fix the weak link- sampling

8/11/2019 Fix the Weak Link- Sampling

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2 www.TESTOIL.comInww.TESTOIL.com |@testoil1

WHYPULLOILSAMPLES

Oilanalysisisaquickandeasywayto

gaugethehealthofequipmentbylooking

atwhat'sintheoil.Samplingandanalyzing

oilonaregularbasisestablishesabaseline

fornormalwearandcanhelpindicate

whenabnormal

wear

or

contamination

is

occurring.Inaddition,oilanalysiscan

indicateiftheoilisstillfitforservice.Isan

oilchangereallynecessary?Alotof

moneycanbesavedinextendingoil

changeouts.

Oilthathasbeeninsideanyrotating

equipmentforaperiodoftimereflectsthe

conditionoftheequipment.Becauseoilis

incontactwithinternalcomponents,any

microscopicwearparticlesor

contaminantsfoundinthemachinewill

alsoshowupintheoil.Theseparticlesare

sosmalltheywillremainsuspendedintheoil.

Byidentifyingandmeasuringthese

particulates,yougetanindicationofthe

equipmentwearrateandofanyexcessive

contamination.Usingoilanalysiswill

identifycomponentwear,lubricant

conditionsand

overall

component

operatingconditions.

WhyIsOilAnalysisImportant?

Preventequipmentfailure

Selecttestingthatmonitors

equipmenthealthand

identifiespotential

catastrophicconditions

Extendequipmentlife

Selecttestingthatmonitorsoil

contaminationandequipment

wearrates

Extendlubricantlife

Selectteststhatmonitor

lubricantserviceability

Management,operations,

engineering,andfinancial

personnelshouldadoptthe

conceptthat:Maintenance

DoesntCost,ItPays.

AISESteelTechnology

Magazine


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WHYISPROPERSAMPLINGIMPORTANT?

Samplingisthemostimportantpartofany

lubeanalysisprogramandthequalityof

yoursamplesisvitaltothesuccessofyour

program. Allofthesophisticatedoil

analysistools,techniquesanddiagnostic

processesare

meaningless

ifthe

oil

samplefailstoeffectivelyrepresentthe

actualconditionoftheoilinservice.

PullingARepresentativeSample

Proper

oil

sampling

is

critical

to

an

effectiveoilanalysisprogram.Withouta

representativesample,youroilanalysis

programwillfail.Therearetwoprimary

goalsinobtainingarepresentativeoil

sample.

Thefirstgoalistoensurethatthelocation

youarepullingfromwillberepresentative

oftheoilinthesystem.Thisinformation

relatestosuchcriteriaascleanlinessand

drynessoftheoil,depletionofadditives,

andthepresenceofwearparticlesbeing

generatedbythemachine.

Thesecondgoalistominimize

contamination.It

is

important

to

make

surethatthesampledoesnotbecome

contaminatedduringthesampling

process.Thiscandistortanddisturbthe

data,makingitdifficulttodistinguishwhat

wasoriginally

in

the

oil

from

what

came

intotheoilduringthesamplingprocess.

WhyIsItImportantToPullA

RepresentativeSample?

1.

Toensurethereisasmuchinformation

permilliliterofoilaspossible.

2.

Tominimizecontamination.

Propersamplingproceduresbuildthefoundationofan

effectiveoil

analysis

program.

Without

good

sampling

procedures,timeandmoneyarewasted,andincorrect

conclusionsmightbereachedbasedonfaultydata.


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WHATEQUIPMENTTOINCLUDEINSAMPLEPROGRAM

Alltoooften,maintenanceprogramsfocus

onsamplingmoreequipmentratherthan

samplingattheoptimumfrequency.

Whenoptimizingsamplingfrequencies,

thebestwaytostartistodecidewhich

machinesshould

be

sampled.

Its

better

to

becommittedonthemostcriticalassets

thantoperformineffectiveoilanalysison

allofthem.

Whenyou

start

implementing

an

oil

analysisprogram,youneedtodecide

whichequipmentintheplanttosample.

Thiscanbeadauntingtaskbutitcannot

beoverlooked.Supervisorsand

managementneedtotakethetimeto

identifythetargetedequipment,write

detailedprocedures,establishroutes,and

samplingschedules.

