage is usually visible<br />

with a magnification of three to five times.<br />

The surface damage is coupled with the cyclic loading of the<br />

rollers rolling over the race. This creates asperity microcracks<br />

and microspalling. The cracks start at the surface and migrate<br />

down into the metal. An edge of metal is created at the surface<br />

which flexes at the edge of the surface crack. This creates a cold<br />

worked edge which is lighter in color. The cracks propagate and<br />

may intersect within the metal, and a piece of surface material<br />

is then removed. Flaking, mechanical pitting and micropitting<br />

are other names used to describe spalling.<br />

Surface fatigue can also occur as a result of plastic deformation<br />

(described below). Contaminant particles in the oil<br />

enter the high-load rolling contact area between rollers and<br />

the race, or between gear teeth, and cause some form of<br />

surface damage - a dent. Improper handling of bearings can<br />

cause similar surface damage.<br />

These round-bottomed dents often have a raised berm<br />

around their edges. The raised berm of metal acts as a point of<br />

increased load or stress, or creates a reduced lubrication regime<br />

(mixed or boundary), and leads to a lower surface fatigue life.<br />

Improved filtration reduces plastic deformation, and therefore<br />

indirectly reduces the occurrence of surface fatigue.<br />

Notice that the term “contact fatigue” is not used by ISO.<br />

This is a vague term sometimes used to describe both forms<br />

of fatigue. It does not specify whether metal flexing damage<br />

started in the subsurface or from some initial surface<br />

damage. It encompasses any change in the metal structure<br />

caused by repeated stresses concentrated at a microscopic<br />

scale in the contact zone between the rolling elements and<br />

raceways, and between gear teeth.<br />

Abrasive Wear<br />

Abrasive wear is estimated to be the most common form<br />

of wear in lubricated machinery. Particle contamination and<br />

36 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


oughened surfaces cause cutting and<br />

damage to a mating surface that is in relative<br />

motion to the first.<br />

Three-body abrasion occurs when a relatively<br />

hard contaminant (particle of dirt or<br />

wear debris) of roughly the same size as the<br />

dynamic clearances (oil film thickness)<br />

becomes imbedded in one metal surface and<br />

is squeezed between the two surfaces, which<br />

are in relative motion. When the particle size<br />

is greater than the fluid film thickness,<br />

scratching, ploughing or gouging can occur.<br />

This creates parallel furrows in the direction<br />

of motion, like rough sanding. Mild abrasion<br />

by fine particles may cause polishing with a<br />

satiny, matte or lapped-in appearance. This<br />

can be prevented with improved filtration,<br />

flushing and sealing out small particles.<br />

Two-body abrasion occurs when metal<br />

asperities (surface roughness, peaks) on one<br />

surface cut directly into a second metal<br />

surface. A contaminant particle is not directly<br />

involved. The contact occurs in the boundary<br />

lubrication regime due to inadequate lubrication<br />

or excessive surface roughness which<br />

could have been caused by some other form<br />

of wear. Higher oil viscosity, increased metal<br />

hardness and even demagnetizing bearings<br />

after induction heating during installation<br />

may help to reduce two-body abrasion.<br />

Adhesive Wear<br />

Adhesive wear is the transfer of material from<br />

one contacting surface to another. It occurs<br />

when high loads, temperatures or pressures<br />

cause the asperities on two contacting metal<br />

surfaces, in relative motion, to spot-weld<br />

together then immediately tear apart, shearing<br />

the metal in small, discrete areas.<br />

The surface may be left rough and jagged or<br />

relatively smooth due to smearing/deformation<br />

of the metal. Metal is transferred from one<br />

surface to the other. Adhesion occurs in equipment<br />

operating in the mixed and boundary<br />

lubrication regimes due to insufficient lube<br />

supply, inadequate viscosity, incorrect internal<br />

clearances, incorrect installation or misalignment.<br />

This can occur in rings and cylinders,<br />

bearings and gears.<br />

Normal break-in is a form of mild adhesive<br />

wear, as is frosting. Scuffing usually refers to<br />

moderate adhesive wear, while galling,<br />

smearing and seizing result from severe adhesion.<br />

Adhesion can be prevented by lower<br />

loads, avoiding shock loading and ensuring<br />

that the correct oil viscosity grade is being<br />

used. If necessary, extreme pressure (EP) and<br />

antiwear (AW) additives are used to reduce<br />

the damage.<br />

Corrosion<br />

Moisture corrosion involves material<br />

removal or loss by oxidative chemical reaction<br />

of the metal surface in the presence of moisture<br />

(water). It is the dissolution of a metal in<br />

an electrically conductive liquid by low<br />

amperage and may involve hydrogen embrittlement.<br />

It is accelerated, like all chemical<br />

reactions, by increased temperatures. No<br />

metal-to-metal contact is needed. It will<br />

occur with a full oil fluid film.<br />

Corrosion is often caused by the contamination<br />

or degradation of lubricants in service.<br />

Most lubricants contain corrosion inhibitors<br />

that protect against this type of attack. When<br />

the lubricant additives become depleted due<br />

to extended service or excessive contamination<br />

by moisture, combustion or other gases<br />

or process fluids, the corrosion inhibitors are<br />

no longer capable of protecting against the<br />

acidic (or caustic) corrosive fluid and corrosion-induced<br />

pitting can occur. The pits will<br />

appear on the metal surface that was exposed<br />

to the corrosive environment.<br />

This may be the entire metal surface or just<br />

the lower portion of the metal that may have<br />

been submerged in water not drained from the<br />

oil sump or at the roller/race contact points.<br />

Generally, an even and uniform pattern of pits<br />

will result from this form of attack. Mild forms<br />

of moisture corrosion result in surface staining<br />

or etching. More severe forms are referred to as<br />

corrosive pitting, electro-corrosion, corrosive<br />

spalling or rust.<br />

Frictional corrosion is a general form of<br />

wear caused by loaded micromovements or<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 37


