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FROM THE FIELD

Understanding Engine Oil

Bypass FiltrationWhen combined with a full-flow filter, bypass filtration offers the

benefits of lower wear generation rates, lower oil consumption,higher combustion efficiency and longer oil life.

VIEWPOINT

Evaluating the Direction

of Your Lubrication ProgramDo you know where you are going with your lubrication program?

Setting a realistic goal of where you want to be is the best way to

increase the chances for success.

LUBE-TIPSOur readers provide excellent advice on a host of lubrication-relatedissues, including a better approach for greasing bearings.

HYDRAULICS AT WORK

Carefully Consider Isolation Valves

on Hydraulic Pump Intake LinesFind out when a more expensive ball valve is mandatory, when the

generally cheaper butterfly type is the only choice and when you

should fit neither ball valve nor butterfly valve.

More 36 PRODUCT SUPERMARKET38 CROSSWORD PUZZLER41 BOOKSTORE

Editorial Features

32 GET TO KNOW40 NOW ON MACHINERYLUBRICATION.COM

Departments

18 PRODUCT NEWS34 TEST YOUR KNOWLEDGE

INDUSTRY FOCUS

New Advances in Wear Debris Analysis The recent advances in wear debris particle analysis cater to the n

for portable equipment that is easy to use while also addressing level of skill and training of onsite personnel.

CONTAMINATION CONTROL

Effective Varnish Removal

from Turbine Lubrication Systems The mitigation of varnish-related problems in turbine systerequires not only cleaning up the varnish precursors from fluid and the soluble deposits from the wetted surfaces, but a

controlling their formation.

CERTIFICATION NEWS

ICML and ACIMA

Sign Cooperation Agreement The International Council for Machinery Lubrication (ICMrecently formalized its cooperation with the Costa Rican Assotion of Maintenance (ACIMA), signaling a new era for Costa Ric

lubrication practitioners.

BACK PAGE BASICS

How Rolling Element Bearings Work Understanding the basics of how rolling element bearings work atheir design can help you achieve added reliability at your plant.

July - August 2012

Contents4COVER STORYThe Hidden Dangers of Lubricant Starvation

Lubricant starvation is an almost silent destroyer. While there are telltale signs, they generally aren’t recognized

or understood.


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Is your engine’s oil lter performing toyour expectation? Do you even know

the performance of your lter? Most peopledon’t, and if they did, they would be appalled.

Some of the best full-ow engine lters onthe market perform at a capture efciency of50 percent at a particle size of 10 microns andabove. That’s a beta ratio of 2 for those of youkeeping score, and these are considered “good”in terms of full-ow engine ltration. Incomparison, a beta ratio of 1,000 would be considered “good” interms of industrial hydraulic ltration. Why is there such a perfor-mance difference? The following factors contribute to the variance:

Physical SizeOften limited by physical size, engine oil lters are relatively

small when compared to their industrial counterparts. This smallsize coincides with less lter media surface area through which topass the lubricant.

Pressure Differential The pressure differential is the change in pressure from the inlet to

the outlet side of the lter. If the pressure differential is too high, avalve will open, allowing the oil to bypass the lter. All engine oil ltersor heads are equipped with a bypass valve. This valve is needed so theengine does not become starved of oil as the lter clogs with debris.

Flow RateIn most engine designs, oil must ow through the lter before

entering the engine components. Therefore, the lter must be ableto handle 100 percent of the ow rate needed to feed the moving

components of the engine.

Media Pore Size The media pore size is the major determi-

nant in how efcient and how small of a

particle the lter can remove.When these factors are combined, a

problem arises. The physical size is usually

constrained by design. The lter can’t be too

large because of all the other components that

we are trying to t under the hood. The ow

rate must be high enough to feed all the lubri-

cated components. This means you can’t make the pore size too

small or it will raise the pressure differential and the bypass valve

will open, effectively rendering the lter useless.

There are a few things you can do to remedy this problem. Enter

bypass ltration. Bypass ltration systems take 5 to 10 percent of

the ow that would have gone to feed the engine and cycle it

through an ultra-efcient lter and back to the sump.

With bypass ltration, the ow rate can be greatly reduced,

allowing for a much smaller pore size while retaining a normal pres-

sure differential. The result is much cleaner oil being returned to the

sump. Smaller soot suspension and polar insolubles that are not

controlled by the full-ow lter can now be taken out of the system.

Understanding ENGINE OIL Bypass FILTRATION

FROM THEFIELD

JEREMY WRIGHT | NORIA CORPORATION

O i l F i l t e r s

2 | July - August 2012 | www.machinerylubrication.com

Bypass filtration offers the benefits of lower wear genera-tion rates, lower oil consumption,

higher combustion efficiencyand longer oil life.

of lubrication professionals usebypass filtration systems at theirplant, based on a recent poll at

machinerylubrication.com

65%

http://www.machinerylubrication.com/http://www.machinerylubrication.com/


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PUBLISHERMike Ramsey - [email protected]

GROUP PUBLISHERBrett O’Kelley - [email protected]

EDITOR-IN-CHIEF Jason Sowards - jsowards@nor ia.com

SENIOR EDITOR Jim Fitch - [email protected]

TECHNICAL WRITERS Jeremy Wright - [email protected] Oviedo - [email protected]

Josh Pickle - jpickle@nor ia.comWes Cash - [email protected]

CREATIVE DIRECTORRyan Kiker - [email protected]

GRAPHIC ARTISTSSteve Kolker - [email protected] Cervantes - [email protected]

Julia Backus - [email protected]

ADVERTISING SALES Tim Davidson - [email protected], ext. 224

MEDIA PRODUCTION MANAGERRhonda Johnson - [email protected]

CORRESPONDENCE You may address article s, case studies,special requests and other correspondence to:

Editor-in-chiefMACHINERY LUBRICATIONNoria Corporation1328 E. 43rd Court • Tulsa, Oklahoma 74105Phone: 918-749-1400 Fax: 918-746-0925E-mail address: jsowards@nor ia.com

MACHINERY LUBRICATION Volume 12 - Issue 4 July-August 20(USPS 021-695) is published bimonthly by Noria Corporation, 13243rd Court, Tulsa, OK 74105-4124. Periodicals postage paid at TuOK and additional mailing ofces. POSTMASTER: Send addchanges and form 3579 to MACHINERY LUBRICATION, P.O. B47702, Plymouth, MN 55447-0401. Canada Post International Publtions Mail Product (Canadian Distribution) Publications MAgreement #40612608. Send returns (Canada) to BleuChip Intetional, P.O. Box 25542, London, Ontario, N6C 6B2.

SUBSCRIBER SERVICES: The publisher reserves the right to acceptreject any subscription. Send subscription orders, change of address all subscription related correspondence to: Noria Corporation, P.O. 47702, Plymouth, MN 55447. 800-869-6882 or Fax: 866-658-6156

Copyright © 2012 Noria Corporation. Noria, Machinery Lubricatand associated logos are trademarks of Noria Corporation. All rigreserved. Reproduction in whole or in part in any form or medwithout express written permission of Noria Corporation is prohibitMachinery Lubrication is an independently produced publication

Noria Corporation. Noria Corporation reserves the right, with respecsubmissions, to revise, republish and authorize its readers to use the and articles submitted for personal and commercial use. The opiniof those interviewed and those who write articles for this magazinenot necessarily shared by Noria Corporation.

CONTENT NOTICE: The recommendations and information providedMachinery Lubrication and its related information properties do purport to address all of the safety concerns that may exist. It is the respsibility of the user to follow appropriate safety and health practices. FurthNoria does not make any representations, warranties, express or implregarding the accuracy, completeness or suitability, of the informationrecommendations provided herewith. Noria shall not be liable for any iries, loss of prots, business, goodwill, data, interruption of business, for incidental or consequential merchantability or tness of purposedamages related to the use of information or recommendations provid

Machinery

Lubrication

When combined with a full-ow lter, bypass

ltration offers the benets of lower wear genera-

tion rates, lower oil consumption, highercombustion efciency and longer oil life.

In a case study performed by General Motors

and published by the Society of Automotive Engi-

neers (SAE), it was determined that engine service

life could be extended eight times when 5-micron

ltration is implemented vs. the standard

40-micron ltration.

