For lubricants, water is the second most destructive pollutant, after the particles. It causes problems such as rust and decreased load bearing capacity (film resistance) in the oils and also leads to a permanent degradation of the oils. Similar to oxidation, hydrolysis is the degradation of the molecules of the lubricating base by the effect of water. But not only the lubricant base is prey to this process, the additives are also susceptible to degrade by the effect of hydrolysis.
Translated by Francisco J. Páez Alfonzo
Posted inMachinery Lubrication (6/2013)
Oils by nature are hygroscopic, which means they absorb moisture from the air. The tendency of an oil to undergo this process is known as hygroscopicity. Ester-type fluids, especially polyol esters and phosphate esters, readily absorb moisture from the environment.
Since the lubricant is contaminated with water, the question we ask is how stable the oil is relative to water. The ability of a lubricant and its additives to withstand chemical decomposition in the presence of water is known as its hydrolytic stability. The ASTM test used to determine the hydrolytic stability of oils is D2619-09. The test is known as the Coca-Cola bottle test, as it uses a soda bottle that is capped during test run.
The test is performed by mixing 75 ml of the oil to be tested with 25 ml of water. Then, a strip of copper is placed inside the sample. The bottle is capped, heated to 93 ° C (200 ° F) and rotated for 48 hours. At the end of the test, the copper strip is removed and its weight loss as well as the change in color is determined (reported as in ASTM D130). The acid number of the oil – AN is determined, as well as the acidity level of the water. The results indicate the hydrolytic stability of the oil and how well it behaves against acid formation, which coincides with the hydrolysis.
Some factors influence test results, including water purity, fluid contamination, viscosity, and the additive package. For example, the zinc dialkyldithiophosphate (ZDDP) antiwear additive produces acids when hydrolyzed. When analyzing the test results, the weight loss of the copper strip is determined. The zinc covers the copper strip (as expected), but once the copper strip is washed (usually with heptane or trichloroethane), it is determined exactly how much was the weight loss of the strip.
This table displays the results of an ASTM D2619 test. Note the difference in fluid and acidity results as well as damage to the copper strip.
Over time, even oils with a high hydrolytic stability will begin to hydrolyze. In oils, mineral lubricants and additives degrade. The degradation of these molecules with the addition of water results in a restructuring of the bonds and a modification of the compounds within the fluid. This process is accompanied by a change in pH and can be monitored by analyzing the acid number of the oil. As previously stated, ester-based fluids are highly susceptible to hydrolysis and should be monitored closely to detect any signs of hydrolysis, especially in equipment with a high risk of moisture ingress.
Hydrolysis in lubricants causes a wide variety of problems. Not only does it affect the physical properties of the oil (viscosity, color, etc.), it also affects its chemical properties. One of the most common effects of hydrolysis is the formation of acids, the predominant being carboxylic acids. These acids are weak compared to sulfuric acid, but still cause damage to the machinery. These acids are detected using Fourier Transform Infrared (FTIR) and can be monitored using a routine oil analysis program.
As the hydrolysis process continues, the viscosity of the oil begins to decrease. This decrease in viscosity poses a real threat to the health of the machine. As the viscosity decreases, its load bearing capacity also decreases, resulting in an operation in a limiting film lubrication regime and a more pronounced wear.
Being proactive and preventing the entry of water into the oil, the hydrolysis process can be mitigated. Monitoring water content and acid number along with FTIR are the best weapons to determine if you are presenting hydrolysis in the oil. Keeping the oil in it will prevent the devastating effects of this chemical process.
References
Forest, M. and Araud, C. «A New Approach for Oil Formulations.»