LUBRICATION 101<br />

Erosion Wear<br />

vibration between contacting parts without any water<br />

contaminant being present, although humidity may be necessary.<br />

It may also be referred to as fretting wear. It includes<br />

both fretting corrosion and false brinelling, which in the past<br />

were often considered to be the same mechanism.<br />

Fretting corrosion is the mechanical fretting wear damage<br />

of surface asperities accompanied and escalated by corrosion,<br />

mostly oxidation in air with some humidity present. It<br />

occurs due to many oscillating micromovements at<br />

contacting interfaces between loaded and mating parts in<br />

which the lubricant has not been replenished (an unlubricated<br />

contact). Adhesion is occurring and it is generally<br />

considered more severe than false brinelling.<br />

It usually appears as a reddish-brown oxide color (rust<br />

without water being present) on steel and black on<br />

aluminum. Metal wear debris flakes are created or shed off.<br />

IMPACT!<br />

Erosion Wear Mechanism<br />

Erosion wear is the loss of material that results from repeated<br />

impact of small, solid particles; entrained gas or liquid<br />

medium, impinging on a surface at any significant velocity.<br />

Cavitation Wear<br />

Machine surface damaged by<br />

errosive wear<br />

Factors Influencing<br />

Erosion Wear:<br />

• Particle shape<br />

• Particle size<br />

• Particle hardness<br />

• Particle velocity<br />

• Temperature<br />

Fretting corrosion occurs on many mechanical devices<br />

such as gear teeth and splines, not just rolling element bearings,<br />

and can occur on surfaces other than the rolling<br />

contact. In bearings, it is also associated with bearing fit on<br />

the shaft and in the housing. It occurs where there is not any<br />

large relative motion between the mating parts such as<br />

between the shaft and the inner race and between the<br />

housing and the outer race. Fretting corrosion can occur on<br />

materials that do not oxidize.<br />

False brinelling occurs due to micromovements under<br />

cyclic vibrations in either static or rotating boundary lubrication<br />

contacts. Mild adhesion of the metal asperities is<br />

occurring. Shallow depressions or dents are created in which<br />

the original machining marks are worn off and no longer<br />

visible due to the wearing damage of the metal. False<br />

brinelling occurs on the rolling elements and raceway, similar<br />

to small-scale plastic deformation or brinelling (see below)<br />

and hence the name “false brinelling”.<br />

False brinelling is usually associated with static nonrotating<br />

equipment and, thus, the wear appears at the roller<br />

contacts with the exact same spacing as the rollers. The<br />

depressions in the metal can appear shiny with black wear<br />

debris around the edges. If the equipment is rotating, the<br />

wear appears as a gray, wavy washboard pattern on the<br />

raceway. Reduced bearing life or failure ultimately occurs,<br />

sometimes in a catastrophic fashion, through surface fatigue<br />

initiating in these damaged surface layers.<br />

An example of false brinelling occurs in standby electric<br />

motors and pumps (and others) which sit idle for periods<br />

of time, but are subjected to vibration from the plant floor<br />

up through the load-bearing rolling elements of the bearings.<br />

Antiwear additives may be beneficial in reducing the<br />

wear damage.<br />

HYDRAULIC PUMP<br />

3000 psi<br />

Initial<br />

Bubble<br />

suction<br />

Cavitation Wear Mechanism<br />

Vaporous Cavitation<br />

The process begins by the<br />

entrainment of water vapor in the<br />

oil. Later, a pressure increase<br />

causes the bubblesto collapse<br />

and produce a microjet that<br />

impinges upon and damages the<br />

surface. A 7-ounce glass of water<br />

turns into 55 gallons of steam.<br />

Collapsing<br />

Bubble<br />

Microjet<br />

Source<br />

Gaseous Cavitation<br />

As the noncompressible<br />

gas bubbles travel into<br />

high-pressure regions,<br />

they collapse, producing<br />

intense pressures and<br />

damaging the surface.<br />

Pump valve plate damaged<br />

by cavitation wear<br />

Machine/elements affected by<br />

cavitation wear<br />

• Control valves<br />

• Pumps<br />

• Actuators<br />

• Valve seats<br />

• Spool lands<br />

• Journal bearings<br />

Electrical Erosion<br />

This type of wear occurs when electric current passes<br />

between two metal surfaces (for example, bearing roller and<br />

race) through the oil or grease film. It is subdivided based on<br />

the severity of the damage. Electrical erosion should not be<br />

confused with erosion caused by particles (discussed below).<br />

Excessive voltage (electrical pitting) is caused by a high electrical<br />

current or amperage passing through only a few<br />

asperities on the metal. Voltage builds up and then arcs,<br />

causing localized heating/melting and vaporization of the<br />

metal surface. This causes deep, large craters or pits in the<br />

metal surfaces, which may correspond to the spacing between<br />

the rolling elements of the bearing. It is possibly due to welding<br />

38 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


in the area and inadequate grounding or insulation.<br />

It may also be referred to as electrical<br />

pitting, arcing or sparking.<br />

Current leakage (electrical fluting) is a less<br />

severe form of damage caused by a lower<br />

continuous electrical current. The damage<br />

may be shallow craters that are closely positioned<br />

and appear dark gray in color. If the<br />

electrical discharge occurs while the bearing is<br />

in motion, with a full fluid film, a washboard<br />

effect or grooves appear on the entire bearing<br />

raceway and is called fluting or corduroying.<br />

Plastic Deformation<br />

This is the denting, indentations or depressions<br />

in the race or rollers caused by impact or<br />

overloading. The surface metal flows, causing<br />

irreversible deformation (not wear). The<br />

machining marks are still visible in the bottom<br />

of the dent. The dents often have a raised lip<br />

which increases stresses and leads to surfaceinitiated<br />

fatigue (surface cracks) and eventual<br />

pit formation or adhesive wear. Plastic deformation<br />

consists of three subcategories.<br />

Overload or true brinelling is characterized<br />

by static or shock loading, or impact from<br />

operational abuse, causing a permanent dent<br />

in the metal without cutting or welding of the<br />

metal. An example occurs in roller bearings<br />

when impact causes the rollers to create a<br />

series of dents in the bearing race surface at<br />

intervals that match the roller spacing exactly.<br />

Some people consider denting from the<br />

impact of hammering on a bearing as overload;<br />

others may consider it as an indentation<br />

from handling.<br />

Indentation from debris is a form of plastic<br />

deformation but it is caused by a particle<br />

trapped within the dynamic clearances<br />

between two machine elements and being<br />

over-rolled. The force causes a round-bottom<br />

dent to form in the race or rolling element.<br />

Cracks may propagate down into the metal.<br />

Indentation from handling is similar to<br />

that from debris, but results from a bearing<br />

being dropped or hammered, causing localized<br />

overloading. It can also be due to nicks<br />

from hard or sharp objects.<br />

It is common to encounter erosion from<br />

particles in the oil and cavitation, although<br />

this is not included in the ISO standard for<br />

rolling bearings.<br />

Erosion<br />

Erosion could be considered a form of abrasive<br />

wear. It occurs principally in high-velocity,<br />

fluid streams where solid particle debris,<br />

entrained in the fluid (oil), impinges on a<br />

surface and erodes it away. Hydraulic systems<br />

are an example where this type of wear may<br />

occur. Flow rates have a significant influence<br />

on these wear rates, which are proportional to<br />

at least the square of the fluid velocity. Erosion<br />

typically occurs in pumps, valves and nozzles.<br />

Metal-to-metal contact does not occur. The<br />

mechanism of erosion is used to an advantage<br />

in water-jet cutting.<br />

Cavitation<br />

This is a special form of erosion in which<br />

vapor bubbles in the fluid form in low-pressure<br />

regions and are then collapsed<br />

(imploded) in the higher-pressure regions of<br />

the oil system. The implosion can be powerful<br />

enough to create holes or pits, even in hardened<br />

metal if the implosion occurs at the<br />

metal surface. This type of wear is most<br />

common in hydraulic pumps, especially those<br />

which have restricted suction inlets or are<br />

operating at high elevations.<br />

Restricting the oil from entering the pump<br />

suction reduces the pressure on the oil and,<br />

thus, tends to create more vapor bubbles.<br />

Cavitation can also occur in journal bearings<br />

where the fluid pressure increases in the load<br />

zone of the bearing. No metal-to-metal<br />

contact is needed to create cavitation.<br />

Just to be clear, pitting is a general term<br />

used in failure analysis to describe almost any<br />

small, rough-bottomed, circular potholes in<br />

the metal surface. Pits can be caused by<br />

mechanical pitting (fatigue or cavitation),<br />

chemical pitting (corrosion) or by electrical<br />

pitting (stray arcing), all of which are<br />

described above.<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 39


LUBRICATION 101<br />

Failure analysis is used to assign a wear mechanism to a specific<br />

failure. If the wear mechanism can be determined, then some corrective<br />

action can be applied to prevent the failure from recurring. Often, it can<br />

be useful to use the process of elimination to determine which wear<br />

mechanisms could not have produced the observed wear pattern, thus<br />

reducing the number of possible mechanisms. Unfortunately, combinations<br />

of wear mechanisms exist in most situations, thus complicating the<br />

selection of the optimum wear-resistant system.<br />

Acknowledgment<br />

Several portions of this article may contain residual wording from an<br />

article that was originally written by Rees Llewellyn of the National<br />

Research Council of Canada for the Alberta section of the Society of<br />

Tribologists and <strong>Lubrication</strong> Engineers (STLE).<br />

About the Author<br />

Bob Scott is a senior technical consultant for Noria, and has more than 25 years of<br />

technical experience with lubricants, lubrication and related machinery. He has written<br />

and presented technical papers to lubricant technical societies and lubrication conferences<br />

and has developed and presented training sessions for maintenance and lubricant<br />

sales personnel.<br />

He is certified as a <strong>Lubrication</strong> Specialist (CLS) and Oil Monitoring Analyst (OMA)<br />

Levels I and II by STLE. Bob is also ICML Level I and II MLT certified.<br />

40 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


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and can be accessed for<br />