Obviously, having cleaner oil is better for thereliability of the engine. There’s an old saying that

oil doesn’t wear out; it just gets dirty. Although

there is some validity to the idea that dirtier oilwill “age” quicker than clean oil, the engine oilwill have a nite life. It will need to be changed

eventually no matter how clean you keep it.

While it’s true that a system can remove the

majority of suspended soot, wear debris and dirt,

the oil and additives are still being decomposed

by oxidation and nitration. The depletion of

these additives will ultimately be the reason for

the oil change. The system should slow down the

rate of this depletion, but it cannot eliminate it.

Acids, fuel and coolant are just a few of the

contaminants that bypass ltration cannot

address. They too can shorten the life of the oil.If you are shopping for one of these systems, it

is vital that you do your homework. Not all bypasssystems are created equal, and there is a plethora

of marketing material out there to make you feel

thoroughly confused. Keep in mind that while

testimonials may seem impressive, they are not

scientic proof. Make sure the manufacturer has

SAE and ISO testing to back up its claims.When installed and maintained properly, a

bypass system can provide great benefits. Justbe sure to ask all the right questions and havea firm grasp on the concept before settling ona system.

About the Author Jeremy Wright is vice president of technical services

for Noria Corporation. He serves as a senior technicalconsultant for Lubrication Program Developmentprojects and as a senior instructor for Noria’s Funda-mentals of Machinery Lubrication and AdvancedMachinery Lubrication training. He is a certied main-tenance reliability professional through the Societyfor Maintenance and Reliability Professionals, andholds Machine Lubricant Analyst Level III and MachineLubrication Technician Level II certications throughthe International Council for Machinery Lubrication.

Contact Jeremy at [email protected].

Oil filters can be tested in a variety of ways, but one of the most common methods is the beta ratio

test. This test incorporates online particle counters positioned upstream and downstream of the filter,

a continuous flow of test contaminant into the main sy stem reservoir and oil flowing through the filter.The beta ratio is calculated by dividing the number of particles larger than a certain size upstream of

the filter by the number of particles of the same size downstream of the filter. For example, you may have

a beta ratio or a beta sub 5 (meaning pa rticles larger than 5 microns) equal to 10. This means 10 particles

upstream of the filter would be divided by 1 downst ream of the filter. In other words, for every 10 particles

coming in, one gets th rough.

If you have a higher beta ratio, say a beta ratio of 100 or a beta sub 5 equal to 100, for every 100 particles

coming into the filter larger than 5 microns, one makes its way through.

Every filter will have multiple beta

ratios. There could be a beta ratio for

2 microns, 5 microns, 10 microns, 50

microns, 100 microns, etc.

You can also use the beta ratio to

calculate capture efficiency, which is the

average performance over the fi lter’s life,

with the following formula :

((Beta – 1)/Beta) x 100

As an example, a beta ratio of 10 would

yield a capture efficiency of 90 percent:

((10 – 1) / 10) x 100 = 90 percent

Therefore, 90 percent of the part icles

larger than 5 microns are removed by a

filter that has a beta ratio of 10.

The Beta Ratio Test

July - August 2012 | 3

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M L COVER STORY

4 | July - August 2012 | www.machinerylubrication.com



7/53www.machinerylubrication.com | July - August 2012 | 5

For those who strive for lubrication-enabled reliability (LER), more than 95

percent of the opportunity comes from paying close attention to the “Big Four.”

These are critical attributes to the optimum reference state (ORS) needed to achieve

lubrication excellence. The “Big Four” individually and collectively inuence the state of

lubrication, and are largely controllable by machinery maintainers. They are well-

known but frequently not well-achieved. The “Big Four” are: 1. Correct lubricant selection

2. Stabilized lubricant health

3. Contamination control

4. Adequate and sustained lubricant level/supply The rst three of the “Big Four” have beneted from considerable industry atten-

tion, especially in recent years. Conversely, the last one has gone relatively unnoticed yet

is no less important. Therefore, it will be the central focus of this article.

Over the past few decades, researchers and tribologists have compiled countless

listings that rank the chief causes of machine failure. We’ve published many of these inMachinery Lubrication magazine. The lists ascribe the causes of abnormal machine wear

to the usual suspects: contamination, overheating, misalignment, installation error,

etc. There’s typically a lubrication root-cause category that is a catch-all for one or

more causes that can’t be easily specied or named. I’ve seen terms used like “inade-

quate lubrication” and “wrong lubrication.”

Understandably, it is difcult for failure investigators and analysts to trace back theexact sequence of events beginning with one or more root causes. Evidence of these

causes is often destroyed in the course of failure or in a cover-up during the cleanup and

repair. Having led several hundred such investigations over the years, I’ve learned that

one root cause in particular is too often overlooked — lubricant starvation.

Although most everyone knows about this in principle and realizes the common

sense of adequate lubricant supply, it is frequently ignored because many typical forms

of lubricant starvation are largely hidden from view. For instance, who notices the

quasi-dry friction that accelerates wear each time you start an automobile engine? This

is a form of lubricant starvation. It’s not a sudden-death failure, but it is a precipitous

wear event nonetheless. Each time controllable wear goes uncontrolled, an opportu-

nity is lost to prolong service life and increase reliability.

The

Hidden Dangers of Lubricant Starvation BY JIM FITCH, NORIA CORPORATION

of lubrication professionals haveseen the effects of lubricant

starvation in the machines at theirplant, according to a recent survey

at machinerylubrication.com

81%

http://www.machinerylubrication.com/http://www.machinerylubrication.com/http://www.machinerylubrication.com/


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COVER STORY

The Nature of Lubricant StarvationMachines don’t just need some lubricant or any lubricant.

Rather, they need a sustained and adequate supply of the rightlubricant. Adequate doesn’t just mean dampness or the nearbypresence of lubricant. What’s dened as adequate varies somewhatfrom machine to machine but is critical nonetheless. High-speed

equipment running at full hydrodynamic lm has the greatest lubri-cant appetite and is also the most punished when star ved. Machinesrunning at low speeds and loads are more forgiving when lubesupply is restricted. Even these machines can fail suddenly whensevere starvation occurs.

The table below illustrates how lubricants reach frictionalsurfaces in numerous ways.

There are six primar y funct ions of a lubricating oil. These arefriction control, wear control, temperature control, corrosioncontrol, contamination control and transmittance of force andmotion (hydraulics). Each of these functions is adversely inu-

enced by starvation conditions. The worst would be friction, wearand temperature control. Even partial starvation intensies theformation of frictional heat. It also slows the transport of that

heat out of the zone. This is a compounding, self-propagatingcondition that results in collapsed oil lms, galling, adhesive wearand abrasion (Figure 1).

In the case of grease, starvation-induced heating (from friction)of the load zone accelerates grease dry-out, which escalates starva-tion further. Heat rapidly drains oil out of the grease thickener,

causing volatilization and base oil oxidation, all of which contrib-utes to hardening and greater starvation.Lubricating oil needs reinforcement, which is lost when ow

becomes restricted or static. Flow brings in bulk viscosity forhydrodynamic lift. In fact, lack of adequate lubricant supply isfunctionally equivalent to inadequate viscosity from the stand-point of lm strength.

Oil ow also refreshes critical additives to the working surfaces. This reser ve additive supply includes anti-wear additives, frictionmodiers, corrosion inhibitors and others. Lubricant starvationproduces elevated heat, which rapidly depletes additives.

Next, we know that wear particles are also self-propagating.

Particles make more wear particles by three-body abrasion,surface f atigue and so on. Impaired oil ow inhibits the purging ofthese particles from the frictional zones. The result is an acceler-ated wear condition.

Finally, moving oil serves as a heat exchanger by displacing local-ized heat generated in load zones outward to the walls of the machine,oil reservoir or cooler. The amount of heat transfer is a function of theow rate. Starvation impairs ow and heat transfer. This putsincreasing thermal stress on the oil and the machine.

Common Signs of StarvationWhen you’re encountering chronic machine reliability problems,

think through the “Big Four” and don’t forget about No. 4. It may

not be the type of oil, the age of the oil or even the contaminationin the oil, but rather the quantity of oil. How can you know? Thechart on page 8 reveals some common signs of lubricant star vation.

