Views: 837 Author: Site Editor Publish Time: 2023-12-18 Keeb Kwm: Qhov chaw
Koj puas muaj teeb meem los ntawm kev tsis nkag siab NPSM, NPTF, NPT, thiab BSPT xov? Kab lus no yuav qhia koj txog kev nkag siab ntxaws ntawm cov xov no, thiab qhia koj yuav ua li cas rau nruab lawv nrog rau cov kev xav tseem ceeb.
NPT sawv cev rau National Pipe Tapered . Nws yog ib hom tapered xov siv los koom nrog cov kav dej thiab fittings. Nov yog yam koj yuav tsum paub:
l Tapered Threads : NPT threads taper ntawm tus nqi ntawm 1/16 nti ib nti, uas txhais tau tias lawv nqaim mus rau qhov kawg.
l Xov Standards : Lawv ua raws li ANSI/ASME B1.20.1 tus qauv.
l Thread Angle : Cov xov muaj lub kaum sab xis ntawm 60 °.
l Sealing Efficiency : Lawv tsim lub tshuab foob los ntawm kev cuam tshuam haum ntawm cov xov crests thiab cov hauv paus hniav.
NPT threads nyob txhua qhov chaw hauv lub tshuab siab . Lawv yog siv los xyuas kom meej tias tsis muaj cov dej xau hauv:
l Kev Hloov Cov Dej thiab Roj : Cov kav dej uas nqa dej, roj, lossis roj.
l Pressure Calibration Systems : Cov khoom siv ntsuas qhov siab.
Kev lag luam uas siv NPT threads suav nrog:
l Kev tsim khoom
l Automotive
l Aerospace
Thaum txhim kho NPT threads, ua raws li cov kev coj ua zoo tshaj no:
1. Siv PTFE daim kab xev : qhwv PTFE daim kab xev (Teflon) nyob ib ncig ntawm tus txiv neej xov los txhim kho lub foob.
2. Tsis txhob dhau-Tighten : Tshaj-tightening tuaj yeem ua rau galling , qhov twg cov xov puas.
3. Tshawb xyuas cov Leaks : Ib txwm sim qhov kev sib txuas rau kev xau.
Common siv muaj xws li:
l Cov kav dej txuas : Zoo li hauv koj lub tsev cov kav dej.
l Fittings : Zoo li lub luj tshib lossis tees uas pab hloov cov kev taw qhia ntawm qhov ntws.
l Kev sib txuas tsis pub muaj : Lawv tsim los tsim kom muaj kev sib khi nruj.
l Txais Tau Txais : NPT yog tus qauv hauv ntau qhov kev lag luam.
l Risk of Over-Tightening : Nws tuaj yeem ua rau cov xov puas.
l Tej zaum yuav tsum tau muab cov sealant : Qee lub sij hawm, yuav tsum tau muab cov sealant ntxiv los xyuas kom meej lub foob tsis muaj paug.
l NPTF , los yog National Pipe Taper Roj , tseem hu ua Dryseal American National Standard Taper Yeeb Nkab Xov , yog tsim los muab lub foob nruj dua yam tsis tas yuav tsum muaj cov sealant ntxiv.
l NPTF threads muaj qhov sib txawv me ntsis uas tso cai rau kev sib txuas ntawm cov tshuab tsis siv PTFE daim kab xev lossis lwm yam sealants, tsis zoo li NPT threads uas feem ntau xav tau lawv.
Nco ntsoov, NPT yog hais txog kev tsim cov yeeb nkab txuas txuas uas txhim khu kev qha thiab siv dav. Txawm hais tias koj tab tom ua haujlwm ntawm lub tsheb lossis kho qhov xau hauv tsev, kev paub txog NPT xov pab koj ua kom muaj kev sib txuas zoo dua.
NPTF threads, tseem hu ua Dryseal American National Standard Taper Pipe Thread , ua raws li ANSI B1.20.3 tus qauv. Cov xov no zoo ib yam li NPT tab sis yog tsim los rau lub foob zoo dua. NPTF threads muaj 60 ° flank lub kaum sab xis thiab tsim cov khoom siv foob los ntawm kev cuam tshuam ntawm cov xov crests thiab cov hauv paus hniav. Qhov no txhais tau hais tias cov xov sib tsoo ua ke los ua ib qho kev sib khi nruj tsis tas yuav tsum tau sealants ntxiv.