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Fluid Metering Inc.<br />

www.fmipump.com<br />

pumps@fmipump.com<br />

800-223-3388<br />

Bearing Materials<br />

Metallized Carbon Corporation introduces Metcar grades M-161<br />

and M-162 mechanical materials for running at elevated temperatures.<br />

The carbon/graphite Babbitt are designed to operate in difficult environments,<br />

at temperatures up to 350°F. These grades are typically used<br />

for moderate loads at medium and high speeds. The bearings are selflubricating,<br />

nongalling, dimensionally<br />

stable and have high compressive<br />

strength. The Babbitt impregnation<br />

provides wear resistance<br />

and enhanced lubrication for<br />

bearing and thrust washers<br />

for submerged and dry<br />

environments.<br />

Metallized Carbon Corporation<br />

www.metcar.com<br />

sales@metcar.com<br />

914-941-3738<br />

Basket Strainers<br />

Micromold Products Inc. has developed a highly corrosionresistant,<br />

all-plastic Fluor-O-Shield basket strainer that captures<br />

substantial undissolved solids. The Kynar PVDF basket strainers<br />

remove suspended or waste solids from corrosive or high-purity fluid<br />

streams to prevent damage to sensitive downstream equipment. The<br />

strainers are impervious to UV radiation, are FDA-compliant, resistant<br />

to radiation and hot acids, and are capable of handling nuclear waste<br />

processing. Sizes range from one-half to three inches, with a variety of<br />

connections and mesh screens available.<br />

Micromold Products Inc.<br />

www.micromold.com<br />

webinfo@micromold.com<br />

914-969-2850<br />

Oil Absorbents<br />

PetroLiance LLC has expanded its Medallion Plus product line to<br />

include a new selection of industrial absorbent for use in a variety of<br />

industrial, automotive and<br />

maintenance applications. The<br />

Medallion Plus DE oil absorbent<br />

was developed to provide better<br />

performance and ease of<br />

handling than other adsorbent<br />

and floor-dry materials, including<br />

bentonite clay or cellulose-based<br />

absorbents. The product can be<br />

disposed of similar to conventional<br />

refuse.<br />

PetroLiance LLC<br />

www.petroliance.com<br />

800-628-7231<br />

Filter Cart<br />

Donaldson’s new filter cart includes two in-series pressure filters<br />

that remove course/fine particulate matter.<br />

A water-absorbing element may also be<br />

installed to further remove particulate<br />

matter and water. Its powerful onehorsepower<br />

motor coupled with a<br />

10-gallon per minute pump provides<br />

efficient fluid transfer and filtration for<br />

industrial hydraulic applications. Features<br />

include a safety relieve valve, an overload<br />

protected switch, a rear-mounted motor, a<br />

removable angled drip tray and clear<br />

braided hoses.<br />

Donaldson Company<br />

www.donaldson.com<br />

952-887-3131<br />

42 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


LUBRICANT APPLICATION<br />

Improving Oven<br />

Chain <strong>Lubrication</strong><br />

A Discussion of High-temperature Environments<br />

BY JEFFREY E. TURNER, LUBRICATION ENGINEERS INC.<br />

Maximum<br />

Service<br />

Temperature<br />

Chains operating at high temperatures can be lubricated<br />

in two different ways: with a liquid lubricant, or with a<br />

solid lubricant suspended in a carrier fluid. Whether solid or<br />

liquid, the lubricating film physically separates contacting<br />

metal surfaces, thereby reducing friction and wear.<br />

Fluid Film <strong>Lubrication</strong><br />

Fluid film lubrication is the regular oil film lubrication<br />

used in most ambient temperature applications. This type of<br />

lubrication can also be used at higher temperatures, provided<br />

that you take into account the decreased viscosity of the fluid<br />

(thinner oil film), the increased oxidation rate of the oil (can<br />

leave varnish and sludge), and the volatility of the oil (as it<br />

evaporates, there is less oil with which to lubricate).<br />

Al Mg Si Molybdenum Disulfide Graphite Fluorocarbon<br />

(Almasol)<br />

(PTFE)<br />

1038°C<br />

1900°F<br />

343°C<br />

650°F<br />

426°C<br />

800°F<br />

260°C<br />

500°F<br />

Load-carrying 400,000 400,000 80,000 5,000<br />

Capacity, psi 2<br />

<strong>Lubrication</strong><br />

Mechanism<br />

Acid<br />

Resistance<br />

Comments<br />

Slippage<br />

between<br />

particles<br />

Inert<br />

Has a natural<br />

affinity to metal<br />

as a result of<br />

surface attraction.<br />

Will not<br />

build up on<br />

itself or affect<br />

machine tolerances.<br />

Shearing of molecular bonds<br />

Some – cannot tolerate<br />

hydrochloric acid, nitric acid,<br />

fluorine, chlorine, pure oxygen<br />

Oxidizes in air above 343°C<br />

(650°F) to form molybdenum<br />

trioxide, which is abrasive.<br />

Tendency to build up on itself<br />

and affect close tolerances.<br />

Cannot tolerate hydrochloric<br />

acid and nitric acid, which are<br />

often present in lubricant environments,<br />

especially where heat,<br />

water and air are present.<br />

Table 1. Various Technologies 2,3,4,5<br />

Slippage<br />

between<br />

particles<br />

Some<br />

Galvanic<br />

corrosion<br />

problems.<br />

Tendency<br />

to build<br />

up<br />

on itself.<br />

Polymer<br />

alters<br />

orientation<br />

Inert<br />

No loadcarrying<br />

capacity.<br />

Tendency to<br />

build up on<br />

itself.<br />

A variety of synthetic base oils (polyalphaolefins [PAO],<br />

esters, silicones) enable lubrication at higher temperatures<br />

than petroleum oils. They have the same limitations (thinning<br />

out, oxidizing and evaporating) as petroleum oils, just at<br />

higher temperatures.<br />

At higher operating temperatures, frequent lubrication is<br />

required to replace the fluid lost to evaporation. The evaporation,<br />

oxidation and decrease in viscosity make proper<br />

lubrication difficult to achieve with a liquid lubricant alone.<br />

In such cases, using a solid lubricant provides better wear<br />

protection and consumes less lubricant.<br />

Solid Film <strong>Lubrication</strong><br />

Solid film lubrication is used at high temperatures or in<br />

applications where it is impossible or undesirable to use a<br />

liquid. The solid is usually suspended in a liquid carrier<br />

designed to disperse (evaporate) after the lubricant has been<br />

applied and, in the case of chains, after it has penetrated in<br />

to the pin area of the chain. The example that most people<br />

are familiar with is graphite powder dissolved in kerosene,<br />

but technology has advanced well beyond this.<br />

Solid lubricants provide a smooth, low-drag surface,<br />

which reduces friction, wear, operating temperatures and<br />

electrical energy consumption.<br />

The choice of the specific type of solid lubricant technology<br />

has an enormous impact on performance and should<br />

not be taken lightly. Materials commonly used as solid lubricants<br />

include molybdenum disulfide (MoS 2), graphite (C),<br />

fluorocarbon polymers such as polytetrafluoroethylene<br />

(PTFE, commercially known as Teflon), metallic oxides, and a<br />

highly refined powder of aluminum, magnesium and silicate<br />

(commercially known as Almasol). Table 1 shows a comparison<br />

of these technologies.<br />

44 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


LUBRICANT APPLICATION<br />

On a microscopic level, all metal surfaces are uneven and<br />

have high and low spots. The high points, called asperities,<br />

on opposing working surfaces meet under heavily loaded<br />

conditions and the instantaneous contact temperatures of<br />

these asperities often exceed 1,000°F. Pressures in the<br />

contact zone can also exceed 175,000 psi. 1 Only the Al-Mg-<br />

Si technology meets these needs and remains inert and intact<br />

under these extremes of temperature and load.<br />

Neither graphite nor PTFE has sufficient load-carrying<br />

capacities, and “moly” becomes abrasive, which causes wear.<br />

Consequently, NASA has used the Al-Mg-Si solid film technology<br />

on every manned U.S. space flight including the lunar<br />

landings and the space shuttle. 6,7<br />

The size and the morphology of the particles of the Al-Mg-<br />

Si powder are carefully controlled. These particles are<br />

platelets, which form a single-layer coating on the surface of<br />

the metal through particulate attraction. These particles<br />

carry the load when the hydrodynamic oil film is gone<br />

(squeezed out or evaporated off), preventing metal-to-metal<br />

contact.<br />