Lubricant Starvation Examples by Machine TypeLubricant starvation can happen in a number of ways. Most are

controllable, but a few are not. The following abbreviated list iden-ties how lubricant starvation occurs in common machines.

Starved Engines• Dry Starts — Oil drains out down to the oil pan when the

engine is turned off. On restart, frictional zones (turbo bear-ings, shaft bearings, valve deck, etc.) are momentarily starvedof lubrication (Figure 2).

• Cold Starts — Cold wintertime conditions slow the movementof oil in the engine during start-up. This

can induce air in the ow line due to cold-

temperature suction-line conditions.

• Low Oil Pressure — This can resultfrom numerous causes, including

worn bearings, pump wear, sludge

and extreme cold. Oil pressure is the

motive force that sends oil to the

zones requiring lubrication.

MEANS OF

LUBE SUPPLY

EXAMPLE

APPLICATION(S)

HOW SUPPLY IS

CONTROLLED

Grease that isdesigned to stay in

place near where it’sneeded

Electric motor bearings,pillow block bearings and

hinge pins

Preventing grease dry-out by correct grease

selection and optimizingregreasing interval andfrequency

Gravity flow appliedby oil-feed devices

Mechanical feed systemssuch as drip lubricators,slingers, oil rings andsplash mechanisms

Regularly checking the funct ionali ty of thedevice in use

Cross-flow lubrication by forcing oil through the frict ionalzone (by pumping)

Dry-sump circulatingsystems, hydraulicsystems, oil mist, etc.

Frequently verifying that the minimal flow rate issustained at each lubepoint in the system

Spray lubrication Open gears, circulat ing

gears and large chaindrives

Spray volume, fre-

quency, aim and spread

Bath or floodlubrication

Rolling element bearingsand gears that are par-

tially or fully submergedin the lubricant

Oil level control, control-ling foam, sludge andsediment

LubricantFilm

BoundaryContact

ubricantFilm

FullFilm

Weldingand

Galling

Figure 1. Starvation Illustrated

Good Oil Supply Impaired Oil Supply Dry Friction and Wear



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• Dribbling Injectors — Fuel injector problems can

wash oil off cylinder walls and impair lubricationbetween the piston/rings and the cylinder wall.

• Clogged Spray Nozzles and Orices — Nozzles andorices direct oil sprays to cylinder walls, valves andother moving components. Sludge and contami-nants are able to restrict oil ow.

Starved Journal and Tilting-Pad Thrust Bearings• Oil Groove Problems — Grooves and ports channel oil to the

bearing load zones. Grooves become clogged with debris orsludge, restricting oil ow.

• Restricted Oil Supply — Pumping and oil-lifting devices canbecome mechanically faulty. This also may be due to low oil

levels, high viscosity, aeration/foam and cold temperatures.

• Sludge Dam on Bearing Leading Edge — Sludge can build upon the bearing’s leading edge and restrict the oil supply.

Wet-Sump Bearing and Gearbox Starvation• Oil Level — Many wet-sump applications require

critical control of the oil level (Figure 3).

• High Viscosity — Many oil-feed mechanisms (oil

rings, slingers, splash feeders, etc.) are hamperedby viscosity that is too high (wrong oil, cold oil,etc.). Gears can channel through thick, cold oil,interfering with splash and other feed devices.

• Aeration and Foam — Air contaminationdampens oil movement and impairs the perfor-mance of oil-feed devices (Figure 4).

• Non-horizontal Shafts — This can cause dragon oil rings and may interfere with slinger/ingerfeed mechanisms.

• Bottom Sediment and Water (BS&W) — SumpBS&W displaces the oil level. On ver tical shafts,the bottom bearing can become completelysubmerged in BS&W.

• Defective Constant-Level Oilers — This may bedue to plugged connecting pipe nipples,mounting errors (tilted, cocked, mounted onwrong side, etc.), wrong level setting, emptyreservoir, etc. (Figure 5).

• Defective Level Gauge Markings — Levelgauges should be accurately calibrated to thecorrect oil level.

COVER STORY

STARVATIONISSUE

HOW IT IS DIAGNOSED OR CONFIRMED

BY INSPECTION BY LABORATORY ANALYSIS

Low oil levelin a wet sump

(bath) system

Inspect oil level (level gauge), foamyoil, excessive sludge or sediment,

shaft seal smoke, acoustics/noise,heat gun, inspect constant-level oilers(low supply, plugged connector)

High oil viscosity, premature oiloxidation, sludge, varnish poten-

tial, fr iction polymers, adhesivewear debris, tempered particles,black iron-oxide particles

Low oil flowin cross-flowapplication

Heat gun, thermography, flow meters,erratic flow meter movement, inlinesight glass flow, aerated or foamy oil,elevated bearing-metal temperature,high drain-line temperature

Premature oil oxidation, sludge,varnish potential, frictionpolymers, adhesive wear debris,

tempered particles, black iron-oxide particles

Inadequateregreasevolume and/orfrequency

Heat gun, thermography, acoustics/ noise, purged hardened grease,hardened grease observed on rebuild,defective injectors/autolubers,

depleted grease supply, cake-lockproblems, grease gun backpressure,shaft seal smoke

Low in-service oil content ofgrease, high grease consistency,premature oil oxidation, frictionpolymers, adhesive wear debris,


Faulty lubelifting orgravity-feeddevice

Wrong oil level (too high/low), coldrunning, high viscosity, defectivelifter/feed device, aeration/foam,depleted oil supply reservoir, oilring wobble

Premature oil oxidation, sludge,varnish potential, frictionpolymers, adhesive wear debris,


Ineffectivelube spray

Inspect spray pattern, stream, target,volume and frequency

Premature oil oxidation, sludge,varnish, friction polymers,adhesive wear debris, temperedparticles, black iron-oxide particles

Figure 2. Dry Engine Starts

Critical oil level

(submerge bottom tooth completely)

Optimum gear dip level is influenced

by gear type, gear size, speed, viscosity

and oil film strength. Always consult

gear manufacturer.

Even oil levels just slightly too low cansharply reduce lubricant scuffing, load

capacity (shorten gear life), increase

oil temperature (shorten oil life) and

increase oil foaming.

Figure 3. Common Splash Gear Drive

Common Signs of Lubricant Starvation



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COVER STORY

• Level Gauge Mounting and Viewing Issues — These may behard to see, goosenecks, fouled gauge glass, gauge vent prob-lems, etc. (Figure 6).

Starved Dry-Sump Circulating Systems• Restricted Oil Returns — Plugged or partially plugged oil

returns will redirect oil ow away from the bearing or gearbox

being lubricated. Sometimes called drip-and-burn lubrication,

the condition is usually caused by sludge buildup or air-lockconditions in the gravity drain lines returning to the tank.

• Worn Oil Pump — When oil pumps wear, they lose volumetricefciency (ow decay results).

• Restricted Pump Suction Line — Strainers andpickup tubes can become plugged or restricted.

This can aerate the uid, cause cavitation and leadto loss of prime.

• Clogged/Restricted Oil Ways and Nozzles — Oil-feed restric-tions due to sludge, varnish and jammed particles can starvebearings and gears (Figure 7).

• Entrained Air and Foam — Oil pumps and ow meters performpoorly (or not at all) when sumps become contaminated with air

(Figure 4).

• Lack of Flow Measurement — Components sensitive to oilsupply require constant oil ow measurement.

• Defective or Miscalibrated Flow Meters — Flow meters,depending on the type and application, can present a range of

problems regarding calibration.

• Low Oil Pressure — Oil follows the path of least resistance.Line breaks and open returns starve oil from higher resistanceow paths and the machine components they serve.

Starved Spray-Lubed Chains and Open Gears• Defective Auto-lube Settings — This relates to correctly setting

the lube volume and frequency.

• Defective Spray Targets/Pattern — The oil spray needs tofully wet the target location. Spray nozzles can lose aim andbecome clogged (Figure 8).

• Gummed Chain Joints — Many chains become heavily gummed,which prevents oil from penetrating the pin/bushing interface.

Starvation from Grease Single- and Multi-Point Auto Lubrication• Wrong Regrease Settings — Regreasing settings should enable

adequate grease replenishment at each lube point.

• Cake-Lock — This occurs when grease is being pumped. Undercertain conditions, the grease thickener movement is restricted.Oil ows, but the thickener is log-jammed in a line or compo-nent passage (Figure 9).