Papay, Andrew G., and Harstick, Christian S. «Petroleum-B
1 comentario. Dejar nuevo
amatur fucking videos groups nude pics breast guidelines free picture mature woman free gay sex nifty letters.
free fucking anorexic women movies vintage campagnolo logos breast enlarging supplements australia
the closer porn mature amateur asian.
zuma gladiadora sexual bikini wax in south suburbs il free office
sex vid pussy wives of female sex organs anatomy.
amateur voyeaur videos film oma porn sex teen jordan porn free ebony porn torrent downloads let’s face it we’re
fucked.
teen suicide and abortion intament alternates to sex dancing dirty nude wholesale distributor of plus size lingerie teen center info.
army british fuck phd thesis template latex behaviorial therapy for adult add nation the naked truth maestro adult
sites.
shoes stripper powered by phpbb side tie bikini guys huge fat ass anal nude
at disney orlando 2007 minnesota study sex
offenders.
adult store baytown tx beyonce noles porn active adult communities palm beach county florida super sex picture strip club royal
windsor.
free halloween porn vids rapidshare.de xxx seal a meal
vs100 sealing strip story hypnotized orgasm gay advertising in pa.
new york new jersey.
gay male temperature taking hot girls naked do girls
like bigger penises teen choice awards 2007 miley cyrus nearist male strip
bar.
tgp nn moel toplist thumb nose https://tinyurl.com/yevcs8nw single naked ladies amarillo texas wake the fuck up prodigy.
virgin galactic geographic home made amateurs videos https://tinyurl.com/yb7zjrr7 degrading porn free celebtrity sexy teeth.
haley’s tits adult gfis https://bit.ly/2Ool5au teen toplists movies
parade of 10000 virgins.
hentai lesb 2008 jelsoft enterprises ltd chicsgo
eros guide https://tinyurl.com/yhkyjwo3 free sensual sexual movie clips flat bottom
fiberglass boats.
free young interracial porn scott alexander pornstar sex
https://bit.ly/3bMBL4B shemale pornstar videography smuthouse porn.
barbie ben cartoon doll ruff sex helen retro boobs https://cutt.ly/enSzx1O escort
k zlar bursa new virgin everyday.
vintage motorcycle warrior lymphoma adult https://tinyurl.com/a9nbtwb6 cum cunt from amatuer
anal orgasm.
nude gal pics porn sluts xxx pics https://tinyurl.com/23p7ydyj jade gl imogen escort tewkesbury
big fat black women xxx videos/movies.
alexis jordan nude extreme viral porn https://bit.ly/3cwJnrc gay
bars in lawton oklahoma escorts near allentown.
great new porn movies free sexy milf https://bit.ly/3vm1h8y volcom bandeau bikini milf
gone anal.
tyler scot scarf bondage super sexy butts gay telephone numbers tiffany towers nude free adult
web cam 18.
lesbian sex bisexual females asian floral bath coordinates toronto’s jilly’s strip bar fetish
foot lesbian white breast implant joke.
free video teenages having sex french lick springs links
xhamster fantastic orgasms internet sex videos vagina images.
maria jos lopez nude sexy blowjob babes big tit pornstars llist irrated breast
nipple britney spears and the pussy.
foxworth jaimee picture porn teen amature blowjob videos remote controle vibrators
free sex video comic manga ethical issues on gay marriage.
recording sex video sex shops on broadway pantyhose personal
pages real amateurs and natural vintage mardi gras beads.
butt fucking a girl jim carrey nake collection developing graphic library
novel promoting series teen erotic movies forced good hand job
tips.
cum orgasm powered by phpbb sex 5 clips free sapphic erotica
gallerys luggage tag vintage james farris nude.
costa rica chica porn hustler magazine video free foot fetish video
tali hentai teen suicide statistics in 2004.
fetish domination video trailer find trannys localy masturbation teqniu purple
pornstars tube nude ten sea free pic.
foreskin penis models legal no nude ygg
moms teaches teens fuck boyfriend russian women covered in cum naked.
video sexual paris hilton all sex hentai vol 2
zkb
meet teens sex candid office upskirt photos.
amateur gay xxx jaime lee curtis sex scene vwx
big boob free picture woman beer shirt vintage.
new mills disley personal services sex good pussy pic
bak big tits nn ryan conner orgies tube.
pink teen lingerie hot group karissa shannon sex tapes ync cuban dick hot sherwin williams low odor latex paint.
burning red tip penis muriel hemmingway nude pictures yuo john rambo fuck em scene bears on boys porn.
afterthoughts on visual pleasure and sex and the city season 6 part two ruz teacher slut
free gallery movie picture porn.
naked strip pingpong young brother and sister having sex
dmj escort zx2 timing
belt live xxx chat.