Reduction in Friction<br />

The reduction in friction translates into less wear, cooler<br />

operating temperatures and smaller electricity bills. The<br />

energy savings alone typically pay for the lubricant several<br />

times over. The most noticeable differences are the elimination<br />

of squealing and screaming of the chains. Another<br />

benefit is that the Al-Mg-Si powder does not build up on<br />

itself or make a mess like graphite does.<br />

Carriers<br />

Different carriers allow the solid lubricant to be applied at<br />

different temperatures. For room-temperature application,<br />

Figure 1. Tortilla Chips Entering Casa Herrera Tunnel Oven<br />

light carriers such as kerosene are used. But if the chains are<br />

hot, the low flash point of these fluids is a fire hazard, so a<br />

variety of synthetic carriers are employed.<br />

The best ones are smokeless and odorless. Unlike lubricants<br />

that rely on the fluid to provide the lubrication film, the<br />

evaporation rate of these products should be high rather<br />

than low because the oil is only a carrier to take the solids to<br />

where they are needed - inside the pin and bushing area.<br />

In severe applications, the chain can be lubricated both<br />

when it is hot and when it is cool by using the same solid<br />

lubricant but with two different carrier fluids. This is exactly<br />

what is done at a major light bulb plant in Canada. A low<br />

flash point chain lubricant containing Al-Mg-Si is applied<br />

during downtime between production runs, when the chain<br />

is cool.<br />

The light carrier ensures proper penetration into the links<br />

of the chain at these cool temperatures. During extended<br />

production runs, a smokeless, odorless, high flash point<br />

chain lubricant is applied to the hot chain as required.<br />

Because the chain is hot, this heavier carrier rapidly thins out<br />

and penetrates into the pin area of the chain.<br />

When using lubricants containing suspended solids, it is<br />

important to agitate them before application. Many plants<br />

apply them to oven chains by hand using a garden hand<br />

sprayer (the type you pump, shake and spray) and apply<br />

them only once every week or two. There are also automatic<br />

lubrication systems, which circulate or agitate the fluid (to<br />

keep the solids in suspension) and then spray the fluid to the<br />

appropriate points on the chain.<br />

When switching over from a liquid film lubricant or when<br />

lubricating a new chain, the chain needs to be impregnated<br />

with the solid lubricant, initially requiring frequent application.<br />

Once the solids are in the chain, additional lubricant is<br />

required only to replenish the lost solids, and the amount of<br />

lubricant can be reduced significantly.<br />

Frequency<br />

The frequency and amount of lubricant required depends<br />

on the temperature and other aspects of the operation, but<br />

in general, you should start lubricating every other day and<br />

extend lubrication intervals from there. Because most<br />

bakeries apply lubricant on the weekends when the chains<br />

are cold, they typically apply a solid lubricant in a light<br />

carrier once a week, then extend this to once every two or<br />

three weeks. If you use a drip system, you will have to apply<br />

the lubricant more frequently because it applies less<br />

lubricant at a time.<br />

46 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


Another way of optimizing the lubrication frequency and amount is<br />

to measure the amperage required to drive the chain. As the lubricant<br />

gets depleted, the friction increases, using more electricity. This<br />

provides a useful feedback loop indicating that more lubricant is<br />

required. This is also a great way to evaluate chain lubricants, because<br />

the better they work, the lower the amperage draw will be.<br />

Case Studies<br />

Bakery<br />

A large bakery in Argentina, Bimbo de Argentina, operates Stewart<br />

ovens with skate wheel chains operating at more than 200°C (392°F).<br />

The chains are lubricated with a centralized system. By changing the<br />

type of chain lubricant, personnel eliminated buildup on the chains,<br />

recorded significant amperage drops and reduced the amount of lubricant<br />

applied. The starting amperage dropped from four amperes<br />

(amps) to two amps, and the operating amperage dropped from<br />

between 0.70 and 0.90 amp to between 0.50 and 0.80 amp.<br />

Powder Coater<br />

Rainbow Powder Coaters Ltd. in Auckland, New Zealand has an<br />

overhead bi-planar chain passing through on-line pretreatment,<br />

powder booth and gas oven. The paint is cured at 190 to 210°C (375 to<br />

410°F), so the overhead chain is exposed to a variety of conditions. Its<br />

carbon buildup and wear caused jerky, noisy operation of the line.<br />

To fix it would require pulling out the chain, costing at least three<br />

days downtime plus solvent, and building a soak-trough. Faced with<br />

this costly alternative, personnel were open to trying a more technologically<br />

advanced chain lubricant to clean and lubricate the chain without<br />

stopping production. The chain ran smoothly and remained clean.<br />

“I remember you came in when I was very busy with the most<br />

expensive oil I’ve ever seen and told me it would clean my chain. I<br />

didn’t believe it could be done. You did a good job. The chain hasn’t<br />

stopped, there is no mess and it has saved us thousands of dollars,”<br />

said owner Brian Barton.<br />

Bakery<br />

Bluebird Baking company is located in Detroit, Mich. It produces a<br />

variety of baked goods, including hotdog and hamburger buns, using<br />

Wilco tunnel ovens. The company was experiencing heavy carbon<br />

deposits on its chains and even on some of its baked goods. In 1989,<br />

the bakery decided to try an oven chain lubricant containing the Al-Mg-<br />

Si technology.<br />

The change in lubricant resulted in a 26 percent reduction in power<br />

consumption, from 4.60 amps to 3.40 amps. This 1.2-amp reduction<br />

amounts to more than $288 per year in energy saving on just one<br />

Wilco oven. The new lubricant also cleaned up the deposits from<br />

the chains.<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 47


LUBRICANT APPLICATION<br />

Bakery<br />

At Mary Ann’s Baking Company in Sacramento, Calif.,<br />

similar results were observed on its Chubco Super-Flo oven.<br />

Amp meter readings on the oven dropped almost 40 percent<br />

after converting to the Al-Mg-Si oven chain lubricant.<br />

Light Bulbs<br />

At the Philips light bulb plant in Weert, The Netherlands,<br />

the life of oven chains was substantially increased by<br />

switching to the Al-Mg-Si technology, saving at least six hours<br />

of downtime at 4,200 lamps per hour.<br />

Pretzels<br />

The Rold Gold Foods division of Frito-Lay Inc. in Canton,<br />

Ohio produces a variety of pretzels. One of its ovens has a<br />

chain drive kiln screen used in the baking process. The<br />

commercial-grade lubricant in use had a graphite base, was<br />

black and messy.<br />

If this lubricant was not applied on a regular weekly basis,<br />

the chains would bind up, which in turn tripped the main<br />

power for the oven and shut down production. This problem<br />

occurred six to eight times a year. Temperatures of the oven<br />

where the chains pass through are 475°F, with pretzel dust<br />

and salt present.<br />

Since switching from graphite to Al-Mg-Si, Rold Gold has<br />

never had a power failure due to buildup of graphite or lack<br />

of lubrication. The company uses less lubricant than with the<br />

old chain lubricant used in the past, and they appreciate the<br />

improved cleanliness of the chains.<br />

Conclusion<br />

Significant operational efficiencies can be achieved by<br />

selecting chain lubricants and application methods that<br />

match the specific operating environment and failure mode<br />

of the chain.<br />

As illustrated by several case studies, an applicationspecific<br />

chain lubricant designed to combat the enemy<br />

(water, dust, heat, etc.) saves a considerable amount of<br />

money in downtime, cleaning, lubrication, repairs, replacement<br />

chain and even electricity. Consider the factors that<br />

shorten your chain life and what are you’re going to do to<br />

prevent them.<br />

About the Author<br />

Jeffrey E. Turner is executive vice president for <strong>Lubrication</strong> Engineers,<br />

Inc. Company information can be found at www.le-inc.com.<br />

Related Reading<br />

Christopher Barnes. “Improving Chain <strong>Lubrication</strong>.” <strong>Machinery</strong><br />