• Defective Injector Flow — This is due to wrong injector set tings

or restricted injector displacement.

Figure 5. Mounting Errors of Constant-Level Oilers

Figure 6. What is wrong with this picture?

Figure 7. Plugged Oil Flow

Tilted Cocked

Varnish and sludge

Figure 4. How Aeration Retards Oil Supply




• Restricted Line Flow — Exceedingly

long lines, narrow lines, numerousbends, ambient heat or cold, etc., can

lead to partial or complete blockage

of grease ow.

• Single-point Lubricator Issues — These include malfunctioning

lubricators from various causes.

Starvation fromManual Lubrication Issues• Grease Gun Lubrication —

This may include an inaccuratevolume calibration, a faulty

grease gun mechanism, the

wrong relube frequency, an incorrect

relube volume or an improper relube

procedure.

• Manual Oil Lubrication — This wouldinclude the wrong relube frequency,

volume or procedure.

• Lube Preventive Maintenance (PM)— Missed PMs may be due to sched-

uling, management or maintenance

culture issues.

The Crux of the ProblemLubricant starvation is an almost silent

destroyer. While there are telltale signs, they

generally aren’t recognized or understood.

Of course, there are vary ing degrees of star-

vation. Complete starvation is sudden and

blatant. However, more moderate partial

starvation is what tends to go unnoticed

until failure. Then, other suspect causes

(the bearing, lubricant, operator, etc.) may

be falsely blamed.

Precision lubrication supply is a funda-

mental attribute of the optimum reference

state and is included in any engineeringspecication for lubrication excellence. It’s

one of the “Big Four” and thus is overdue

for signicant attention.

About the Author Jim Fitch has a wealth of “in the trenches ”

experience in lubrication, oil analysis,

tribology and machinery failure investiga-

tions. Over the past two decades, he has

presented hundreds of courses on these

subjects. Jim has published more than 200

technical articles, papers and publications.He serves as a U.S. delegate to the ISO

tribology and oil analysis working group.

Since 2002, he has been director and board

member of the International Council for

Machinery Lubrication. He is the CEO and

a co-founder of Noria Corporation. Contact

Jim at [email protected].

Figure 8. Correct Lubricant SprayPatterns on Open-Gear Tooth Flanks

Figure 9. Cake-Lock Grease Starvation

1. Identify the required lube supply or level to optimize reliability.

2. Establish and deploy a means to sustain the optimized supply or level.

3. Establish a monitoring program to verify the optimized supply or level is

consistently achieved.

4. Rapidly remedy non-compliant lube supply or level problems.

4 Keys to Solving Starvation Problems

Using Proactive Maintenance

http://www.machinerylubrication.com/http://www.machinerylubrication.com/mailto:[email protected]://www.fluidline.com/mailto:[email protected]://www.machinerylubrication.com/



Are we there yet? With summer break now upon us,this question likely will be asked countless times on

family vacation trips across the nation. Planning for these tripstypically includes asking questions such as where do we want

to go, what is our budget, what are the things we need to getthere and what can be eliminated. Obviously, the goals mustbe realistic. Tough decisions and sacrices will be requiredfrom all involved, but the end result will be well worth the effort.

During my travels to various industries, I’ve found that someworkers lack a clear plan as to where they are going. They may knowthat they are there to perform “work,” but beyond that there is littlecommunication/direction between the departments as to where andwhen they will get there. Imagine putting your family in the car and just saying, “OK, let’s go.” While some might suggest to “just do it,”this motto doesn’t seem to translate well in our professional careers.

Can you answer the “are we there yet” question? If not, perhapsyou need to ask yourself if you even know where you are going. It may

be time to re-evaluate the direction of your lubrication program.If you have had the opportunity to attend any of Noria’s Funda-

mentals of Machinery Lubrication courses, then you should be veryfamiliar with the goal of lubrication excellence. Hopefully, you havegained an understanding of why it is important to keep lubricants

clean, cool and dry, as well as the effects of contamination onequipment health. My experience is that most people’s intentions

are good when they start. If they would put the same amount oftime and effort into striving for lubrication excellence as they do intheir family’s summer vacation, they would be successful.

Do you know where you are going with your lubrication program?Are you tracking results and addressing opportunities to improve?Do you have attainable, realistic goals? Do you have the right people

EVALUATING theDIRECTION of YOUR

Lubrication PROGRAM

PETE OVIEDO JR. NORIA CORPORATION

VIEWPOINT

L u b r i c a t i o n P r o g r a m s

1) Set targets for all lubricating oils and hydraulic fluids.

2) Use vendor specifications as ceiling levels only.

3) Set life-extension (benefit-driven) targets (e.g., significantly

cleaner than before).

4) Consider machine design, application and operating influences.

5) Make it a personal decision, because you are the one paying the

cost of failure, not the machine supplier, oil supplier, filter

supplier, bearing supplier or oil analysis lab.

5 Tips for Setting Target

Cleanliness Levels

10 19/16/13 18/15/12 17/14/12 16/13/11 15/12/10 14/11/9 13/10/8 12/10/8 11/9/7 10/9/7

9 19/16/13 19/16/13 18/15/12 17/14/11 16/13/10 15/12/10 14/11/9 13/10/8 11/9/7 11/9/7

8 20/17/14 20/17/13 19/16/13 18/15/12 16/13/11 15/12/10 14/11/9 13/10/8 12/9/8 12/9/7

7 20/17/14 20/17/14 19/16/13 18/15/12 17/14/11 16/13/10 15/11/9 14/11/9 13/10/8 12/10/8

6 21/18/15 21/18/14 19/16/13 18/15/12 17/14/11 16/13/10 15/12/9 14/11/9 13/10/8 12/10/8

5 21/18/15 21/18/15 20/17/14 19/16/13 18/15/12 17/14/11 16/14/11 15/13/11 14/11/10 13/11/9

4 22/19/16 22/19/16 20/17/14 19/17/14 18/15/13 17/14/11 16/14/11 15/13/10 14/12/9 13/11/9

3 22/19/16 22/19/16 21/18/15 20/17/14 19/16/13 18/15/12 17/14/11 16/14/11 15/13/10 14/12/9

2 23/20/17 23/20/17 22/19/16 21/18/15 20/17/14 19/16/13 18/15/12 17/14/11 16/14/11 15/13/10

1 24/20/17 23/20/17 22/19/16 21/18/15 20/17/14 19/16/13 19/16/12 18/15/11 17/14/11 16/14/11

1 2 3 4 5 6 7 8 9 10

Target Cleanliness Grid

Contaminant Severity Factor (CSF): Sensitivity of Machine to Contaminant Failure

R e l i a b i l i t y P e n a l t y F a c t o r ( R P F ) : C o s t , S a f e t y a n d

B u s i n e s s I n t e r r u p t i o n P e n a l t y f r o m F a i l u r e




with the right attitudes in the right positionsto improve the opportunities for success?Once again, tough decisions and sacriceswill be required from all involved, but the endresult will be well worth the effort.

Lubrication excellence can be achieved.

However, many factors can distract you from thegoal. You may have started a lubrication program but now have cometo the realization that you need to re-evaluate or change the directionof the program. This can become confusing and frustrating, especiallywhen results are not achieved as expected.

There are a few steps you can take to increaseyour chances for a successful lubricationprogram or to get back on track. Many times,however, we tend to put the “cart before thehorse.” Setting a realistic goal of where you wantto be is the best method to increase the chancesfor success. If you don’t know where you aregoing, how do you know when you get there?

Most kids can only sit in a car for so long beforethey become agitated. Likewise, most reliabilityand lube technicians can become frustratedwith just going through the motions, especiallywith so many having become educated andunderstanding the importance of lubrication.

Let’s start by setting a realistic goal forcontamination control and establishing cleanli-ness targets. These levels should reectreliability goals. This can be achieved by consid-ering the reliability penalty factor and thecontaminant severity factor. This will help to

set a contaminant goal that is based on yourspecic facility’s goal. You also need to take specic actions to

reach the goal. This means selecting the properlter and capture efciency to achieve the target.Be sure to measure the contaminant levelsfrequently. Remember, what gets measured getsdone. Make appropriate changes as necessary.Setting this goal will help your departmentanswer the “are we there yet” question.