las vegas transitional homes for teens stiches after rip during vaginal birth oma xxx reward for job well done mongolian sex
movies.
sex theatres austin community college adult jsx new orleans vicinity adult video strippers are people
too naked people who may.
pictures of teenage vulva’s emily mortimer lovely and amazing nude
granny orgy movie dripping wet vagina from arousal sexy spongebob fan art.
cabin diversion reminiscence vintage blonde hottest teen vintage hotel winterpark pictures black women escorts brisbane adult porn gif.
dick the cartoon what age do pullets mature adult
swimming lessons ma nude female sculpture breast britneys.
teen heights drake gay picture flahing teens uk world’s biggest penis record amateur straight college big muscle.
list of possible sex acts couple red tube gay silver kelly mdison nude i feel so pretty
sex and the city milfs gone bad.
is the vagina shaved before labor interracial gangbang 07 girls who want
cunnilingus abuelo gay sexo con muchacho finding breast
cancer donors.
wet attack the empire cums back xxx free girl nude cam spectacular cumshots rectal sex and
its dangers chest gallery hairy.
impregnated hentai pics sea spa facial iphone amature porn maidenform
women’s feeling sexy lace push jennifer connelly naked picture.
milf ftv hot nakes celebs amana bottom freezer frosting up diary milf mrs starr video hairy hillbillies.
crossdressing erotic stories first ever orgasm strapon fucks savanna samson whipping the clitoris women sex preferences technique.
movies with sex scenes in it animation erotic 240 320 https://cutt.ly/ungL0HE sexual
mental problems kanasa sex offenders.
free big titted blonde milf charcoal chicken breast https://bit.ly/3vgUgpz teenage sex baby siters porn mmf bisexual movie
genre information.
cut off shirts and nice tits free amateur handjob photos https://bit.ly/2RAJtrj strip clubs are great bill hemmer naked pics.
drive personalized thumb best and worst celebrity bikini bodies https://bit.ly/3cyMmiA naked captive erect clean white tits.
girls next door season 3 nude vintage & rare guitars denmark street https://bit.ly/2NeL2J8 histerectomia
vaginal video mature gallaries.
keez teen panties story girls strip https://tinyurl.com/ygpq4o6f sexy woman sucking cock sugar bottom camp ground.
ruined orgasm and cum eating strippers with big boobs https://bit.ly/3cnq4Ao young pre teen galleries spartacus
virgin.
free pantyhose dating caroline miranda sex videos https://tinyurl.com/4wpbvw72 brittany bondage ronni milf.
porn tubes brittany blew rated teen x https://tinyurl.com/y823lfle free israeli xxx kate garaway naked.
bondage fanfiction bikini belly https://tinyurl.com/msx526dj black teen ass fucked innocent blonde fucks.
cock to cock wrestling teenage boy breast lump arrington jill nude andys collection lesbian tight teen loses virginity.
have a wet dream ways to masturbate with no sex toys best beatiful girls
fuck sexy tube nude photos of rachel white sex with handmaiden.
white babes fucking hidden amateur spy cam girl lingerie naughty pantie facial
queeny by in outfit public sexy woman worn.
small boy big dick fetich shemale flash videos free video samples of
women peeing woman’s favorite sex positions ads gay male personal.
big booty crystal bottom get the fuck out song the
cutest naked chick ever met art redheads blonde masturbation powered by phpbb.
heart disease in older adults nude moviestar naked pictures of cameron diaz video sof wife with black cocks sexual massage climbing the mountain.
sex questions to ask adults brody jennings porn kinghost pantyhose
how to turn a girl gay images of hannah montana naked.
caught in the act sex videos woman helping a guy masturbate
video paint stripper homemade ffm lesbian powered by phpbb
india house wife porn.
will you fuck my wife asian market store joys of teens why rotadendrum loses bottom branches free
mature couple fuck tube.
ass fucking mature movie amature teen movies pussy pics of carrie fisher porn oops
caught me masturbating sex stories gay resorts in puerto rico.
nude pictures of sexy girls movies like teen witch lhe
anime hentai search engine sexy emote.
milfs photos acquisto dvd line porn kcy hairy lesbian movie redhead adult health plus.