<strong>Lubrication</strong> magazine, March 2005. Past issues of ML can be read online<br />

at www.machinerylubrication.com.<br />

References<br />

1. Robert Errichello. “The <strong>Lubrication</strong> of Gears.” Gear Technology<br />

Magazine, 1991.<br />

2. Anthony Gaskell. “Molybdenum Disulfide: New Life for Old<br />

Technology.” Lubricants World Magazine, <strong>August</strong> 1998.<br />

3. United States Steel. <strong>Lubrication</strong> Engineers Manual, Appendix II.<br />

4. S.F. Calhoun. “Wear and Corrosion Tendencies of Molybdenum<br />

Disulfide Containing Greases.” U.S. Army, <strong>August</strong> 1962.<br />

5. CRC Handbook of <strong>Lubrication</strong>, Vol.II. 1984, p. 269–276.<br />

6. R.J. Neely and Everette O. Walden. “ALMASOL – Key to New Vistas of<br />

<strong>Lubrication</strong> Power.” Engineering Magazine.<br />

7. Everette O. Walden. Various records, The ALMASOL Corporation.<br />

Would You Like to Contribute?<br />

Are you a technical expert? We want to publish your lubrication<br />

article in <strong>Machinery</strong> <strong>Lubrication</strong>. To submit a technical article,<br />

review the guidelines at www.machinerylubrication.com and send<br />

article to jkucera@noria.com.<br />

48 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


LIT RACK<br />

VARNISH MITIGATION plus particle and water<br />

removal! 3 problems – 1 solution. C.C. Jensen offers<br />

the only technology in the world that will remove<br />

soluble and insoluble contaminants simply and<br />

economically. Filter systems available in three styles:<br />

off-line, skid-mounted and filter carts. Call or visit<br />

the Varnish Removal Experts today!<br />

C.C. Jensen, Inc.<br />

www.ccjensen.com 800-221-1430<br />

High Velocity Oil Flushing is critical to equipment<br />

reliability. As the leading flush contractor in<br />

the country, COT-PURITECH provides turnkey<br />

programs to manage your entire oil flush project.<br />

From High Velocity Flushing to Varnish Removal<br />

Services, COT-PURITECH sales engineers will<br />

work with you to develop a reliability program<br />

specifically for you.<br />

COT-PURITECH<br />

sales@cot-puritech.com/www.cot-puritech.com<br />

888-478-6996<br />

Lean Plant Reliability Advantage is an executive<br />

summit that will challenge how you currently operate<br />

your plants. You will gain a better understanding<br />

about design, operations and maintenance to help<br />

you develop and implement a cohesive reliability<br />

strategy that supports your company’s mission and<br />

goals, which can positively influence share price and<br />

competitive position.<br />

Noria Corporation<br />

www.noria.com 800-597-5460<br />

Donaldson announces an expanded line of<br />

T.R.A.P. breather filters. T.R.A.P. breathers are now<br />

available in a variety of configurations including ABS<br />

plastic and epoxy-coated steel constructions; NPT, BSP<br />

and bayonet connections; and with or without electronic<br />

indicator options to fit a broad range of<br />

applications. T.R.A.P. Breather … Moisture meets its<br />

match. Call 800-846-1846 for a free brochure.<br />

More information available at<br />

www.donaldson.com/en/ih/accessories/trap.html<br />

<strong>Lubrication</strong> management and bearing reliability<br />

with ultrasound. UE Systems’ new Ultraprobe<br />

10,000 provides total data management, trending<br />

and spectral analysis. Alarm reports can create<br />

lubrication schedules or report failed bearings. For<br />

information: e-mail: info@uesystems.com<br />

www.uesystems.com 800-223-1325<br />

Filmax AFS has introduced a new revolutionary<br />

(patent applied for) varnish control technology<br />

implementing an electronically activated filtration<br />

method. This new technology is changing the landscape<br />

for varnish and hard contamination removal<br />

by creating unparallel cleanliness in lubricating oils<br />

and lubricating systems. The Filmax AEFS solution<br />

quickly and efficiently restores fluids to pristine<br />

conditions, maximizing equipment and fluid<br />

performance and increasing equipment reliability.<br />

Filmax, Inc.<br />

www.filmaxinc.com 800-321-3895<br />

The Vaisala HUMICAP ® Hand-held Meter MM70<br />

measures moisture and temperature in oil. Ball valve<br />

provides direct insertion into a pressurized pipe or<br />

vessel – no waiting for lab results! Graphical display,<br />

data logging and transfer to PC. Compatible with most<br />

types of oil and hydraulic fluid.<br />

www.vaisala.com/MM70<br />

instruments@vaisala.com<br />

888-VAISALA (824-7252)<br />

Performance Lubricants and Compounds for<br />

Demanding Applications. For extreme service conditions<br />

or to extend maintenance intervals, Jet Lube<br />

formulates specialized anti-seizes, thread sealants, EP<br />

greases, lubricants, super penetrants, coatings,<br />

cleaners, degreasers and anaerobic compounds for<br />

numerous industries. A full range of environmentally<br />

friendly performance compounds is included in this<br />

24-page catalog.<br />

Jet-Lube, Inc.<br />

www.jetlube.com 713-674-7617<br />

This training DVD includes instructive videos<br />

and animations to give viewers a better understanding<br />

of the types of electric motor bearings<br />

and how to lubricate them properly.<br />

Noria Corporation<br />

www.noria.com/secure 800-597-5460<br />

50 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


Polyethylene bulk oil tanks. Completely assembled,<br />

low maintenance polyethylene tanks with built-in graduated<br />

gallon indicators, are the future design for bulk oil<br />

systems. Standard equipment: 3:1 pump, 30-foot hose<br />

reel, electronic meter, meter bracket, air regulator/filter.<br />

Available in 200 and 300 gallons.<br />

Petroleum Tank Co.<br />

985-320-6153<br />

jcarr44@bellsouth.net<br />

A new full-color 104-page catalog is available on<br />

Oil-Rite’s lubrication equipment featuring PurgeX ®<br />

Centralized <strong>Lubrication</strong> Systems. Complete turnkey<br />

systems are available for immediate delivery, liquid<br />

or grease delivery, air or electric motor-operated.<br />

The catalog also features an entire line of level<br />

gauges, lubricators, valves, vent plugs and filters.<br />

www.oilrite.com 920-682-6173<br />

LE’s NSF H1 food-grade lubricants offer<br />

improved productivity and lower maintenance costs<br />

through extended equipment life and greater reliability.<br />

Discover how to increase your food plant’s<br />

profits by protecting your equipment with LE<br />

Enhanced Lubricants.<br />

www.le-inc.com 800-537-7683<br />

The Contamination Control Monitor CCM 01 is<br />

an efficient and robust inline diagnostic measuring<br />

system for stationary and permanent operations for<br />

determining contamination classes according to ISO<br />

4406:99 and NAS 1638.<br />

The Metal Particle Monitor MPM 01, an inexpensive<br />

monitoring solution for stationary and<br />

permanent operation, for detecting and counting of<br />

metal particles >200μm, with an automatic monitoring<br />

function and data storage possibility.<br />

sales@atico-internormen.com www.internormen.com<br />

A2 Technologies has developed fully portable<br />

(FTIR) spectrometers for lubrication analysis. The<br />

PAL Series (Portable Analyzers for <strong>Lubrication</strong>)<br />

provides an immediate snapshot of parameters<br />

that define the health of a lubricant. Effectively<br />

measure water, oxidation and additive depletion<br />

on-site in less than a minute!<br />

www.a2technologies.com 203-312-1100<br />

vlopez@a2technologies.com<br />

Earthkeeper, Whitmore’s complete line of<br />

high-performance, biodegradable lubricants,<br />

meets or exceeds industry standards and protects<br />

your valuable equipment while protecting the environment.<br />

The Earthkeeper family includes<br />

hydraulic oil, bearing grease, gear oil and lubricants<br />

for industrial chains, wire ropes and open gears.<br />

www.whitmores.com 800-699-6318<br />

Using the Drum Recycling Wand and a filter cart,<br />

both the suction line and the return line are connected in<br />

a “kidney” loop. Machine lubricating oils can now be<br />

reconditioned in the oil room, one drum at a time. For<br />

commercial recyclers, lubricating oil received in the<br />

client’s drum can be reconditioned, samples drawn<br />

before and after for analysis, then returned to the client in<br />

the original drum without the need for further handling.<br />

JLM Systems Limited<br />

www.oilmiser.com 888-736-8645<br />

Herguth Laboratories is an ISO 9001:2000<br />

quality supplier of analytical services with<br />

proven competencies in analyzing oil, fuel,<br />

grease, tribological and special investigations.<br />

Quality programs include: 10CFR50 Part 21<br />

Appendix B, Radioactive Licensed, ISO<br />

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www.herguth.com<br />

800-OIL-LABS (645-5227)<br />

Easy Vac, Inc. provides the right tool for an<br />

important job! Vampire fluid sampling pumps ...<br />

small, hand-operated vacuum pumps accept any<br />

size sampling tube (with an OD of 3/16 inch to<br />

5/16 inch) without changing filters. “Super Clean”<br />

sampling containers, tubing and accessories are<br />

also available.<br />

www.easyvac.com 865-691-7510<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 51