About the AuthorPete Oviedo Jr. is a senior technical

consultant with Noria Corporation, focusing

on machinery lubrication and training. He

has more than 20 years of experience with

machinery and rotating equipment, as well as

an understanding of laser alignment, balancingrotating equipment, thermography, magnetic particle and ultrasonic

aw detectors. Need help with your lubrication program? Contact Pete

at [email protected].

of lubrication professionals say theirplant has not yet achieved lubricationexcellence, based on survey results

from machinerylubrication.com

67%

http://www.machinerylubrication.com/http://www.machinerylubrication.com/mailto:[email protected]://www.klsummit.com/mailto:[email protected]://www.machinerylubrication.com/



If you already use vibration-monitoring equipment with

“spike energy,” gSE or other high-frequency detection tech-

nology, you can optimize the quantity of grease added to a bearing

by running your monitoring equipment while adding grease. Whenthe overall level of the signal

drops suddenly and notice-

ably, grease has reached the

bearing. Stop adding more.Using this approach saves

those on limited budgets from

having to buy additional specialized

greasing equipment with monitoring ability.

Advice for Overheating HydraulicsIf the hydraulic system is overheating on your mobile equipment,

it may prove useful to scan the entire

machine for the source. For example,

a machine that was gradually buildingheat in the hydraulic system started at

an operating temperature of 130degrees F and rose to 160 degrees F.

After the thermography scan wascomplete, it became clear what the

problem was. The auxiliary pump to

the main pump was failing. This

resulted in the oil reservoir main-taining a temperature above 200

degrees F. The reason the operators

saw only a temperature of 160 degrees

F was due to a faulty gauge.

Use Caution with Heat Exchangers There are many reducers in an industrial environment that

require heat exchangers. Along with the benets of heat exchangers

comes the possibility of water leaks. Determine if the heat exchanger

is truly necessary by noting the temperature of the reducer when theheat exchanger is valved off. If the reducer temperature is below the

oil’s highest temperature runability, it may be a good idea to valve

off the water to deter a possible water leak. If the reducer can’t

operate without the heat exchanger, then oil analysis should beperformed more often. It is important to frequently conduct oil

analysis on water-cooled equipment because a leak in the cooling

system can be catastrophic to the equipment.

Modifying Sight Glass

Improves VisibilityOn equipment with vented oil

tube sight glasses, it is sometimeshard to determine the oil level. Thismay be due to poor lighting or a dustyenvironment. On the next inspectionof the equipment, try removing thetube and glass. Clean the inside of thetube with a degreaser, then color theinside with a white or bright colormarker that is compatible with youroil. A felt-tip white metal markingstick works great because it allowsyou to get inside the tube channel.Equipment oil levels will be easier todetect with the lighter background.

A Variation on the Crackle Test Another method of performing the crackle test to detect the

presence of water in oil involves using a small portable electric ovenburner. Place 1 ounce of the contaminated oil sample in a glass

bottle on the burner. The bottle should not be capped. As thewater-contaminated oil sample is heated, the water will heat,bubble and then begin to evaporate. If the oil is contaminated onlywith water, the oil will look like new oil after all of the water isevaporated. This process takes about 5 minutes or less and easilyconrms the presence of water. As with all heat-related tests, useprotective equipment to protect your face, hands and body whenperforming this test.

How to Store Grease CorrectlyStore tubes of grease vertically, not on their sides. This will

minimize the amount of oil loss from bleeding, keeping the

containers and storage area in better condition.

M L LUBE TIPS

The “Lube Tips” section of Machinery Lubrication magazine

features innovative ideas submitted by our readers. Additional tips

can be found in our Lube-Tips e-mail newsletter. If you have a tip

to share, e-mail it to us at [email protected]. To sign up for the

Lube-Tips newsletter, visit www.machinerylubrication.com and

click on the “Newsletters” link at the top.

A BETTER APPROACH FOR

GREASING BEARINGS

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18/53

At a recent hydraulic maintenance workshop, I was asked formy opinion on isolation valves on pump intake lines and

whether a more expensive ball valve is mandatory as opposed to the

generally cheaper buttery type. At the root of this question is thenegative effect of turbulence in the pump intake line. The argumentfor using a ball valve as an intake-line isolation valve is that when it’sopen, the full bore of the valve is available for oil ow. So if you havea 2-inch ball valve installed in a 2-inch intake line, when the valve isopen, it’s as if it isn’t there at all (from the oil’s point of view at least).

On the other hand, a buttery valve is not full bore. Even whenfully open, the buttery remains in the bore and presents a partialrestriction, which is irregular in shape. This causes turbulence,which can result in dissolved air coming out of solution in the intakeline. If this happens, these air bubbles will collapse when exposed topressure at the pump outlet. In other words, a buttery valve maycause gaseous cavitation.

So which is best: a ball or buttery valve? Well, like a lot of issuesin hydraulics, it depends. In a perfect world, I would always choosea ball valve ahead of a buttery valve. For intake-line diameters upto 3 inches, there’s virtually no cost penalty involved in doing so.

However, when you get into 4-, 6- and 8-inch diameters, ball valvesare very expensive in comparison to their buttery counterparts. Theyalso take up a lot more space, particularly in overall length. So in amobile application, for example, not only may the cost of a large-diameter ball valve be prohibitive, but there also may not be enoughspace between the tank outlet and the pump inlet to install it.

There is a third alternative. Many people wrongly believe intake-line isolation valves are essential, when in reality they are not, butfor a few exceptions.

The rst question that pops up in response to this is how can

the pump be changed out if there is no isolation valve on the

intake line. There are two answers to this. First, if the pump has

failed catastrophically and you are doing things “right,” the oilshould be pumped out of the tank using a lter cart and into clean

drums or other suitable container. Then the tank should be thor-

oughly cleaned, the pump changed out, and the oil (assuming it is

still serviceable) pumped back into the tank using a lter car t.

The common objections to this are: “Oh, we don’t have time

for that!” or “We don’t have 10, 20 or however many clean drums

sitting around.” A work-around for those who don’t want to do

the job right is to cap all penetrations into the tank headspace

and connect an industrial vacuum cleaner to the tank breather

penetration. Switch on the vacuum cleaner while the pump is

changed out, and then when the debris from the previous pump

failure causes the replacement pump to fail, repeat the exercise.

Of course, there are exceptions, such as if there’s more than

one pump sucking from the same tank or it’s just not practical to

pump say 3,000 gallons of oil out of the tank. Sometimes intake-

line isolation valves are a necessity. If this is the case, it’s wise to

make sure they have proximity switches to prevent the pump(s)

from being started when the valve(s) are closed.

My preferred approach is to t neither ball valve nor

buttery valve, if you can get away with it. If you must have

one, use a ball valve if cost or space isn’t an issue. However, if

either of these things is a problem, then a buttery valve is the

only choice.

There are many applications where buttery valves are used as

pump-intake isolation valves. Large hydraulic excavators are a

common example. They have multiple pumps sucking out of big

tanks through large-diameter intake lines and not much space —

HYDRAULICSAT WORK

BRENDAN CASEY

H y d r a u l i c s

Many people wrongly believe intake-line isolation valves are

essential, when in reality they are not, but for a few exceptions.

16 | July - August 2012 | www.machinerylubrication.com||||

1. The cost of the component is saved.

2. The distance between the tank and the pump can be

shortened.

3. The pump can never be start ed with the intake isolation

valve closed.

3 Benefits of Not Installing anIntake-line Isolation Valve

CAREFULLY Consider

ISOLATION Valveson HYDRAULIC Pump Intake Lines




all the ingredients that rule out the more

preferred options (no valve or ball valve).

I don’t recall ever seeing a pump off a

large hydraulic excavator that didn’t have at

least some cavitation erosion damage, which

in this application could be regarded as fair

wear and tear. Could this cavitation damagebe attributed to turbulence caused by the

buttery valve? Sure it could, but a lot of

other things may be responsible for it as well.

The only way to know for cer tain would be to

compare two pumps operating under the

same conditions — one with and one without

a buttery valve installed.

