Txoj cai ntawm kev kaw lub valve

Muaj ntau hom li qub, tab sis lawv lub luag haujlwm tseem ceeb yog tib yam, uas yog txuas lossis txiav cov dej ntws ntawm cov xov xwm. Yog li ntawd, qhov teeb meem kev sib khi ntawm cov li qub dhau los ua qhov tseem ceeb heev.

Yuav kom ntseeg tau tias lub valve tuaj yeem txiav cov dej ntws nruab nrab zoo thiab tiv thaiv kev xau, nws yog qhov tsim nyog los xyuas kom meej tias lub foob ntawm lub valve zoo. Muaj ntau yam ua rau lub valve xau, suav nrog kev tsim qauv tsis tsim nyog, qhov chaw sib cuag sealing tsis zoo, cov khoom sib txuas xoob, qhov sib haum xoob ntawm lub cev valve thiab lub hau valve, thiab lwm yam. Tag nrho cov teeb meem no yuav ua rau lub valve sealing tsis raug. Zoo, yog li tsim teeb meem xau. Yog li ntawd,kev siv tshuab kaw lub valveyog ib qho thev naus laus zis tseem ceeb ntsig txog kev ua haujlwm ntawm lub valve thiab qhov zoo, thiab xav tau kev tshawb fawb tsis tu ncua thiab tob.

Txij li thaum tsim cov li qub, lawv cov txheej txheem sealing kuj tau muaj kev loj hlob zoo heev. Txog tam sim no, cov txheej txheem sealing valve feem ntau pom tseeb hauv ob qho tseem ceeb, uas yog kev sib khi zoo li qub thiab kev sib khi dynamic.

Feem ntau, lub foob pob hluav taws xob hu ua static seal yog hais txog lub foob pob hluav taws xob uas nyob nruab nrab ntawm ob qho chaw uas tsis hloov pauv. Txoj kev sib khi ntawm lub foob pob hluav taws xob feem ntau yog siv cov gaskets.

Qhov hu ua dynamic seal feem ntau yog hais txogkev kaw ntawm lub valve qia, uas tiv thaiv cov khoom nruab nrab hauv lub valve kom tsis txhob xau nrog kev txav ntawm lub valve stem. Txoj kev sib khi tseem ceeb ntawm kev sib khi dynamic yog siv lub thawv ntim khoom.