BOOKSTORE<br />

Welcome to <strong>Machinery</strong> <strong>Lubrication</strong>’s Bookstore, designed to spotlight<br />

lubrication-related books. For a complete listing of books of interest to<br />

lubrication professionals, check out the <strong>Machinery</strong> <strong>Lubrication</strong> Web site at<br />

www.machinerylubrication.com.<br />

<strong>Machinery</strong> Oil Analysis - Methods,<br />

Automation & Benefits<br />

Publisher: STLE<br />

Price: $165.00<br />

Synthetics, Mineral Oils, and Bio-Based<br />

Lubricants: Chemistry and Technology<br />

Publisher: CRC Press<br />

Price: $224.00<br />

In a single, unique volume, Synthetics, Mineral Oils, and Bio-<br />

Based Lubricants offers property and performance information<br />

of fluids, theoretical and practical background to<br />

their current applications, and strong indicators for<br />

global market trends that will influence the industry<br />

for years to come.<br />

Oil Analysis<br />

Basics<br />

Publisher: Noria Corporation<br />

Price: $40.00<br />

Written by the editors<br />

of Practicing Oil Analysis<br />

magazine, Jim Fitch and Drew<br />

Troyer, this book will prove to<br />

be a great resource for anyone involved in oil analysis<br />

or lubrication.<br />

Oil Analysis Basics makes oil analysis for machinery<br />

condition monitoring easy to understand. You will<br />

learn everything from how to take a proper oil sample<br />

to how to select a test slate for your applications.<br />

NEW! UPDATED<br />

FOR <strong>2008</strong>!<br />

The book uniquely presents the entire philosophy and practice of oil<br />

analysis as a condition monitoring tool for machines. This in-depth<br />

analysis describes the what, when, where and how-to for: <strong>Machinery</strong> lubrication concepts;<br />

<strong>Machinery</strong> failure and maintenance concepts; <strong>Machinery</strong>, fluid and filtration failure<br />

modes; Oil sampling and testing; and Statistical analysis and data interpretation.<br />

<strong>Lubrication</strong> Fundamentals<br />

Publisher: Marcel Dekker<br />

The Practical Handbook of<br />

<strong>Machinery</strong> <strong>Lubrication</strong><br />

Author: L. Leugner<br />

Price: $70.00<br />

If you want to establish yourself as the lubrication expert<br />

in your company, this book is a must-read. Once you pick it<br />

up, you won’t put it down until you’ve finished it. It’s that<br />

easy to read.<br />

Price: $119.95<br />

Thoroughly updated<br />

and rewritten since the<br />

previous edition reached<br />

its 10th printing, the<br />

second edition of<br />

<strong>Lubrication</strong> Fundamentals<br />

contains a new chapter<br />

dedicated to the refining<br />

process, highlighting the<br />

latest technology and<br />

detailed descriptions of base stocks; coverage of<br />

hydraulic systems, novel environmental lubricants and<br />

current lubricant testing methods; an examination of<br />

the latest lubrication requirements, petroleum crude<br />

selection and product formulation and evaluation; and<br />

more.<br />

There is a free bonus package when you order<br />

this item.<br />

How to Grease a Motor Bearing<br />

Format: DVD<br />

Publisher: Noria Corporation<br />

Price: $695.00<br />

Discover how to reduce bearing failures and<br />

increase uptime … in less than 40 minutes.<br />

Introducing the first DVD of Noria’s new Reliable<br />

Skills Training Series: How to Grease a Motor Bearing.<br />

High-quality animations visually demonstrate different types of electric motor bearings<br />

and how to lubricate them properly.<br />

For descriptions, complete table of contents and excerpts from these and<br />

other lubrication-related books, and to order online visit:<br />

www.machinerylubrication.com or call 1-800-597-5460, ext. 104<br />

52 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


NLGI UPDATE<br />

Introducing the<br />

Latest Word on Grease<br />

BY DAVID COMO, DOW CORNING CORPORATION<br />

Are you aware that some calcium-thickened greases may<br />

start to melt and break down at 95°C (200°F), while<br />

some complex or clay-thickened greases can approach<br />

260°C (500°F) intact? Did you know that polyurea-thickened<br />

greases are inherently less susceptible to oxidation than<br />

their metal ion-containing brethren thickened with soaps?<br />

How about the historical fact that traces of materials<br />

similar to those used to form today’s complex greases were<br />

found on chariot hubs from as far back as 1400 B.C.? These<br />

bits of information and more can be found in one compact<br />

and easy-to-understand handbook, the NLGI Lubricating<br />

Grease Guide (LGG), which was originally published nearly<br />

25 years ago.<br />

In the past, matters of lubrication training on the shop<br />

floor had been left to either the technician being replaced or<br />

the guy working at the next bench. It happened similarly in<br />

the original equipment (OE) design area. This results in<br />

untrained people passing on their practices to other<br />

untrained people, which invariably leads to misinterpretation<br />

and miscommunication.<br />

For Reference<br />

With today’s reduction in workforce and budgets, and<br />

higher pressure on uptime, little time is allowed for comprehensive<br />

training in the workplace. As a result, more of those<br />

budgets is being spent on “fighting fires”. Much of this time<br />

and expense is attributable to failures due to lubricationrelated<br />

failures. The LGG is not intended to replace quality<br />

intensive training, such as that offered by organizations like<br />

NLGI and Noria Corporation, but rather The Guide serves as<br />

a supplement and reference for that information.<br />

NLGI has now published its fifth edition of the NLGI<br />

Lubricating Grease Guide (LOCCN: 84-61641; ISBN: 0-<br />

9613935-1-3) which contains nine chapters of easily<br />

accessible information covering topics from historical and<br />

technical aspects differentiating greases to the manufacture,<br />

testing, application and troubleshooting of lubricating<br />

greases. It has been the first source of technical information<br />

for anyone either entering the grease industry or involved in<br />

daily maintenance operations – as well as a regular reference<br />

for those of us who have been in the business for a while.<br />

Chapters of Insight<br />

The first four chapters give the reader a fundamental<br />

background of where grease comes from historically, what<br />

goes into making it, how it is tested for quality and<br />

performance, and how the various combinations of grease<br />

thickeners and base oils compare. Technically minded but<br />

chemically challenged folks will find that the chemistry of<br />

what goes into a grease is both accessible and sensible, and<br />

this is covered in a painless three or four pages. It is good to<br />

have a basic understanding of this material, even for<br />

mechanical-type personnel.<br />

The manufacturing chapter is interesting from the standpoint<br />

that there are quite a number of ways to produce the<br />

grease, and there are a variety of downstream processes<br />

possible. It’s almost as interesting as visiting an actual<br />

grease manufacturing plant in person. The chapter on<br />

testing is good reference as well, especially when you’re<br />

trying to decipher what a grease supplier is calling out on its<br />

technical data sheets.<br />

The following four chapters discuss when grease is used<br />

(vs. oils), which grease to use when, how to handle and<br />

dispense it, and some thoughts on troubleshooting problems.<br />

This is the “good stuff” for those of us who are<br />

actually specifying or choosing and using the grease. What<br />

will one thickener type do better or poorer than another (for<br />

example, calcium vs. lithium soap)? Which grease is a<br />

food–grade grease? What about water resistance? What are<br />

the principal uses of the different grease types?<br />

54 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


These chapters provide a good working background for the knowledgeable<br />

application of grease. This is followed by information on safe<br />

handling procedures and some useful reference material – including a<br />

glossary of terms and abbreviations of which I kept a copy tucked safely<br />

behind my pocket protector for several years. Very handy stuff!<br />

Continuing Education<br />

As stated earlier, there is no substitute for independent, qualified<br />

and experienced providers of information and education. If<br />

you’re reading this article, you are obviously already familiar with<br />

at the education Noria provides through its publications and seminars.<br />

NLGI provides another tool which is tailored to the grease<br />

industry and the proper formulation, manufacturing and application<br />

of lubricating greases. The NLGI Lubricating Grease Guide can<br />

also help solidify your learnings around grease lubrication and act<br />

as a primary reference for the future.<br />

About the Association<br />

The NLGI is a not-for-profit trade association, composed primarily of companies<br />

who manufacture and market all types of lubricating grease. NLGI promotes the<br />

technical advancement of grease lubrication, and contributes materially to greater<br />

production, increased machine life and a higher quality of machine performance<br />

through better lubrication. For more information, visit www.nlgi.com.<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 55