About the AuthorBrendan Casey is the founder of Hydraulic-

Supermarket.com and the author of Insider Secrets

to Hydraulics, Preventing Hydraulic Failures, Hydraulics

Made Easy and Advanced Hydraulic Control . A uid

power specialist with an MBA, he has more than

20 years of experience in the design, maintenance

and repair of mobile and industrial hydraulic

equipment. Visit his Web site at www.Hydraulic-

Supermarket.com.

of lubrication professionals preferball valves for hydraulic pump

intake lines, according to a recentsurvey at machinerylubrication.com

75%

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R O D U C T N E

W S

18 July - August 2012 | www.machinerylubrication.com

SYNTHETIC MOTOR OIL The new Monolec Tetra-Syn Engine Oil from Lubrication Engineers Inc. is a

100-percent-synthetic motor oil for gasoline engines. It exhibits low volatility andlow viscosity shear characteristics while also providing low- and high-tempera-ture performance. A premium additive package has been incorporated in thenew oil, including the Monolec wear-reducing additive, to deliver fuel economy,protect emission systems, keep engines clean and keep deposits to a minimum.Available in SAE 5W-20 and 5W-30 grades, Monolec Tetra-Syn Engine Oil caneven improve fuel economy in many newer engines.

Lubrication Engineers Inc.

www.LElubricants.com

800-537-7683

HOSE REELHannay Reels’ N500 Series

spring-rewind dual hose reelis designed for efficient hosehandling in grease and oilapplications. The compactframe and narrow mountingbase allow easy installation in

almost any location. Equippedwith a heavy-duty spring motorwith self-contained rewind powerand a four-way roller assembly,the N500 Series handles single¼-inch or 3/8-inch I.D. hose. Anon-sparking ratchet assemblylocks the reel at the desired hoselength. A pull on the hose unlocks the reel for retraction, whilethe declutching arbor prevents damage from reverse winding.

Hannay Reels

www.hannay.com

877-467-3357

FOOD-GRADE LUBRICANTSSprayon’s new NSF H1-rated food-grade lubricants have been treated withantioxidants and additives to specificallyaddress the performance and applicationneeds of the food-processing industry.

Consisting of fine food-grade base stocksincluding synthetics, renewable oils andsilicones, the new lubricants offer heavier

load pressures, resistance to water washout,lower flammability ratings and widertemperature ranges to preserve and protectequipment, prevent costly breakdowns andensure maximum performance.

Sprayon

www.sprayon.com

800-SPRAYON

AIR-OIL SYSTEMS The new line of Oil Streak air-oil systems by Bijur Deli-mon provide a simple-to-use “plug-and-play” formatthat is designed to perform in the most demandinghigh-speed spindle lubrication applications. The air-oil mixing valves blend precise amounts of air and oil,thanks in part to special oil injectors created specificallyfor spindle oil applications.

Bijur Delimon

www.bijurdelimon.com

800-631-0168

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21/53 www.machinerylubrication.com | July - August 2012 19

BEARING CHECKERKittiwake’s new MHC Bearing Checker is a small handheld

device that can provide instant indication of machinery condi-tion. Based on the detection of high-frequency activity thatis naturally generated by deterioration in rotating machinery,the instrument’s distress parameter removes the need for machine-specific interpretations. If the distress parameter is greater than 10,the user knows there is a problem. A decibel level is also provided, givingan indication of the overall noise of the bearing. Each measurement takesapproximately 10 seconds and requires no setup, previous history or knowledge of machinedesign details. The unit is powered by an internal rechargeable battery.

Kittiwake

www.kittiwake.com

713-255-7255

DIRT ALARM INDICATORS The MS17, MS18 and MS19 electrical dirt alarm indicatorsfrom Schroeder Industries are engineered to provide anaccurate indication of the need to change an element inorder to help maintain fluid cleanliness. They can be usedwith a wide range of hydraulic filters and are suitable formobile and industrial applications requiring the connec-tion of indicators with a static working pressure of lessthan 6,000 psi. The crimped body design eliminates theneed for the four bolts used in the design of existing electri-cal dirt alarm indicators, reducing cost and assembly time.

Schroeder Industries

www.schroederindustries.com

800-722-4810

ELECTRIC TENSIONING PUMP The ZUTP1500 Electric Tensioner Pump from Enerpac features a two-stage pump design to provide high flow at low pressure for fast systemfills, as well as controlled flow at high pressure for safe and accurateoperation. Engineered for the wind turbine market, the new pump incor-porates a remote-controlled electric valve and universal motor withouta hydraulic intensifier for hassle-free operation of bolt tensioners andhydraulic nuts in remote locations. The ZUTP1500 includes a durable,lightweight aluminum roll cage and reservoir with a sheet-metal frontpanel to guard the pump from the rigors of the worksite.

Enerpac

www.enerpac.com

262-293-1600

METALWORKING FLUIDSCimcool has introduced a new line of metalworking fluidsdesigned to meet the challenges of the tube and pipe industry.Cimmill fluids are formulated to increase productivity by up to 20percent while offering good lubricity, rust protection and sumplife. The fluids also provide excellent foam control, improved toollife and increased uptime during critical roll forming, cut-off andthreading operations. The Cimmill line of product covers a widerange of applications including the most severe.

Cimcool

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888-CIMCOOL

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INDUSTRY FOCUS

BY DR. VIOLET LEAVERS, V4L PARTICLES LTD.

T The harsh work environments in which some industrial equip-

ment is situated can lead to short life cycles and unpredictablefailures, such as those found in mining or offshore oil and gasindustries. While manufacturers may offer and honor time-based warranties, they cannot predict accurately the lifespan ofthe equipment. Moreover, replacement of equipment underwarranty by the manufacturer does nothing to mitigate the costof unscheduled downtime and lost revenues.

A solution to this problem lies with the various uid andparticle condition monitoring tests that convey informationabout the current mechanical state of a system. In the front lineof these is the collection and analysis of wear debris particlestaken from a component’s lubricating or power transmissionuid. Wear debris analysis is so important because sampling isrelatively simple to execute, the test is non-destructive and it can

give a vital early warning of incipient component failure.

Particle Sizing and Counting HardwareParticle counts can be determined using optical instruments.

The rst of these methods is to use a microscope. Par ticles areprecipitated from uid samples, which are taken from thecomponent’s lubrication system, by draining through a lterpatch. Particles are then interactively sized and counted manu-ally using a microscope. However, because of its labor-intensivenature, this method was replaced by automatic particle counters(APCs) in the 1960s.

First-generation APCs contain a laser light source and a

detector, which are separated by an optical cell. The oil sample

ows through the cell, and when a particle passes through it, anarea of light is obscured. The detector senses the loss of light andoutputs a voltage. The voltage pulse generated increments theparticle count, and the height of the pulse is used to determinethe size of the particle.

These APCs have the disadvantage of not being able to distin-guish between multiple particles, and because they are “blind” tothe shape of the particle, they are only able to report size in terms ofa projected area equivalent diameter. That is, size is dened as thediameter of the disc with an area equivalent to the area of theparticle’s shadow. This method can lead to errors because the esti-mated projected area equivalent diameter is a function of the shape

of the particle. In other words, the size of the particle is increasinglyunderestimated as the shape becomes more elongated. In partic-ular, long, thin particles will be systematically undersized to thepoint where they may slip into a size range smaller than their actualsize indicates or even disappear from the count all together.

A second generation of APCs has emerged that operatesusing micro-second duration-pulsed lasers. This has the effect offreezing the image of the particles present in the optical cell. Thelight sensor associated with rst-generation APCs is replaced bya charge-coupled device (CCD) sensor. In this way, the system isable to collect the silhouette images of multiple particles. Imageprocessing is then used to count and size the particles.

Various contaminants such as varnish or bers have opticalproperties that make them invisible to APCs. These contaminantscan build up to critical levels without being detected by the APC.

The ASTM D7596-11 standard test method for automaticparticle counting and particle shape classication of oils using adirect-imaging integrated tester gives a list of 11 possible sourcesof error when using a second-generation APC. A relatively highlevel of skill and experience not generally available onsite wouldbe needed to detect or control these er rors.

Innovative Particle Imaging HardwareNew technology has recently become available that solves

many of the practical limitations imposed by the traditional

New Advances inWear Debris Analysis

Wear debris analysis is simple to

execute, the test is non-destructiveand it can give a vital early warningof incipient component failure.