Thaum NPT thiab NPTF xov zoo sib xws, lawv cov qauv tsim txawv . NPT threads yog tsim los ntawm ANSI / ASME B1.20.1 , thiab lawv yuav xav tau PTFE daim kab xev los yog lwm yam sealants kom ntseeg tau tias tsis muaj kev sib txuas . Ntawm qhov tod tes, NPTF threads, tom qab ANSI B1.20.3 , yog ua rau mesh tighter thiab tsim ib lub foob tsis muaj ntaub ntawv ntxiv. Lawv ua tiav qhov no los ntawm tus qauv tsim uas tso cai rau cov xov crests thiab cov hauv paus hniav kom squash ua ke, tsim kom muaj lub foob tsis muaj paug..
Hauv ntiaj teb cov roj thiab roj , NPTF threads yog ib qho kev xaiv. Lawv tau tsim los ua ib lub foob tsis muaj pa tawm uas yog qhov tseem ceeb hauv cov tshuab siab . Cov tshuab no tsis tuaj yeem them cov dej xau, txawm tias ib qho me me tuaj yeem ua rau muaj kev phom sij. NPTF threads yog siv nyob rau hauv lub siab calibration systems thiab qhov chaw uas tswj lub purity thiab kev ncaj ncees ntawm cov kua los yog roj yog tseem ceeb heev.
NPTF threads feem ntau pom muaj nyob rau hauv daim ntawv thov uas tsis muaj lub foob tsis muaj qhov tseem ceeb, thiab tsis xav tau sealant. Txawm li cas los xij, thaum NPTF thiab NPT xov tuaj yeem sib xyaw ua ke, qhov no tsis yog ib txwm muaj kev nyab xeeb lossis siv tau. NPTF threads tuaj yeem ntsia tau rau hauv NPT fittings, tab sis qhov thim rov qab yuav tsis kaw kom zoo vim NPTF yog tsim los kom haum zoo dua. Nws yog ib qho tseem ceeb uas yuav tau kuaj xyuas kev sib raug zoo ua ntej sib xyaw kom tsis txhob muaj teeb meem xws li galling lossis tsis raug sealing.
NPSM threads yog ib hom ntawm cov yeeb nkab ncaj . Lawv ua raws li ANSI/ASME B1.20.1 tus qauv. Cov xov no yog tsim los rau kev sib txuas ntawm cov neeg kho tshuab es tsis yog ua lub foob. Lawv muaj 60 ° flank lub kaum sab xis thiab txhais tau tias yuav tsum tau siv nrog lub gasket lossis O-ring los tsim kev sib txuas tsis muaj pa.
Cov ntsiab lus tseem ceeb ntawm NPSM threads: - Lawv yog cov sib npaug , uas txhais tau hais tias txoj kab uas hla zoo ib yam. - NPSM xov tsis taper zoo li NPT (National Pipe Tapered) xov. - Lawv yog siv los ua kev sib txuas tshuab . - Sealing efficiency los ntawm gaskets, tsis yog threads lawv tus kheej.
NPSM threads feem ntau pom muaj nyob rau hauv cov tshuab hydraulic uas tsis muaj lub foob tsis muaj qhov tseem ceeb. Lawv ua haujlwm zoo hauv cov tshuab siab xws li cov tshuab ntsuas siab . Cov Poj Niam Yeeb Nkab Swivel fittings feem ntau nrog NPSM xov, tso cai rau kev teeb tsa yooj yim hauv qhov chaw nruj.
Cov kev siv zoo tshaj plaws suav nrog: - Qhov twg lub tshuab foob yog qhov tseem ceeb tshaj li xov foob. - Cov kab ke yuav tsum tau nquag disassembly thiab reassembly. - Thaum siv lub gasket los yog O-ring yog nyiam tshaj xov sealant.