CERTIFICATION NEWS<br />

ICML Reaps<br />

Benefits of Conference<br />

BY SUZY JAMIESON, ICML<br />

From May 19 through 22, the International Council for<br />

<strong>Machinery</strong> <strong>Lubrication</strong> (ICML) participated in Noria’s<br />

very successful Lean, Reliable and Lubed <strong>2008</strong> conference in<br />

Nashville, Tenn. In addition to exhibiting and holding two<br />

certification exam sessions, the council had its annual board<br />

and committee meetings. The ICML Laboratory Lubricant<br />

Analyst committee held an ad-hoc meeting to discuss and<br />

develop work to propose to ISO TC108/SC5/WG4 on the<br />

upcoming standard 18436-5 – Condition Monitoring and<br />

Diagnostics of Machines – Requirements for Qualification<br />

and Assessment of Personnel – Part 5: Lubricant Laboratory<br />

Technician/Analyst.<br />

The findings of this meeting were later shared at the<br />

annual ISO TC/108/SC5/WG4 meeting, which was held in<br />

Kyoto, Japan, the following week. The council was fortunate<br />

for the support and participation of knowledgeable laboratory<br />

representatives from several different companies from<br />

across the globe.<br />

Labs<br />

The laboratories represented included Analysts Inc.,<br />

Caribbean Analytical Services (Trinidad), Caterpillar,<br />

CleanOil, Focus Laboratories (Thailand), Laboratorio Dr.<br />

Lantos (Argentina), MRG Corporation, PdMA, Solge<br />

(South Korea), Staveley Services, Southwest Research<br />

Institute, and Tekniker (Spain). The council would like to<br />

thank these companies for their pioneering vision and<br />

expert mentoring provided.<br />

Recognitions<br />

ICML also presented the <strong>August</strong>us H. Gill Award for<br />

Excellence in Oil Analysis and the John R. Battle Award for<br />

Excellence in <strong>Machinery</strong> <strong>Lubrication</strong>. These awards were<br />