23/53

http://www.hydraulicparticlecounter.com/



design of the microscope when viewing and capturing images ofboth macroscopic and microscopic particles. The new tech-nology is dedicated to optimizing the lateral and axial resolutionavailable at the magnications and resolutions required toreproduce images in an electronic form, whether that is for datastorage, printing in reports or for on-screen viewing. In this way,

images can be generated in which the depth of focus and eld ofview are optimized for viewing macroscopic and microscopicparticles at the same magnication.

With the new technology, it is possible to acquire sharplyfocused images over a much wider range of magnications andresolutions than when using a traditional microscope andwithout resorting to motorized stages or specialized software inorder to create a wider eld of view or extended depth of focus.

The image above shows a one-shot image of an oxidized particleon a lter patch. Without such a sharp image allowing the surfacedetail to be seen, this particle might be mistaken for a brass/copperfatigue particle, whereas it is a hybrid particle with striations associ-ated with severe sliding and colors indicating heating.

This new technology can be implemented in such a way as to be

sufciently stable and compact to be used onsite. It also generatesimages at a size that can be transmitted electronically if more expertadvice from a remote specialist laboratory is required.

Automatic particle sizing and counting software has alsobeen developed for use with the new imaging technology. Thissoftware is uniquely “plug-and-play” and does not require theuser to input subjective thresholds in order to distinguishparticles from the background image. This makes it ideal foronsite use where the end user may not have the skill or trainingnecessary to set image-processing thresholds. The new particlesizing and counting hardware and software technology is alsocompliant with ISO 4406 and 4407, NAS 1638 and SAE

ARP598 standards.

From Images to InformationA new concept in wear debris particle analysis has been developed

to specically meet the needs of onsite technicians. This new softwareis compliant with and uses the particle classications and nomencla-ture given in the ASTM D7684-11 standard guide for the microscopiccharacterization of particles from in-service lubricants.

The new software provides the onsite maintenance profes-sional with access to an expert knowledge base of thefundamentals of wear debris analysis in order to assist in theidentication of transitions between benign, active and criticalwear patterns. By interacting with the software, the end user canaccess the following information:

• The wear debris mode to which a selected particle belongs

• The processes and conditions contributing to a particularwear mechanism

• Information about equipment-specic wear modes

• Wear debris analysis using equipment-specic baselines

• When and how to correlate the data from other cleanlinesstests with wear debris mode classication in order to identifytransitions between normal, active and critical levels of wear

• An alert when equipment health is critical and the onsiteprofessional needs to call for remote support

These features make the new software ideally suited for onsite

situations where the level of training and skill of the attendanttechnician may require substantial support.In conclusion, it is clear that the uid and particle condition

monitoring needs of the onsite maintenance professional differsignicantly from the resources required by the lab-based expert. The recent advances in wear debris particle analysis cater to thisneed for portable equipment that is both easy to set up and usewhile also addressing the variable level of skill and training ofonsite personnel.

About the AuthorDr. Violet Leavers is an internationally acknowledged expert in

machine vision and image processing. She currently works with V4L Parti-

cles Ltd. and can be reached via e-mail at [email protected].

INDUSTRY FOCUS

This Macro-2-Micro one-shot image of an oxidizedparticle on a filter patch shows surface detail thatwould not be visible using a microscope without

extended focus capability.

This image of magnetic plugdebris seen at 40x magnifica-tion includes a particle that an

inexperienced technician mightmistake for brass or copper.

Image-2-Information softwareveals that because the

particle has a non-uniformsurface color, it is not brass

copper but instead a heateparticle, indicating early

stages of lubricant starvatio

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http://www.dexsil.com/




BY KHALID FAROOQ, PALL CORPORATION

IIn recent years, the power-generation industry has seen anincrease in varnish-related problems in combustion turbines. This increase is attr ibuted to higher operating temperatures,smaller uid reservoirs, more peaking and cyclic service, highlyrened base stocks that have lower solvency for varnish precur-sors, and a more widespread use of ner ltration that causesmore electrostatic charging of the turbine oil.

The solvency of varnish in turbine oil is temperature depen-dent, with the transition point being in the range of 130 to 135degrees F. The temperature frequently falls below this thresholdin the hydraulic control section of turbines, resulting in the

formation of deposits on control valves. The most problematic aspect of varnish contamination of aturbine lubrication and control system is that the materialplates out on servo-valve surfaces, leading to valve sticking,and plugs the last-chance lters (LCFs) that are part of theservo-valve assembly.

LCFs made with sintered metal or ne screens provide aconvenient surface for the formation of varnish because of theirlocation in the low-ow, colder hydraulic control section. Lowertemperature promotes varnish formation because of the lowersolubility of the material at lower temperatures, which causes itto come out of solution and deposit on the lter’s metal surface.

Filters made with glass-ber media normally are not pluggedby varnish. Full-ow lters as ne as 6 microns are known to haveno varnish-related premature plugging, although the uid mayhave elevated levels of varnish-forming material. The plugging ofmetal pencil lters but not the larger glass-ber lters is likelydue to the difference in the interaction of the varnish materialwith metal versus the glass ber, the cooler temperatures in thehydraulic section and the lower ow velocity.

In addition to the servo-valve deposits, varnish precursors formdeposits on mechanical seals, Babbitt sleeve bearings, thrust-bearing pads and orices, resulting in restrictions. When thesedeposits develop on heat exchanger and reservoir walls, reduced

heat transfer and higher temperatures are likely to occur.

What is Varnish? Varnish is the thin, insoluble lm deposit that forms on uid-

wetted surfaces inside a turbine lube system, including bearingsand servo valves. The material is comprised of a wide range of oiladditives and high molecular weight thermo-oxidative uidbreakdown compounds that have limited solvency in the base

uid. These compounds are polar in nature and begin to migratefrom the base uid to the wetted surfaces over time, based onthe system and uid conditions and their polar afnities.

Initially, the surfaces show a gold/tan color, building to darkergum-like layers that eventually develop into a hard, lacquer-likematerial. The chemical compositions of these insoluble materialsvary depending on the turbine operating conditions, the uidbase stock and additive type.

How Varnish FormsAll turbine oils create insoluble materials, even under normal

operating conditions. The rate of generation is accelerated under

Effective VarnishRemoval from TurbineLubrication

Systems

Varnish deposits on the spool of a servo valve.

This photomicrographshows varnish mate-

rial on an analysismembrane (0.45-

micron porosity) at100x magnification.

The same varnishmaterial is shown at

1,000x magnificationusing a scanning

electron microscope.



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equipment in many industrial applications has shown this

ltration media to eliminate lter damage and signicantly

lower charge generation compared with the typical glass-ber

ltration medium.

Varnish Removal Technologies The currently available solution for removing varnish from

turbine lubrication uids can be divided into three categories —

electrostatic purication, chemical cleaning/ushing and

adsorption by a disposable media.

The elec trostatic method, operating in kidney-loop mode of f

the main tank, subjects the uid to an electrical eld, which

causes the varnish precursors to charge and agglomerate into

larger particles that are then captured by a lter mat or attractedto a charged, disposable surface.

There are several designs based on variants of the elec tro-

static charging principle to accomplish this goal. The

electrostatic-type devices are reported to remove varnish

precursors from the uid phase, and as the uid is cleaned up,soft varnish deposits from surfaces are re-entrained in the uidand removed, thus resulting in the cleaning up of deposits accu-mulated over a period of time.

Since the removal of varnish from systemcomponents is a relatively slow process, these

devices are recommended to be operated over along period of time or to be installed permanently. They are repor ted to be sensitive to elevated mois-ture levels in the uid and also to the presence ofhigh levels of metal wear particles.

The chemical cleaning/ushing method forremoving varnish utilizes cleaning chemicals thatare typically circulated through the system todislodge varnish from components. These chemi-cals soften and dissolve the insoluble materials,and the ushing action suspends the hard depositsin the uid, which are then removed with the uid

when it is drained from the system. This process isusually performed for several hours or severaldays, depending on the system size and the ex tent

of the varnish build-up on components.Once the ush and chemical treatment is completed, the

system must be ushed again with an appropriate ushing uid toremove residual chemicals and to ensure no contamination ndsits way into the new lubricating oil. Although this process is moreintensive, it does allow for quicker removal of varnish deposits,especially in a large system. It also requires close monitoring andentails lost production due to the turbine being out of operation.