NPSM qee zaum tuaj yeem tsis meej pem nrog NPTF (National Pipe Taper Fuel), tseem hu ua Dryseal American National Standard Taper Pipe Thread . Nov yog qhov lawv sib piv:
l NPTF threads yog tsim los muab lub foob tsis muaj qhov tsis muaj qhov xav tau ntxiv sealants. Lawv tsim ib qho kev cuam tshuam haum ntawm cov xov crests thiab xov hauv paus.
l NPSM threads xav tau lub gasket lossis O-ring kom ntseeg tau tias tsis muaj kev sib txuas.
l NPSM tsis hloov pauv nrog NPTF lossis NPT vim yog cov qauv xov sib txawv.
NPSM threads muaj nuj nqis rau lawv cov kev sib khi ua haujlwm thaum siv nrog lub tshuab foob kom raug . Lawv tau siv dav hauv: - kua thiab roj hloov daim ntawv thov. - Kev lag luam uas xav tau kev sib txuas ua ke txhim khu kev qha.
Cov ntawv thov kev lag luam muaj xws li: - Kev kho dej thiab dej khib nyiab. - Pneumatic systems. - Lubrication systems.
Thaum peb tham txog BSPT xov , peb tab tom dhia mus rau hauv lub ntiaj teb ntawm cov kav dej thiab kev sib txuas uas yog qhov tseem ceeb rau kev hloov pauv dej thiab roj . BSPT stands rau British Standard Pipe Taper . Nws yog ib hom kab tapered siv los ua kom tsis muaj dej ntws tawm . Cov qauv no tau teev tseg hauv cov ntaub ntawv xws li BS 21 thiab ISO 7.
BSPT threads yog tshwj xeeb. Lawv muaj lub kaum sab xis ntawm 60 ° thiab yog tapered, uas txhais tau hais tias lawv nqaim dua thaum lawv mus tob. Qhov no txawv ntawm NPT threads , uas tseem tapered tab sis muaj 60 ° xov lub kaum sab xis siv nyob rau hauv America, raws li tau txhais los ntawm ANSI/ASME B1.20.1.
Tam sim no, cia peb piv BSPT nrog NPTF . NPTF, los yog National Pipe Taper Roj , feem ntau hu ua Dryseal American National Standard Taper Yeeb Nkab Xov , raws li ANSI B1.20.3 , yog tsim los rau lub foob nruj dua NPT. Nws ua tiav qhov no los ntawm kev tsim kom muaj kev cuam tshuam ntawm cov xov crests thiab xov hauv paus . BSPT tsis cia siab rau qhov haum rau kev sib khi. Hloov chaw, nws yuav xav tau cov xov sealant zoo li PTFE daim kab xev (Teflon) lossis lub gasket los tiv thaiv kom tsis txhob xau.
BSPT threads tau dav siv sab nraum Tebchaws Meskas, tshwj xeeb tshaj yog nyob rau hauv cov tebchaws uas ua raws li British engineering qauv. Lawv feem ntau pom nyob rau hauv lub tshuab siab thiab siab calibration systems . Lawv lub peev xwm los tsim lub tshuab foob ua rau lawv haum rau ntau daim ntawv thov thoob ntiaj teb.
Thaum peb saib BSPT nrog rau lwm hom xov xws li NPSM (National Pipe Straight Mechanical) thiab BSPP (British Standard Parallel Pipe) , peb pom tias BSPT yog tsim kom muaj kev sib txuas tsis pub muaj kev sib txuas hauv cov xov tapered, thaum NPSM thiab BSPP yog rau cov yeeb nkab ncaj . BSPT threads ua ib qho kev sib txuas tsis tas yuav tsum muaj lub nplhaib sib khi lossis O-ring , tsis zoo li BSPP uas yuav xav tau cov no rau kev sib khi.
BSPT threads yog qhov zoo rau cov xwm txheej uas koj xav tau cov khoom ruaj khov, tsis muaj qhov tsis muaj qhov tsis muaj qhov nyuaj ntawm lwm txoj kev sib khi. Lawv siv tau yooj yim dua li NPTF threads , uas yuav tsum tau muaj kev ntsuas siab kom tsis txhob muaj teeb meem xws li galling lossis puas los ntawm kev nruj dua.