created by the council to inspire companies to achieve worldclass<br />

status in their oil analysis and machinery lubrication<br />

programs. The criteria for each of these recognitions serve<br />

as a road map for aspiring companies, which are often<br />

mentored by past recipients.<br />

Gill Award<br />

This year’s recipients of both the Gill and Battle awards<br />

coincidentally came from the state of North Dakota, which<br />

speaks highly of the state for its “best in class” status. The<br />

2007 Gill was awarded to Coal Creek Station in Underwood,<br />

N.D.. Coal Creek is part of Great River Energy company. Kim<br />

Burkeland, Coal Creek’s chemical analysis technician,<br />

accepted the Gill Award on behalf of the station.<br />

Battle Award<br />

The 2007 Battle Award was awarded to Cargill Corn<br />

Milling in Wahpeton, N.D.. Preston Hatfield, plant maintenance<br />

manager, accepted the award on behalf of Wahpeton.<br />

He was accompanied by lubrication specialist and program<br />

lead analyst Clyde Hughes of Allied Reliability and Dorothy<br />

Onchuck, lubrication specialist from UGL Unicco Services.<br />

Receiving the Battle award caps a five-year effort by the<br />

Wahpeton Corn Milling Facility to improve equipment reliability<br />

through improved lubrication practices. The<br />

application for the award outlined the various improvements<br />

the plant has made over the past five years, including but not<br />

limited to:<br />

• Improved storage and handling practices<br />

• Innovative equipment setup to improve overall efficiency<br />

of lubrication tasks<br />

• Utilizing onsite oil analysis to asses equipment health and<br />

target equipment for remediation effort<br />

• Deployment of portable and bypass filtration to improve<br />

overall oil cleanliness and reduce oil consumption<br />

• Development of written procedures to govern the lubrication<br />

program<br />

56 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


• Training of site personnel in improved<br />

lubrication practices<br />

Team Effort<br />

“Team Wahpeton” is the motto of the<br />

Wahpeton facility, and this effort is demonstrated<br />

by the total integration of Cargill<br />

personnel along with embedded contractors<br />

such as Allied Reliability and UGL Unicco<br />

Services. These companies work together in a<br />

seamless effort to make this plant operate at<br />

peak efficiency and reliability.<br />

The Wahpeton facility demonstrates<br />

what may be accomplished when traditional<br />

barriers between a parent company and<br />

contracted service providers can be bridged<br />

to make the whole team a family unit. The<br />

Wahpeton plant also recently enjoyed recognition<br />

by receiving IndustryWeek magazine’s<br />

Best Plant and Cargill’s Best Plant awards<br />

for 2007.<br />

Nominations are Welcome<br />

Both awards are open to companies<br />

worldwide, independent of any involvement<br />

in the Council. A company does not need to<br />

be a member of ICML to apply. The council<br />

does not charge any fees to applicant<br />

companies and it does not nominate companies<br />

for the awards. Companies need to<br />

apply for the awards directly. Vendors and<br />

other industry practitioners may nominate a<br />

company and ICML will contact it to verify<br />

its interest in applying for one of the awards.<br />

Information on the council’s awards<br />

program, including the criteria for each<br />

award can be found at www.lubecouncil.org.<br />

Information on the oil analysis program at<br />

Coal Creek Station as well as Cargill<br />

Wahpeton’s lubrication program will be<br />

covered in this column in upcoming issues of<br />

<strong>Machinery</strong> <strong>Lubrication</strong>.<br />

Need to take an exam?<br />

ICML regularly holds exam sessions throughout the<br />

United States and the world. Upcoming dates and<br />

locations for ICML exams can be found at<br />

www.lubecouncil.org<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 57


BACK PAGE BASICS<br />

What’s Contaminating<br />

Your Oil?<br />

JEREMY WRIGHT<br />

During the last few months, I’ve noticed a slight misconception<br />

when speaking with clients. When I speak about<br />

contamination control, it is typically misunderstood as<br />

pertaining only to solid or particulate contamination. In this<br />

article, I would like to shed light on another, less mentioned<br />

form of contamination: moisture.<br />

States of Coexistence<br />

Moisture is the second-most-destructive contaminant<br />

found in machinery, next to particle contamination.<br />

Moisture can exist in oil in the following three states or<br />

phases:<br />

“The volume of water that will dissolve<br />

into the oil depends upon the oil’s base<br />

stock, condition, additive package,<br />

contaminant load and temperature.”<br />

Dissolved<br />

Contrary to what I was taught, oil and water do mix. The<br />

volume of water that will dissolve into the oil depends upon<br />

the oil’s base stock, condition, additive package, contaminant<br />

load and temperature. Typically, new, high-grade oils<br />

with minimal additive loads will hold little dissolved water.<br />

Conversely, oxidized, lower grade oil that is heavily additized<br />

can hold as much as 2,000 ppm water in the dissolved state.<br />

In this state, water is not visible in the oil.<br />

Emulsified<br />

Once the amount of water has exceeded the maximum<br />

level for it to remain dissolved, the oil becomes saturated. At<br />

this point, the water is suspended in the oil in microscopic<br />

droplets known as an emulsion. Emulsified water is often<br />

referred to as having a hazy appearance.<br />

Free<br />

Adding more water to an emulsified oil/water mixture will<br />

lead to a separation of the two phases, producing a layer of<br />

free water. This water separates from the oil due to inherent<br />

insolubility and the specific gravity difference between the<br />

two fluids. In most cases, free water is found at the bottom<br />

of tanks and sumps.<br />

How Moisture Affects Components<br />

In a lubricating system, the two most harmful phases are free<br />

and emulsified water. According to SKF, as little as 1/10th of a<br />

percent water in oil can reduce the life expectancy of a journal<br />

bearing by as much as 75 percent. For rolling element bearings,<br />

the situation is even worse. The main cause of this shortened life<br />

cycle is the weakening of the oil film strength. The weakened film<br />

leaves the component more susceptible to abrasive, adhesive<br />

and fatigue wear. Not only will water destroy the oil film<br />

strength, but both free and emulsified water under the extreme<br />

temperatures and pressures generated in the load zone of a<br />

rolling element bearing can result in instantaneous flash-vaporization,<br />

causing erosive wear to occur.<br />

How Moisture Affects the Lubricant<br />

Not only does water have a direct harmful affect on machine<br />

components, but it also plays a direct role in the oxidation<br />

(aging) of lubricating oils. The presence of water in a lubricating<br />

oil can cause the progress of oxidation to increase tenfold,<br />

resulting in premature aging of the oil, particularly in the presence<br />

of catalytic metals such as copper, lead and tin. Where free<br />

water accumulates in a system, microorganisms can grow. These<br />

microbes feed on the oil and decompose to form acids, which<br />

promote further oxidation of the oil.<br />

58 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>


Measuring Contamination<br />

There are five basic test methods to determine the moisture<br />

content of a lubricating oil. These methods range from a<br />

simple apparatus to a more complex chemical test or slightly<br />

more expensive percent saturation probe test.<br />

Crackle<br />

The most basic is the crackle test. In this test, a hot plate<br />

is held at 320°F (130°C) and a small drop of oil placed in the<br />

center. Any moisture present in the oil is reflected in the<br />

number of bubbles observed as the water vaporizes.<br />

Depending on the lubricant, relatively few small bubbles indicate<br />

approximately 500 to 1,000 ppm (0.05 to 0.1 percent)<br />

water. Significantly more bubbles of a larger size may indicate<br />

around 1,000 to 2,000 ppm water, while an audible crackling<br />

sound indicates moisture levels in excess of 2,000 ppm. The<br />

crackle test is sensitive only to free and emulsified water.<br />

Pressure Cell<br />

Another simple on-site test is the use of a pressure cell,<br />

where the sample is prepared with a chemical reagent<br />

(calcium hydride) and placed in a container and shaken<br />

vigorously. A change of pressure within the cell is monitored<br />

to determine if free water is present. The cost of this type of<br />

product is relatively low, although the operational costs must<br />

be considered with regard to the reagents, as well as the<br />

health and safety issues of these reagents.<br />

Relative Humidity Sensor<br />

A third type of on-site screening test for water is a relative<br />

humidity sensor. The sensor uses a thin film capacitance grid<br />

that can determine the amount of moisture permeating<br />

through the film. The advantage of this method is its relatively<br />

low running costs and that it can be permanently<br />

mounted on critical plant equipment to provide real-time<br />

monitoring.<br />

Fourier Transform Infrared Spectroscopy<br />

Aside from the on-site screening methods, another<br />

commonly used method to screen for water is Fourier<br />

Transform Infrared Spectroscopy (FTIR). This test is sensitive<br />

to free, emulsified and dissolved water; however, it is<br />

limited in precision to a lower detection limit of approximately<br />

1,000 ppm. This is adequate for some applications<br />

<strong>Machinery</strong> <strong>Lubrication</strong> machinerylubrication.com <strong>July</strong> - <strong>August</strong> <strong>2008</strong> 59


BACK PAGE BASICS<br />

but insufficient for typical industrial applications.<br />

Commercial laboratories that use<br />

this method often report that less than 0.1<br />

percent volume of water is present in<br />

the sample.<br />

Karl Fischer<br />

The most precise method for determining<br />

the amount of free, emulsified and dissolved<br />

water in a lubricating oil is the Karl Fischer<br />

moisture test. When used correctly, the Karl<br />

Fischer test is capable of quantifying water<br />

levels as low as 10 ppm, or 0.001 percent,<br />

and should be the method of choice when<br />

more exact water concentrations need to<br />

be known.<br />

Controlling Contamination<br />

Once detected, the root cause of the<br />

ingress of the moisture should be investigated.<br />

If detected early enough and the oil’s<br />

physical and chemical properties are not<br />

compromised, the water can be removed and<br />

the oil kept in service. Following are a few<br />

methods for this removal:<br />

Settling<br />

Free water can be removed from oil by<br />

providing a good settling location. This is<br />

typically provided in the form of a bottom<br />

sediment and water bowl (BSWB). Settling,<br />

however, will not remove dissolved or emulsified<br />

water.<br />

Centrifugal Separators<br />

The settling process can be accelerated<br />

when the forces of gravity are magnified using<br />

a centrifuge. While more effective than<br />

regular gravity separation, centrifugal separation<br />

fails at removing dissolved and<br />

emulsified water.<br />

Vacuum Distillation<br />

In a vacuum dehydrator, oil is put under a<br />

vacuum and the temperature is elevated. This<br />

effectively vaporizes the water from the oil at<br />

a temperature that does not severely harm<br />

the lubricant.<br />

Polymeric Filters<br />

These filters look like typical, spin-on or<br />

cartridge-style filters, but they contain a<br />

filter media impregnated with super<br />

absorbent polymer. The polymer absorbs<br />

free and emulsified water and forms a gel.<br />

Water is a major cause of lubricant<br />

failure, component failure and poor<br />

machine reliability. Like all contaminants, it<br />

is important not only to recognize its presence,<br />

but also to take steps to control or<br />

eliminate the source of water ingression. If<br />

possible, moisture levels should be kept at<br />

an absolute minimum. Whether you choose<br />

to install desiccant-style breathers, improve<br />

seals, or to use a centrifugal filter or a large<br />

vacuum dehydration unit, reducing the level<br />

of water in all types of equipment can<br />

dramatically extend the life of the lubricant<br />

and the machine.<br />

About the Author<br />

Jeremy Wright’s role as senior technical consultant<br />

for Noria Reliability Solutions (NRS) has him furthering<br />

his skills as a lubrication specialist by teaching on-site<br />

seminars for a variety of clients and conducting<br />

<strong>Lubrication</strong> Process Design (LPD) consulting services<br />

for several industries.<br />

Jeremy is a certified <strong>Machinery</strong> Lubricant Analyst<br />

(MLA) Level I and Level II and <strong>Machinery</strong> <strong>Lubrication</strong><br />

Technician (MLT) Level I by the International Council<br />

for <strong>Machinery</strong> <strong>Lubrication</strong> (ICML). In addition, he is a<br />

Certified Maintenance and Reliability Professional<br />

(CMRP) by the Society for Maintenance and<br />

Reliability Professionals (SMRP). Contact Jeremy at<br />

jwright@noria.com.<br />

References<br />

1. Mark Barnes. “Water - The Forgotten Contaminant.”<br />

Practicing Oil Analysis magazine, <strong>July</strong> 2001.<br />

2. Drew Troyer and Jim Fitch. Oil Analysis Basics, 2001<br />

revision. Tulsa, Oklahoma: Noria Corporation.<br />

Would You Like to Contribute?<br />

Are you a technical expert? We want to publish<br />

your lubrication article in <strong>Machinery</strong> <strong>Lubrication</strong>.<br />

To submit a technical article, review the guidelines<br />

at www.machinerylubrication.com and send<br />

article to jkucera@noria.com.<br />

60 <strong>July</strong> - <strong>August</strong> <strong>2008</strong> machinerylubrication.com <strong>Machinery</strong> <strong>Lubrication</strong>

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