The adsorption method utilizes adsorbent media with a large

surface area and high void volume, relatively low uid ux and insome cases an electro-chemical afnity for varnish precursors.Many materials can be used as adsorbents, including compressedcellulose, cotton linters and macro-porous media such as resinbeads, Fuller’s earth, activated carbon, etc.

There are two types of adsorption: physisorption and chemi-sorption. Physisorption, also called physical adsorption, is aprocess in which the adsorbent material and the adsorbatemolecules (varnish precursors) do not form chemical bondsarising from a chemical reaction but are bonded by weak electro-static forces arising from induced dipole moments such as vander Waals forces. The electronic structure of the adsorbate does

not change upon adsorption. Because of its chemical structure,varnish molecules are believed to be attracted to the adsorbentthrough weak molecular forces such as hydrogen bonding.

A ltration medium based on physisorption, called a VarnishRemoval Filter (VRF), has been developed. This ltration mediumis a composite consisting of a cellulose ber matrix and othermaterials that give it a high-void volume and an open-ber matrix. The resin-bonded, open-ber matrix provides high permeability,which is necessary for the uid to come in contact with the largeber surface area for the absorption of the varnish precursors. Thespecially formulated binder resins give the lter media high afnityfor the polar varnish precursors, resulting in high removal ef-

ciency and retention of the material suspended in the uid phase.

Fluid charging with standard glass-fiber andelectrostatic dissipative (ESD) filter elements.

* Varnish rating determined by Herguth Laboratories. ** Filtered at 160 degrees F.*** The varnish rating of filtrate is estimated. The initial

values are by Analysts Inc.

DETAILSINITIALVARNISH RATING

FILTEREDVARNISH RATINGTURBINE FLUID ID

GE Frame 7B* A 59 0

GE Frame 7FA* B 47 0

GE Frame 7FA* B 47 22**

GE Frame 7FA C 62 15***

Alstom GT8C D 34 11

Alstom GT24B E 85 15***

MHI 501 (G) F 58 15***

Laboratory Test Results with Varnish Removal Filter Medium




The VRF medium was tested in a labo-ratory using samples of degraded uidobtained from operating turbines thathad reported high levels of varnish. Thevalues (shown in the table on page 28)were taken after single-pass ltration at

ambient room temperature, except forthe third test, which was conducted at auid temperature of 160 degrees F. Thehigher varnish rating of the ltrate sampleat a higher temperature indicates lowervarnish removal performance, likely dueto the higher solvency of the varnishprecursors in the uid and lower absor-bency at an elevated temperature.

Tests were also conducted to asses theeffect on the uid’s additives as a result ofthe treatment with the VRF medium. The

results indicated essentially no change inthe level of aromatic amine and hinderedphenol between the unltered sampleand the sample that was ltered 20 times. The absence of any depletion of this addi-tive suggested that the VRF medium hadno noticeable adverse effect on the uid.

Following successful laboratory vali-dation of the ltration medium, a skidincorporating the VRF lter modules andthe associated control system was testedon two operating turbines. The treat-

ment of the turbine lubrication systemsentailed installation of the skid in akidney-loop mode, taking the uid fromone end of the reservoir and returning itto the opposite end continuously. Bothtrials ran uninterrupted with minimaloperator intervention and utilized oneset of three VRF modules for each trial. The removal and retention of varnishmaterial by the ltration medium wasindicated by the staining of the mediumby the varnish material.

One signicant difference betweenthe two turbines treated with the VRFwas the level of varnish deposits in thelubrication systems. The inside of themain ow lter housing on the Alstomturbine lubrication system indicated thepresence of a heavy brownish coating ofvarnish material. No such deposits wereobserved in the GE Frame 7FA turbinelubrication system.

Following clean-up of the Alstomturbine, the VRF skid was removed, and

the plant re-installed the electrostatic-type

Aromatic Amine = 99%, Hindered Phenolic >100%Results of the analysis conducted on a new, unused fluid sample.

Field trial results on an Alstom turbine.

Field trial results on a GE Frame 7FA turbine.

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cleaner that had been used before the VRFtreatment. A sample from the Alstom turbinewas obtained about six months after the VRFtreatment and was found to have elevatedvarnish levels. The GE Frame 7FA turbine wassampled two months after the VRF treatment

and had low varnish levels similar to that atthe time of the termination of the treatment. The reason for the recurrence of the high

varnish level in the Alstom turbine is believedto be the heavy varnish deposits in the systemthat were not completely removed during theeight weeks of the uid treatment, although

the varnish precursors in the uid phase werereduced to very low levels. The difference inthe uid clean-up rate, which was longer inthe case of the Alstom turbine, and the slightincrease after the initial decrease in the

varnish level can also be attributed largely tothe presence of heavy varnish deposits in theAlstom turbine lubrication system.

The two eld trials revealed that theamount and type of varnish deposits in thelubrication system had a bearing on howquickly the uid could be rid of the varnishmaterial and for how long after the clean-upit would remain free of elevated varnish

levels. There are also variables other than the level of deposits,such as the type of the varnish material, temperature, dutycycle, uid type, state of the deposits, etc., that inuence therate of varnish removal from the uid and the dissolution of thedeposits back into the uid.

In summary, the mitigation of varnish-related problems inturbine lubrication and hydraulic control systems requires notonly cleaning up the varnish precursors from the uid and thesoluble deposits from the wetted surfaces, but also controllingtheir formation. The absorptive lter technology discussed isengineered to remove the polar varnish precursors and hasproven to be effective in the removal of the varnish material fromturbine lubrication systems.

In addition, lter-induced electrostatic charging can becontrolled with the utilization of specially designed, charge-dissi-pative ltration media that produce much lower uid charging,thus mitigating the associated uid damage while providing thene levels of ltration required by modern turbines.

This Varnish Removal Filterskid was used to treat two

operating turbines.

These images show a used VRF medium

as received from the field (left), rinsedwith hexane (center) and rinsed withtoluene (right).

Pictured aboveis an unused

VRF medium.

Varnish deposits werefound inside the filterhousing of the Alstom

turbine lubrication system.

SALES @BIJURDELIMON.COM

UNITED STATES CHINA | FRANCE | GERMANY | UNITED KINGDOM | IRELAND | INDIA | SPAIN | RUSSIA

CORPORATE HEADQUARTERS 2100 GATEWAY CENTRE BLVD, SUITE 109, MORRISVILLE, NC 27560

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Q What types of training have you taken to get to your

current position?

A I was able to get started in the industry when I earned my bach-elor’s degree in mechanical engineering.

Q What professional certifications have you attained?

A I have Vibration Analyst Category 1 and Machine LubricantAnalyst Level 1 cer tications.

Q Are you planning to obtain additional training or

achieve higher certifications?

A I am working to get Vibration Analyst Category 2 and MachineLubrication Technician Level 2 certications.

Q What’s a normal work day like for you?

A My day starts by reviewing the current schedule for the day,making sure there have been no process upsets that may require ourattention and then bringing the crew up to speed with pertinentinformation. I start one hour before they arrive. Once the team isout in the facility servicing our equipment and executing ourrounds, I work on verifying the accuracy of our listed routes,updating as necessary, planning equipment upgrades, preparingfor machine maintenance downtime, and developing and executing

capital projects.

Q What is the amount and range of equipment that you

help service through lubrication/oil analysis tasks?

A We have about 5,000 driven pieces of equipment and several

thousand rotating pieces of equipment that are driven either byconveyor belts, gear trains or ropes. My department is responsible

for all routine lubrication work on this equipment and also invasiveinspections of gear and grid-type couplings, as well as universal-type drive shafts. I estimate that we have about 50,000 lubricatedcomponents for which we are responsible. We have 95 percent of

them well-documented and are working on the rest.

Q What lubrication-related projects are you currently

working on?

A We designed and are now installing a centralized lubrication-dispensing station that will eliminate nine satellite dispensinglocations that do not utilize proper contamination control orergonomic considerations. This project will strategically locate

four bar-tap type dispensing areas around the mill with 3-micronltration of our three most widely used products. The dispensingstations will service all ve of our paper machines. The projectinvolves 1,500 feet of 1½-inch pipe and three 1,000-gallon reser-voirs. We’ve been able to do this economically with some creativityan

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