1. Lub foob zoo li qub

Kev kaw ruaj khov yog hais txog kev tsim cov foob ntawm ob ntu ruaj khov, thiab txoj kev kaw feem ntau siv cov gaskets. Muaj ntau hom washers. Cov washers feem ntau siv suav nrog cov washers tiaj tus, cov washers O-puab, cov washers qhwv, cov washers zoo li tshwj xeeb, cov washers nthwv dej thiab cov washers qhov txhab. Txhua hom tuaj yeem faib ntxiv raws li cov ntaub ntawv sib txawv siv.
①Lub tshuab ntxhua khaub ncaws tiaj tusCov ntaub thaiv tiaj tiaj yog cov ntaub thaiv tiaj tiaj uas muab tso tiaj tiaj ntawm ob ntu ruaj khov. Feem ntau, raws li cov ntaub ntawv siv, lawv tuaj yeem muab faib ua cov ntaub thaiv tiaj tiaj yas, cov ntaub thaiv tiaj tiaj roj hmab, cov ntaub thaiv tiaj tiaj hlau thiab cov ntaub thaiv tiaj tiaj sib xyaw. Txhua yam khoom siv muaj nws tus kheej siv. ntau yam.
②O-ring. O-ring yog hais txog lub gasket uas muaj O-puab cross-section. Vim tias nws cross-section yog O-puab, nws muaj qee yam kev nruj, yog li qhov sealing zoo dua li ntawm lub gasket tiaj tus.
③ suav nrog cov ntaub thaiv. Lub gasket qhwv yog hais txog lub gasket uas qhwv ib yam khoom rau lwm yam khoom. Lub gasket zoo li no feem ntau muaj qhov elasticity zoo thiab tuaj yeem txhim kho qhov sealing effect. ④ Cov ntaub thaiv zoo li tus kheej. Cov ntaub thaiv zoo li tus kheej yog hais txog cov gaskets uas muaj cov duab tsis sib xws, suav nrog cov ntaub thaiv oval, cov ntaub thaiv pob zeb diamond, cov ntaub thaiv iav, cov ntaub thaiv dovetail, thiab lwm yam. Cov ntaub thaiv no feem ntau muaj qhov ua kom nruj thiab feem ntau siv rau hauv cov qhov siab thiab nruab nrab.
⑤ Lub tshuab ntxhua khaub ncaws nthwv dej. Cov gasket nthwv dej yog cov gaskets uas tsuas muaj cov duab nthwv dej xwb. Cov gaskets no feem ntau yog ua los ntawm kev sib xyaw ua ke ntawm cov khoom siv hlau thiab cov khoom siv tsis yog hlau. Lawv feem ntau muaj cov yam ntxwv ntawm lub zog nias me me thiab cov nyhuv sealing zoo.
⑥ Qhwv lub washer. Cov gaskets qhov txhab yog cov gaskets tsim los ntawm kev qhwv cov hlau nyias nyias thiab cov hlau tsis yog hlau ua ke nruj nreem. Hom gasket no muaj kev ywj pheej zoo thiab kev sib khi zoo. Cov ntaub ntawv rau kev ua gaskets feem ntau suav nrog peb pawg, uas yog cov khoom siv hlau, cov khoom siv tsis yog hlau thiab cov khoom sib xyaw. Feem ntau hais lus, cov khoom siv hlau muaj lub zog siab thiab tiv taus kub zoo. Cov khoom siv hlau feem ntau siv suav nrog tooj liab, txhuas, hlau, thiab lwm yam. Muaj ntau hom khoom siv tsis yog hlau, suav nrog cov khoom yas, cov khoom siv roj hmab, cov khoom asbestos, cov khoom hemp, thiab lwm yam. Cov khoom siv tsis yog hlau no siv dav thiab tuaj yeem xaiv raws li qhov xav tau tshwj xeeb. Kuj tseem muaj ntau hom khoom siv sib xyaw, suav nrog laminates, composite panels, thiab lwm yam, uas kuj raug xaiv raws li qhov xav tau tshwj xeeb. Feem ntau, corrugated washers thiab spiral wound washers feem ntau siv.

2. Lub foob pob hluav taws xob

Dynamic seal yog hais txog lub foob uas tiv thaiv cov dej ntws nruab nrab hauv lub valve kom tsis txhob xau nrog kev txav ntawm lub qia valve. Qhov no yog qhov teeb meem sealing thaum lub sijhawm txav mus los. Txoj kev sealing tseem ceeb yog lub thawv ntim khoom. Muaj ob hom thawv ntim khoom yooj yim: hom gland thiab hom compression nut. Hom gland yog hom siv ntau tshaj plaws tam sim no. Feem ntau, hais txog daim ntawv ntawm lub gland, nws tuaj yeem muab faib ua ob hom: hom sib xyaw thiab hom integral. Txawm hais tias txhua daim ntawv txawv, lawv feem ntau suav nrog bolts rau compression. Hom compression nut feem ntau siv rau cov valves me dua. Vim yog qhov me me ntawm hom no, lub zog compression yog txwv.
Hauv lub thawv ntim khoom, vim tias cov khoom ntim khoom sib txuas ncaj qha nrog lub qia valve, cov khoom ntim khoom yuav tsum muaj kev sib khi zoo, kev sib txhuam me me, tuaj yeem hloov kho rau qhov siab thiab kub ntawm qhov nruab nrab, thiab tiv taus xeb. Tam sim no, cov khoom ntim khoom siv feem ntau suav nrog roj hmab O-rings, polytetrafluoroethylene braided packing, asbestos packing thiab yas molding fillers. Txhua qhov khoom ntim khoom muaj nws tus kheej cov xwm txheej thiab ntau yam, thiab yuav tsum tau xaiv raws li qhov xav tau tshwj xeeb. Kev sib khi yog los tiv thaiv kev xau, yog li lub hauv paus ntsiab lus ntawm kev sib khi valve kuj raug kawm los ntawm qhov pom ntawm kev tiv thaiv kev xau. Muaj ob qho tseem ceeb ua rau muaj kev xau. Ib qho yog qhov tseem ceeb tshaj plaws cuam tshuam rau kev ua haujlwm sib khi, uas yog, qhov sib txawv ntawm cov khub sib khi, thiab qhov sib txawv yog qhov sib txawv ntawm ob sab ntawm cov khub sib khi. Lub hauv paus ntsiab lus ntawm kev sib khi valve kuj raug soj ntsuam los ntawm plaub yam: kev sib khi kua, kev sib khi roj, kev sib khi channel xau thiab khub sib khi valve.