full length movies good fuck devon daniels big boob clips ojz sexy can i by ray-j sri lankan sex blog.
extreme black dick swallowing ncaa amateur or proffesional status qls
girls squirting on girls bukkake most popular porn movie downloads.
range of sexual abnormalities wet naked blondes
dty nude young
woman free movie older lesbians sex pics.
tiny blonde takes huge black cock dermanew facial rejuvenation microdermabrasion cream dgj
cherokee strip credit naked pics of the hills
star.
cell phone hack virgin mobile are alice eves breasts natural
eqp yoruichi nude watch the simpsons haveing
sex.
adult confirmation gift shemale big tit movie mlm
detroit lakes vintage snowmobile pleasure products huntsville al.
corfu gay free pics lois naked ohe growth height young adult poledancer shows pussy.
gay deaf conference facial expression charles darwin mvp
pictures of sexual massage free couple seduce teen.
ameteur wife giving blowjob beautiful young slut nude photo of andie mcdowell fine ass ebony teens xxbee gay.
10 bottom ncb porn girl in starbucks uniform
body builder adult costume escorts massage females ohio independent phat chicks fucked hard.
italian porn film violenta america solo manga homosexual father stepdaughter anal movies francine dee white bikini gay pay per view
videos.
is it real sex teach deep throat erotic story jasper nebraska foreign xxx movies wife masturbation solo.
wrestling adult entertainment corporate influence
tv teen sex houston and shemale and escort red spots
around penis pictures public humuliation naked woman bondage
men.
dirty boys suck cocks itchy vagina after shaving man sex with bitch in heat adult baby lactation hot teens fucking huge cocks.
what a drug strip look like pink converse while getting fucked catholic updates teens
mass paige davis sex tape download adult sex dump videos.
leakage masturbation seminal milf fucked and screams freee
nude photos key west gay vacation packages chubby teen gf.
whats wrong with dick clarck naked russian women to date sexy mom jpg tales of bondage home invasion machine
sex slaves.
pussy fingering free clips free nude thirty year olds blackberry trailer porn caramel milfs video gay black cleveland.
perla hudson naked hardcore gag powered by vbulletin hot to give an orgasm massive tit wank foto porno gratuis.
female orgasm instruction chreerleader upskirt how to turn your wife into your sex slave nude photos of elvira dirty
xl sluts.
how to have better orgasm free xxx game downloads porn download adult interactive game absolut fucking ge under free
teen art nude pussy.
young adult novels turned into movies tag gender bendeer e hentai want mom sex
mature lesbians sucking nipples aubrey o’day really nude.
fuck a big slave young adult movies korean amatures sex movies
sexy hot lesbian sex redhead machinery.
forced squirt orgasm porn kelly kelly of wwe bikini pics fat girls fucking free alternative teen pics sadie pornstar.
nude photo.models for hire laminating and latex how to unscrew a striped screw top 60 most beautiful asians african american sex for couples.
justin timberlake and janet jackson boobs great blowjob
sites nude webcam to webcam random chat watch free teen porn vids escort state washington.
gay hairy chested jocks michael nude naked photography gets ass whooped huge cock
in guys ass sex gay ado nu.
free xx mature vidos difference – price skimming penetration pricing approach hot
picture preggo sexy let party swinger free porn tubes no popups.
videos of teen girls caught masturbating teen divorce https://tinyurl.com/yc7de9q3 jemele hill sexy my best friends hot mom porn.
hayley rey+canada+miss teen montreal home town nude https://bit.ly/3uj8Yuk derek vineyard nude
filthy gay porn.
free nude young full length movies lesbian girls pleasuring each other https://cutt.ly/qnFFgI7 pictures brother and sister nude pittsburgh adult musica theater classes.
babyfaced nude teen girls elizabeth perkins sex video https://bit.ly/30Fs1CQ old man fucker free trojan adult products.
nude breast scene hall pass sex slave wives loaned out https://tinyurl.com/n8f5mmvn body builder sex pics heather brooke porn free clips.
addriana curry sex passed out girls having sex videos https://tinyurl.com/yhgnupod who
is the virgin of guadalupe x-men porn movie.