Equipmentcriticaltoplantoperations

shouldbeidentifiedfirst.Thisequipment

oftendoesnothaveabackupunitto

replaceitwhenitisnotinservice.In

addition,majorrepairsandoverhaulof

criticalequipment

often

require

a

completeplantshutdown,substantial

manpowerandsubsequentlossof

productionactivities.

Criticalequipment

in

plants

typically

have

thesecommoncharacteristics:

Theyrequireveryhighcapital

investmentandareexpensiveto

maintainandrepair.

Theyareengineeredforlongservice

liveswhen

operated

within

design

specificationsandinapredictable

environment.

Manyarequitelargeandaremadeup

ofseveralindividualcomponents.

Downtimeisquiteexpensivesince

productionisusuallyhaltedwhen

unexpectedproblemsorasystem

failureisexperienced.

HowToSelectEquipmentForSampling

Establishcriticality

Whatwillhappenifthisequipmentfails?

Repaircost

Whatwillitcostifthisequipmentfails?

Maintenancehistory

Hasthisequipmentbeenpronetofailure

inthepast?

Safetyconcerns

Willasafetyhazardresultfrom

equipmentfailure?

Currentpractices

Arewespendingtoomuchon

maintainingthis

equipment?

Currentperformance

Arewegettingthemostoutofthis

equipment?


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WHATFREQUENCYSHOULDIPULLSAMPLES?

Manypeopleregarddrawingoilsamples

asanastimeallowsactivityandfailto

reapthebenefitsthistechnologyhasto

offer.Itshouldbetakenseriouslyandbe

performedwiththeutmostcareand

diligence.It

is

not

enough

to

simply

fill

a

bottlewithoilfromthesystem;youmust

performthistaskproperlytoaccurately

trendthedatayoureceivebackfromthelab.

Thereis

no

universal

formula

for

determiningoilsamplingfrequency,but

mostexpertsconsidermonthlysampling

tobeoptimumforcriticalmachinery.

However,whenmakingthisdecision,itis

importanttoconsidertheobjectivesof

theoilanalysisprogram.Iftheonly

objectiveistoperformconditionbasedoil

changes,thesamplingfrequencyshould

bedeterminedrelativetothelubricants

expectedservicelife,whichisdefinedby

theOEMrecommendedoilchange

frequencies.

Inmostsituations,thisisnottheonly

objective,oreventhemostimportant

one.The

real

value

of

oil

analysis

is

its

abilitytoserveasaproactivecondition

monitoringtool,allowingforthedetection

andquantificationofparticle

contamination,moisture,foreign

lubricantsor

fluids

and

assessing

overall

lubricantcondition.

Inadditiontothecriticalityoftheasset,

onemustconsiderhowthemachine

wouldbeeffectedbyanunacceptable

amountofcontaminationandthe

likelihoodofacontaminationorother

abnormalcondition.Ifoilanalysisisused

asapredictiveconditionmonitoringtool,

thebiggestconsiderationisthelikelytime

periodbetweendetectionandfailure.

Obviously,thesamplingfrequencymust

beshorterthanthisperiodtobe

successful.

IdealSampling

Frequency

EquipmentCriticality

ExtremelyCritical Weekly

Critical Monthly

NonCritical Quarterly

EquipmentHistory

Equipmentpronetofailureshouldbesampledmoreoften

EquipmentVulnerability

Equipmentwithariskofoil

contaminationshouldbesampledmore

often

Loadvariations,hightemperatures,

operationalfactorsneedtobe

considered

NewOil

Samplebulkoilshipmentsand

equipmentdirectlyafteroilchangeto

ensureproperlubeisinuse.


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LOCATINGIDEALSAMPLEPOINT

Routineoilanalysissometimesrequires

theuseofspecializedhardware

permanentlyinstalledinthemachineor

componentfromwhichanoilsamplecan

beextracted.Itisextremelyimportantto

installthe

sample

valve

in

an

ideal

location.

Thebestlocationforextractinganoil

samplefromasumporreservoirisas

closeto

the

return

line,

gear

set,

or

bearingaspossible.Youalsoneedtomake

surethereisenoughroomsurrounding

theterminationpointofthehardwareyou

havechosentouse. Maintaininga

distanceoftwoinchesfromanystaticor

dynamicsurfacewithinthecomponent

putsyouontherightpathtoaquality

sample.Hardwarethatextendstoofar

intothemachineriskscontactingmachine

surfacesandcausingdamage.