Kev nruj ntawm kua

Cov yam ntxwv ntawm kev sib khi ntawm cov kua yog txiav txim siab los ntawm qhov viscosity thiab qhov nro ntawm qhov chaw ntawm cov kua. Thaum lub capillary ntawm lub valve xau puv nrog roj, qhov nro ntawm qhov chaw yuav thawb cov kua lossis coj cov kua rau hauv lub capillary. Qhov no tsim lub kaum sab xis tangent. Thaum lub kaum sab xis tangent tsawg dua 90 °, cov kua yuav raug txhaj rau hauv lub capillary, thiab qhov xau yuav tshwm sim. Qhov xau tshwm sim vim yog cov yam ntxwv sib txawv ntawm cov xov xwm. Kev sim siv cov xov xwm sib txawv yuav ua rau muaj txiaj ntsig sib txawv nyob rau hauv tib qho xwm txheej. Koj tuaj yeem siv dej, cua lossis kerosene, thiab lwm yam. Thaum lub kaum sab xis tangent ntau dua 90 °, qhov xau kuj yuav tshwm sim. Vim tias nws cuam tshuam nrog cov roj lossis cov roj pleev xim rau ntawm qhov chaw hlau. Thaum cov yeeb yaj kiab saum npoo no yaj, cov yam ntxwv ntawm qhov chaw hlau hloov pauv, thiab cov kua uas tau thawb thawj zaug yuav ntub qhov chaw thiab xau. Vim yog qhov xwm txheej saum toj no, raws li Poisson tus qauv, lub hom phiaj ntawm kev tiv thaiv kev xau lossis txo qhov ntau ntawm qhov xau tuaj yeem ua tiav los ntawm kev txo qhov capillary txoj kab uas hla thiab nce qhov viscosity ntawm qhov chaw.

Kev nruj ntawm cov roj

Raws li Poisson tus qauv, qhov nruj ntawm cov roj yog cuam tshuam nrog qhov viscosity ntawm cov roj molecules thiab cov roj. Kev xau yog inversely proportional rau qhov ntev ntawm lub raj capillary thiab qhov viscosity ntawm cov roj, thiab ncaj qha proportional rau txoj kab uas hla ntawm lub raj capillary thiab lub zog tsav. Thaum txoj kab uas hla ntawm lub raj capillary yog tib yam li qhov nruab nrab ntawm kev ywj pheej ntawm cov roj molecules, cov roj molecules yuav ntws mus rau hauv lub raj capillary nrog kev txav thermal dawb. Yog li ntawd, thaum peb ua qhov kev sim kaw lub valve, qhov nruab nrab yuav tsum yog dej kom ua tiav qhov cuam tshuam sealing, thiab cua, uas yog, roj, tsis tuaj yeem ua tiav qhov cuam tshuam sealing.