Thaum peb tham txog xov fittings xws li NPSM, NPTF, NPT, thiab BSPT, nws yog txhua yam hais txog yuav ua li cas lawv txuas thiab kaw cov kav dej. no Cov qauv xov pab peb kom paub tseeb tias cov khoom haum ua ke zoo. Xav txog nws zoo li LEGO blocks - lawv yuav tsum sib phim zoo kawg nkaus los ua ke.
l NPSM thiab NPS muaj cov xov ncaj, uas txhais tau tias lawv tsis tau nruj dua li lawv ntsia hlau.
l NPT , NPTF , thiab BSPT yog tapered. Qhov no txhais tau hais tias lawv tau nruj dua, zoo li lub funnel, uas pab kom tsis txhob xau.
Lub koom haum American National Standards Institute (ANSI) tau teeb tsa cov cai rau cov xov no hauv Teb Chaws Asmeskas Piv txwv li, ANSI/ASME B1.20.1 yog rau NPT threads. Lawv qhia peb tias cov xov yuav tsum loj npaum li cas, muaj pes tsawg tus hauv ib nti (uas yog cov xov suav), thiab cov duab lawv yuav tsum muaj.
Cov ntaub ntawv tseem ceeb heev. Feem ntau cov fittings yog hlau, xws li hlau los yog tooj dag, vim lawv muaj zog. Kev tsim cov khoom no ua raws cov cai nruj kom ntseeg tau tias lawv muaj kev nyab xeeb thiab yuav kav ntev. Qhov no yog hais txog kev ua raws cai - zoo li ua raws li daim ntawv qhia kom ci lub ncuav mog qab zib zoo meej txhua lub sijhawm.
l ANSI B1.20.3 thiab AS 1722.1 yog qee cov qauv uas qhia yuav ua li cas cov xov rau lub tshuab siab.
l Hauv UK, lawv siv BS 21 thiab ISO 7 rau BSPT thiab BSPP xov.
Cov neeg tsim khoom kuj yuav tsum tau ua kom lawv cov xov tuaj yeem tswj tau lub siab uas lawv yuav tsum tsis txhob tawg lossis tawg. Qhov ntawd yog qhov kev lees paub zoo tuaj.
Xov qhov ntev muaj xws li lub suab (sib nrug deb npaum li cas cov xov yog) thiab lub kaum sab xis ntawm cov xov. Piv txwv li, BSPT threads muaj 60 ° flank lub kaum sab xis , uas yog ib feem ntawm qhov ua rau lawv tshwj xeeb.
l Tolerances yog qhov sib txawv me me pub rau qhov loj thiab cov duab ntawm cov xov. Lawv zoo li lub wiggle chav nyob rau hauv haum tej daim ua ke.
l Kev ruaj ntseg zoo txhais tau tias kuaj xyuas txhua qhov kom paub tseeb tias nws ua tau raws li cov qauv. Nws zoo li tus kws qhia ntawv muab koj cov ntawv ua tom tsev kom paub tseeb tias koj tau txais cov lus teb raug.
Rau lub foob tsis muaj paug , qhov chaw xws li PTFE daim kab xev (Teflon) , gaskets , lossis O-rings yuav siv nrog cov xov no. Tapered threads zoo li NPT thiab BSPT feem ntau tuaj yeem kaw ntawm lawv tus kheej vim lawv cov duab - lawv tau nruj dua thiab nruj dua li lawv tau ntsia hauv.
l NPT threads yog tsim los ua ib qho kev cuam tshuam , uas txhais tau hais tias lawv tsim ib lub tshuab foob los ntawm squeezing ua ke.
l NPSM threads ua hauj lwm nrog ib tug poj niam yeeb nkab swivel - ib hom txiv ntseej uas cia koj ntsia hlau rau nws yam tsis tau twisting tag nrho cov yeeb nkab.
l NPTF threads yog qee zaum hu ua Dryseal American National Standard Taper Yeeb Nkab Xov vim tias lawv txhais tau tias yuav tsum tau ntim yam tsis xav tau cov khoom ntxiv xws li daim kab xev lossis muab tshuaj txhuam.