Hardwarethatterminatesonorcloseto

thesurfaceofthemachineorcomponent

riskscollectingcontaminantsthatcan

skewthedataandresultinunreliable

analysis.

PointstoRemember:

Sampleshouldbegoodrepresentation

oftheoilinthesystem

Samplinglocationandmethodmustbe

consistent

Neversampleonadeadleg

Takesamples

while

equipment

is

running

Yoursamplelocationshouldlenditself

toacleansample

Asamplinglocationshouldbeidentifiedtoallowfortroublefree,

repetitiveandrepresentativesamplingofthehealthoftheequipment

andthehealthofthelubricant.Thissamplingmethodshouldallowthe

equipmenttobetestedunderitstypicaloperatingconditionwhile

maintainingasafesamplingmethodforthetechnician.


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WHOSHOULDPULLTHESAMPLES

Establishingeffective,userfriendlyoil

samplingprocedureshelpstobuildanoil

analysisprogramthatcreatesvalue

throughbettermaintenancedecisions.

Oneaspectofareputable,selfsufficient

oilanalysis

program

that

is

often

overlookedistraining. Thepersontaking

thesampleisjustasimportantasthe

personinterpretingtheresults,but

insufficienttrainingoftenleadstothe

sampletaker

being

the

weakest

link

in

the

predictivemaintenancechain.

Trainedtechniciansthatunderstandhow

importantqualityoilsamplingprocedures

arewillbekeyinmaintainingaprogram.

Oilanalysisisascience,andthetestsare

onlyasaccurateasthesampletheyare

performedon.Improperoilsamplingcan

leadtoafalsepositive,whichresultsin

shuttingdownequipmentunnecessarily.

Evenworse,

it

can

lead

to

afalse

negative,

whichcanleadtoanunidentified

equipmentfailure.

Thereareseveralcompaniesthatoffer

excellenttraining

in

lubrication

fundamentalsandpracticesandmostwill

bewillingtocometoyoursiteifyouhave

enoughpeopletofillaclass.Donotforget

toincludesupervisorsandmanagers.They

needtobeonboardandbeawareofwhat

isrequiredandthebenefitsthatcanbe

achievedbyimplementinganoilanalysis

program.

Oilanalysis

is

an

ever

changing

technologyandtoreapitsbenefits,one

mustcontinuallyreceivequalitytraining.

Trainingoptionsmayinclude:

Classesand/orcertifications

Tradeshowsandconferencesare

anotherwaytohelppersonnelstayon

topofrecentadvancesintheirfield

Departmentbudgetshouldreflectthese

educationalopportunitiesfromyearto

year.


8/16


HOWWILLSAMPLESBECOLLECTED

Thewayasampleiscollected,the

accessoriesusedandproceduresfollowed

dictatehowinformativetheoilsamplewill

beandhowbeneficialtheanalysiswillbe.

Thatiswhyitisofgreatimportancethat

thesample

be

taken

correctly.

If

the

oil

sampletakenisnotrepresentativeofthe

oilinthemachinethentheresultsofthe

oilsamplewillnotaccuratelyreflectthe

conditionofthatcomponent.Theresult

willbe

an

incorrect

diagnosis

based

on

incorrectanalysisbecauseofapoorly

takensample.

Whichsamplingmethodisbest?

Thatreallydependsonthesystembeing

sampled.Forgearboxesandotherbath

lubricatedsystems,aminimesstype

samplingvalvewithapitottubeisthe

usuallythebestoption.Thisapparatus

usesafixedtubewhichcanbecutto

lengthandpositionedinadesirable

locationinthesump.Thisissimilartothe

droptubemethodbutiteliminatesthe

mostcommonproblemsassociatedwith

droptubesamplingwhichareinconsistent

placementof

the

sampling

tubing,

the

excessivesamplingpathwayvolume,and

overalldifficultyortimerequirementto

collectthesample.Theuseofaminimess

andpitottubeminimizesthesampling

pathwayand

ensures

aconsistent

extractionpoint.

Droptubesamplingreferstotheuseofa

flexibletubewhichisinsertedintothe

sumpbyhand.Thismethodmayproduce

validresults,buttodosoyoumustbe

verycarefulandyoumustbeawareofthe

potentialproblems.Whiletheminimessis

certainlythepreferredmethod,droptube

samplingisanacceptablealternative.