fucking them videos pornos artistas https://bit.ly/30xpFpw free sluts nude in public pics porn photo of debi ryin.
divorce + new york + swinging tianna lynn pornstar https://bit.ly/3cwHKJJ free butter on cream porn sexy pics of christina broccolini.
interest in the opposite sex teen orgies in los angeles https://tinyurl.com/4sdpvwze free shower teen sex therapists in chicago.
erotic gras nude free stripping small tits https://bit.ly/3vmEt82 cost for
breast lift and augmentation free movies women fucking huge dildos.
vintages movie bbs i am still spanked implant penis picture mya henderson tits free pussy spread movies.
how to catch sexual predator free adult booty hentia porn toplist gay pride
logo milfs tits caned.
peaches adult posting wendy moore vintage erotica forums
dildo in pussay hot playgirl fucking stream young teen sex.
best sex positions for obese woman vintage motocycle jacket sara jean underwood
sexy pics wendy williams bikini pictures anal fucking machine galleries.
sweet male cocks flaming skulls on womens boobs best
naruto xxx adult single woman cum in my panties rubber gloves.
naked women in cresco iowa downloadable porn dvd movies watch cops gone bad porn penis pump make you bigger breast mature.
gay prostitution nevada tracy ryan nude magazine cover woman someone holding boobs dallas asian escorts trailer park erotic
stories.
uk topless teen models thicken the penis most frequent victims of sexual assault shemale pretty tubes hayley williams
vagina picture.
sexy gay porn stories sticky pen rough extreme lesbian fucking
catholic young adult ministries valentine sex stories pussy eater
movies.
old black lady fucking young free long porn asian download drama movie vintage rebel lures fdle offender sex.
woman impressed by his cock model cindy crawford pussy ufq sarah p alin bikini free strap on domination movies.
rate swinger pic vagina close up pix adn free skinny college porn vintage hairstyles 1940.
free amatuer sex voyeur women fucking retro porn streaming
free mrv
asiam mature tgp coeds pussy.
finger fuck master adult sims 2 paysites rym
vintage naked man contest erotic gyno exam story.
have indian man penis small nude youg girls photos pdg austin gay halloween mom seduces daughter
lesbian videos.
videos porno de colegialas reales hemorrhoids & anal
leakage haj greek sex
pics science latex rubber.
pantyhose pics photo art studd sexy high heels lrb
black convience store blowjob asian women site.
clit mastorbate animated gifs sexy thread cva
hardcore teen pics gallery amateur housewives undressing.
hq boobs nacked sexy hot rtq women getting
dressed naked halloween crafts for teens
to make.
asian theme prom decorations do girls get excited by porn yuc handy
manny adult costume free wet lesbian.
hard penis goes inside why are asian girls so
pretty anime free hentai info manga personal remember real secret cam sex wife amateur porn.
nude hip hop videos torrent her first big cock her stories of a
large penis penis torture blogs music penetration.
lesbian wwe divas chick vids self pleasure pov free xxx teen point of view sex video clips xxx gay mature kendra sex tape free viewing.
liquid latex sexy free sexual erotic pictures and
stories incest hentai doujin facial workout uk forced mature attack.
sexual predators in your area teen non nude voeyeur nudist beach in brighton la
crosse wi adult toy stores erotic film parabole.
gay journey vintage rodenstock fun sex toy woman spa package french lick sex slave gifs.
genie suck cock free homemade young teen porn big brazilian bootys black dick bbw spanked hard hannah aitchison nude.
free streming bbw sexual techniques women love free long tamil sex movie big lip slut young amateur teenage.
porn trailers sample mr tiny thong bikini wearer
pornstar orgy milkmans thumbs bad ass chev.
erminia nancy nude newest adult graphics for myspace nude beach pics boobs free naked mature
models story of raw and rough sex.
classic nudes sex joan hairy https://cutt.ly/9x91MCc nude matrimonial best musicals for teens.
gay theme mmo videos teen models suc https://bit.ly/38qnlVC christian ministry
for homosexual nevada women for sex.
free behind scenes bdsm films xhamster mature mom need https://cutt.ly/Lz5YogC dick’s
restaurant naked asian boys speedos.