Txawm tias peb txo qhov capillary txoj kab uas hla hauv qab cov roj molecules los ntawm kev hloov pauv yas, peb tseem tsis tuaj yeem nres qhov ntws ntawm cov roj. Qhov laj thawj yog tias cov roj tseem tuaj yeem kis tau los ntawm cov phab ntsa hlau. Yog li ntawd, thaum peb ua qhov kev sim roj, peb yuav tsum nruj dua li qhov kev sim kua.

Lub hauv paus ntsiab lus ntawm kev sib khi ntawm cov channel xau

Lub foob valve muaj ob ntu: qhov tsis sib xws kis mus rau ntawm qhov nthwv dej thiab qhov roughness ntawm qhov nthwv dej nyob rau hauv qhov deb ntawm cov nthwv dej siab. Hauv qhov xwm txheej uas feem ntau ntawm cov khoom siv hlau hauv peb lub tebchaws muaj qhov tsis tshua muaj elastic strain, yog tias peb xav ua tiav lub xeev kaw, peb yuav tsum tsa cov kev cai siab dua ntawm lub zog compression ntawm cov khoom siv hlau, uas yog, lub zog compression ntawm cov khoom siv yuav tsum tshaj nws cov elasticity. Yog li ntawd, thaum tsim lub valve, cov khub sealing raug phim nrog qee qhov sib txawv hardness. Nyob rau hauv qhov kev ua ntawm siab, ib qho degree ntawm cov yas deformation sealing nyhuv yuav tsim.

Yog tias qhov chaw sib khi ua los ntawm cov khoom siv hlau, ces cov ntsiab lus tsis sib xws ntawm qhov chaw yuav tshwm sim sai tshaj plaws. Thaum pib, tsuas yog siv me me xwb thiaj li ua rau cov yas deformation ntawm cov ntsiab lus tsis sib xws no. Thaum qhov chaw sib cuag nce ntxiv, qhov tsis sib xws ntawm qhov chaw ua rau yas-elastic deformation. Lub sijhawm no, qhov roughness ntawm ob sab hauv qhov chaw yuav muaj. Thaum nws tsim nyog siv cov khoom thauj uas tuaj yeem ua rau cov yas deformation loj ntawm cov khoom hauv qab, thiab ua rau ob qhov chaw sib cuag ze, cov kev seem no tuaj yeem ua ze rau ntawm txoj kab txuas ntxiv thiab kev coj ncig.

Valve foob khub

Cov khub kaw lub valve yog ib feem ntawm lub rooj zaum valve thiab cov khoom kaw uas kaw thaum lawv sib chwv. Thaum siv, qhov chaw kaw hlau yooj yim puas tsuaj los ntawm cov khoom siv entrained, corrosion media, hnav cov khoom me me, cavitation thiab erosion. Xws li cov khoom hnav. Yog tias cov khoom hnav me dua qhov roughness ntawm qhov chaw, qhov tseeb ntawm qhov chaw yuav zoo dua es tsis txhob puas thaum qhov chaw kaw raug hnav. Ntawm qhov tsis sib xws, qhov tseeb ntawm qhov chaw yuav puas tsuaj. Yog li ntawd, thaum xaiv cov khoom hnav, cov yam xws li lawv cov ntaub ntawv, cov xwm txheej ua haujlwm, lubricity, thiab corrosion ntawm qhov chaw kaw yuav tsum tau txiav txim siab tag nrho.

Ib yam li cov khoom siv hnav, thaum peb xaiv cov foob, peb yuav tsum xav txog ntau yam uas cuam tshuam rau lawv txoj kev ua haujlwm kom tiv thaiv kev xau. Yog li ntawd, nws yog ib qho tsim nyog los xaiv cov ntaub ntawv uas tiv taus corrosion, khawb thiab yaig. Txwv tsis pub, qhov tsis muaj qhov yuav tsum tau ua yuav txo nws txoj kev ua haujlwm sealing.