Mostother

sampling

methods,

such

as

drainportsampling,willnotyielduseful

resultsandshouldbeeliminatedfrom

yoursamplingprogram.

Forhydraulic

systems

the

primary

sample

pointshouldbeonapressurizedportion

ofthesystemupstreamofsystemfilters.

Allpressurizedsystemsoffereasy,

consistentsamplingiftheyareproperly

fittedwithsamplinghardware.Thesame

Iftheoilsampletakenisnotrepresentativeoftheoilinthe

machinethentheresultsoftheoilsamplewillnot

accuratelyreflecttheconditionofthatcomponent.


9/16


typeofminimesssamplingportcanbe

utilizedalthoughnopitotisrequired,and

ifthesamplebottlecapisventedthereis

noneedforavacuumpump.

Toaddresssafetyconcerns,itisdesirable

tousealowpressureportionofthe

systemsuch

as

the

pump

case

drain

or

a

bypasscircuit.Theselocationsoffereasy

sampling,safepressures,andconsistent

dataaboutthepumpsandthefluid

cleanliness.

Forothercirculatingsystemsitis

reasonabletosamplefromthepressurized

portionofthesystem(afterthepumpand

beforethefilter),butitmaybebetterto

samplefromreturnlines.Bysampling

fromthereturnline,youcangethighly

concentratedweardebrisinformation

makingthe

oil

analysis

avery

sensitive

predictiveconditionmonitoringtool.

Whatistheproperprocedureforeach

method?

Fordroptubesamplingtherearequitea

fewcommonmistakes,butawellthought

outanddocumentedprocedurewill

ensurethebestresults.Alwaysuseanew

pieceofsampletubing.Inanysampling

procedure,alwaysbeginbyflushingthe

samplingpathwaywithapproximately3

timesthevolumeofthepathway.

Techniciansoftenchoosetousea

dedicatedwaste

oil

bottle

for

flushing

that

islargerthanthesamplecollection

containerssotheycantypicallycomplete

asamplingroutewithouthavingtoempty

thewastebottle.Theproperlengthof

tubingshouldbepredeterminedsothat

youcaneffectivelyinsertthetubeendin

themiddleofthereservoirwithout

touchinganything.Ingeneral,thetube

endshouldbeatleasttwoinchesfromthe

bottomofthesump,twoinchesfromthe

Samplesshouldbetakenfromturbulentorlivezones

withintheoilsystem.Pullingasamplefromthedrainvalveis

notanaccuraterepresentationoftheconditionofthe

machine.Wear

particles,

contaminants

and

water

settle

to

thebottomofthesump,thusmakingthissamplefullof

historicaldataanddifficulttotrendasyoucontinueto

samplefromthislocation.


10/16


sides,twoinchesbelowtheoillevelandat

leasttwoinchesfromanymovingparts.

Thiscanbedifficulttoaccomplishwithout

threehands,butifyouuseaone

handedpumpitiseasier.

Forsamplingfrompressurizedsystems,

theextraction

is

simpler

because

a

vacuumpumpisnotrequired,andif

tubingisnecessary,onlyashortlength

needbeused.Ifthesampleistobe

obtainedfromahighpressurelocationin

the

system,

additional

steps

such

as

the

useofapressureregulatormaybe

requiredforsafety.

Aswiththedroptubemethod,beginby

flushingthesamplevalveandtubingwith

3timesthepathwayvolumetoawasteoil

containerbeforecollectingthesampleto

beanalyzed.Anotherhardware

requirementforpressurizedsamplingisa

ventedsamplebottlecap.Ifsuchacapis

notavailable,

you

can

attach

the

sample

bottletoastandardvacuumpumpto

allowthebottletovent.

Whilethereareseveralacceptable

sampling

methods

for

each

machine,

there

isusuallyonebestway.Thebestsampling

methodswilltypicallyrequiresomework

upfrontinthatyouwillusuallyhaveto

installsamplinghardware,buttheend

resultwillbewellworthit.Usingfixed

hardwareinstalledinthecorrectlocation,

willprovideconsistent,validdatawith

whichyoucanmakegooddecisionsabout

machineandlubricantcondition.Withthe

samplelocationselectedandtheproper

hardwareinstalled,

all

that

is

left

is

to

documentadetailed,stepwiseprocedure

thatwillensurethesamplewillbetaken

correctlynomatterwhotakesit.