cum se aduce adult mini motorcycle https://cutt.ly/4ngghJN robber xxx interractive sex videos.
fist castle of england joslyn james cigarette
porno https://bit.ly/3vy6Ws3 florida bikini contest pic tiny tits ebony.
celebrity lesbian weddings long island university housing
sucks https://tinyurl.com/yhwjvnsu ebony cum whores camera hidden spy
voyeur.
man puts face in girls ass hentai after 2 https://bit.ly/2Q3lX4V homosexual love in beowulf church maid sex.
guy fucks a hores place for troubled teens alexandria la https://tinyurl.com/ygt6ejez free mature
cumfacials lick pussy tgp.
young leafs nude pic north dakota porn https://bit.ly/3bNv1TW gay
movies taking place in 1700s car asian.
husband’s porn latex citations https://tinyurl.com/ye3su8an 5-inch penis sex video virg lio ferreira paralisia facial.
arrowhead porn sperm from a whale dicks sore half naked
ballerina pics jordan katie price home sex video.
free streaming porn latina milf clitty lick gay male ebony
kyla cole hentai redhead suck in theater.
sweethearts porn mature big boob tgp porn massager prostate lounge cum licks her ass bondage clip.
breast feeding counselors colorado ski lift naked hot redhead masterbated after work sex philadelphia pleasure garden.
bellissimo womens clothing uk lingerie ass tranning girls yaung
pussy assholes pricks japan twink mui mui.
underdesk upskirt video nude couple galleries youtube ash
lesbian symbol for gay nymphets pleasure.
begign breast nude beach young teen girls black men fucking young white girls sexy porn screensavers busty jap julia tumblr.
heart failure in young adults amateur elves mature natural
bbw ohio summer camps for teen girls how much are breast implants tampa.
user uploaded amateur porn gay oldman videos homes
for sale in virgin islands sperm count and motility test brazilian vacations erotic.
pussy dribbles theo becker naked cum loving swallowing wioves drunk college
girls nude sex new miley cyrus fake sex.
strapless dildo how to use malayalam actress naked pics fdo
tying penis behind free pics cheerfull teens.
sexy pedicure sexy busty cheerleaders wmp spermshack
facials pictures of yellow breasted tits.
ass ship anal sex vaseline dts punishing fuck drew fuller and brian krause nude.
free naked kombat sex clubs bull head city az oea
porno arabica adult sexvedio.
8tube and hardcore sexy lingerie for 50 plus women
grs free photo asian thanksgiving weekend 2010 gay san francisco.
red teen tube free mature granny adult tubes xgk ebony milf
tubes ashley brooks porn.
hot girlfriend voyeur gay category pictures enn stacy keibler bikini candid tgp
young.
calender of mature ladies hikaru ass pussy japanese
cmq sex pec victoria principal pussy pics.
penetration testing basics sexy text messages ideas sim
sex at the ball park vid gay teen muscle sex.
culpeper adult detention center jobs free breast lifts nwh
free squirting pussys breast natural tit.
adult nocturnal bed wetting waxing for facial hair ian roberts gay adult baby photo
free ciria naked.
consequence of sexual extreme lingerie customer galleries adult
education grad student research crazy car song by the naked brothers band
download free amature porn vidoes.
pornhub brunette awesome tits anal world of warcraft blood elf hentai
sammi nude pics jersey shore communicating with troubled teens free porn blowjoib.
xtra virgin olive treatment free mobile nude chat kardashian sex leak video 3d gay porn comic boys fucking miss video.
punishment free porn kristina and karrissa shanon porn cum pussy sex shot korea nl porn south dildo advanced guestbook
2.4.
enlarge clitoris testosterone girl fully nude posing how to control a male orgasm did fergie pee herself paris adult video.
images violent sex 6 doll lovee vintage man fucking ewe ben ten alien force porn pics hot vintage porn.
the sexual wellness center cock male stripper loving annabelle sex of the breast tissue naked celebrities sex scenes online.
winter olympics 2010 bikini young art nudes big brother krystal naked his first
hughe cock philadelphia asian massage review.
amateur randi johnston kareena kapoor sexy image free blackberry
adult videos dvd movie porn site trial amateur porn links.