Thebestsamplingmethodswilltypicallyrequiresome

workupfrontinthatyouwillusuallyhavetoinstall

samplinghardware,buttheendresultwillbewellworthit.


11/16


IDEALSAMPLEPOINTSBYEQUIPMENT

TOP5SAMPLE

POINTS

FOR

GEARBOXES

Gearboxes

Breather/Fill Cap

DipstickTube

InspectionCover

Drain

Sight

Glass

2

4

5

3

Sample

Valve

1


12/16



TOP3SAMPLE

POINTS

FOR

BEARINGS

Bearings

Breather/Fill Cap

Drain

Sight

Glass

2

3

1SampleValve


13/16



Top4SamplePointsforReservoirs

Reservoirs

Breather

Drain SightGlass

SampleValve

Hatch

12 3

4


14/16


IDEALSAMPLEPOINTSBYEQUIPMENTUSINGASAMPLETUBE

How To Use Tubing Sampling

Sample

Tubing

Clean

Rod

MeasuredDepth

CleanWeight


15/16


HowToSample

SamplePumpMethod

Cutnewsampletubetodesiredlength

o Sampletubelengthshouldbethesameeachtime

sampled,considerrecordinglengthforeachcomponent

Insertsampletubeintosilverdiskontopofpumpsothatthe

tubeprotrudesfrombottomofpumpapproximatelyinch

Tightensilverdisktosecuretubing

Removesamplebottlecapandsecurethebottletothesample

pump

Insertsampletubeintodesiredsamplelocationsothattipof

tubingisinthemiddlephaseoftheoil

Pullavacuumonthepumpbypullingthepumphandle1to3

times

Allow

the

sample

bottle

to

fill

(you

will

not

need

to

continue

to

pullhandletomaintainsampleflow)

Holdpumpuprightwhiletakingsample

Whenthesamplebottleis full,loosenthesamplebottleto

releasethevacuumandstopthesampleflow

Removethesamplebottleandrecapthesampleimmediately

Removetheusedsampletubingfromthepumpanddiscardand

donotreuse

Wipethe

sample

pump

with

aclean

cloth

to

remove

any

oil

DrainValve/BallValveMethod

Openvalveandallowoiltoflowuntilanywaterorsedimentis

flushedfromthevalveandpureoilbeginstoflow

Removecapfromsamplebottleandfillbottletocapacity

Replacecapimmediately

Closevalveandreplacecaporplug

WhenToSample

Whileequipmentisatfulloperatingtemperatures

Duringoperationifpossible

Directlyaftershutdown

WhereToSample

Sampleshouldbegoodrepresentation

oftheoilinthesystem

Samplinglocationandmethodmustbeconsistent

Neversampleonadeadleg

Takesampleswhileequipmentisrunning

Yoursamplelocationshouldlenditself

toaclean

sample

ShippingSamplestotheLab

Wipesamplebottlestoremoveresidualoil

Fillindateandanyoilchangeinformationonpreprinted

samplelabels

Affixlabel

to

bottle

and

place

in

sample

mailer

or

sturdy

box

Shiptolabusingpreferredcarrier

SAMPLING PROCEDURES

CH E C K L I S T


16/16


ABOUTTESTOIL

TESTOILisafullserviceoiltestinglaboratoryownedbyInsight

Services. Since1988thelaboratoryhasbeenprovidingfast

andreliableoilanalysisresultsacrossallindustriesthroughout

theAmericas.

Thefirmscomprehensiverangeofoilanalysisservicesassists

reliabilityengineerswithconditionmonitoringand

identificationof

machine

wear.

TESTOILemploysasophisticateddiagnostictechnologythat

assiststheirMachineConditionAnalystsinmakingequipment

andlubricationconditionassessments.

Fix The Weak Link Today!

SamplingBestPractices

Alertproductionthatyouareinthearea

Wearrubbergloves&otherpropersafetyattire

Keepallsamplepointscappeduntilreadytouse

Flushasamplepointbeforesampling

Cleanasamplepointbeforesampling

Nevercloseavalveinthemiddleofasample

Alwaysusecleantubingforeachsample

Useapropersamplebottle

Capsamplebottleimmediately

Makesurebottlecapsaretight

Properlylabelasamplebottle

Shipsamplesthesamedaytheyarecollected

fix the weak link- sampling

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