Thaum nws los txog rau xov fittings siv nyob rau hauv siab systems , cov ntsiab lus tseem ceeb. Cia peb saib seb cov xov no siv li cas hauv lub ntiaj teb tiag.
NPT threads feem ntau pom muaj nyob rau hauv cov ntawv thov kev lag luam. Piv txwv li, cov chaw tsim khoom ntawm lub tshuab ntsuas siab yuav siv NPT fittings vim tias lawv sib raug zoo nrog ntau yam khoom siv.
NPTF threads , tseem hu ua Dryseal American National Standard Taper Yeeb Nkab Xov , yog tsim los kom muaj kev ruaj ntseg ntau dua, tsis muaj kev sib khi tsis tas yuav tsum muaj xov txuas ntxiv . Lawv tau siv rau hauv cov ntawv thov uas lub tshuab foob yog qhov tseem ceeb, zoo li hauv cov khoom siv roj.
NPSM threads , los yog National Pipe Straight Mechanical , feem ntau yog siv nrog ib tug poj niam yeeb nkab swivel . Cov ntaub ntawv kawm yuav suav nrog lub tshuab hydraulic uas NPSM fittings tso cai rau kev sib dhos yooj yim dua thiab txij nkawm.
BSPT threads , nrog rau lawv 60 ° flank lub kaum sab xis , muaj ntau nyob rau hauv kev siv thoob ntiaj teb. Lawv feem ntau xaiv rau lawv cov kev sib khi ua haujlwm hauv cov kua thiab cov pa hloov pauv.
Wb rhuav tshem qhov sib txawv:
l NPT vs. NPTF : Ob leeg muaj ib lub yeeb nkab xov , tab sis NPTF muab kev cuam tshuam haum ntawm cov xov crests thiab xov hauv paus , tshem tawm qhov xav tau rau lub sealant.
l NPSM vs. NPT : NPSM muaj cov yeeb nkab ncaj nraim thiab yuav tsum tau lub gasket los yog O-ring los tsim kom muaj kev sib txuas tsis muaj dej . NPT's tapered threads tsim ib lub foob los ntawm cov xov lawv tus kheej.
l BSPT Txoj Haujlwm Tshwj Xeeb : BSPT xov zoo ib yam li NPT tab sis muaj cov xov sib txawv thiab suab , ua rau lawv tsis sib hloov nrog NPT fittings.
Cov kws tshaj lij hauv kev lag luam tau hais kom siv PTFE daim kab xev (Teflon) los yog lub nplhaib sib txuas nrog NPT fittings los xyuas kom meej tias tsis muaj cov foob . Rau NPTF, nws yog ib qho tseem ceeb kom ntseeg tau tias muaj kev koom tes zoo los ua kom zoo dua ntawm nws txoj haujlwm dryseal .
Thaum ua haujlwm nrog BSPT kev sib txuas , nco ntsoov tias lawv tsis sib xws nrog NPT lossis NPTF yam tsis muaj cov khoom siv hloov pauv. Cov kws tshaj lij qhia txog kev txheeb xyuas cov qauv xov zoo li ANSI / ASME B1.20.1 rau NPT, ANSI B1.20.3 rau NPTF, lossis ISO 7 thiab BS 21 rau BSPT kom haum haum.
Galling , los yog xov puas, yog qhov txaus ntshai nrog cov fittings. Txhawm rau tiv thaiv nws, tsis txhob nruj nruj thiab ib txwm ua raws li cov txheej txheem siab ' specifications.
Thaum txhim kho NPSM , NPTF , NPT , los yog BSPT fittings, nws yog ib qho tseem ceeb kom ua raws li cov lus qhia tshwj xeeb kom ntseeg tau tias tsis muaj kev sib txuas . Nov yog phau ntawv qhia ceev:
l NPT thiab NPTF :
l Thov PTFE daim kab xev los yog ib haum txoj hlua rau cov txiv neej xov.
l Tighten lub fitting ntawm tes, ces siv ib tug wrench rau zaum kawg lem.
l Ceev faj tsis txhob nruj, vim qhov no tuaj yeem ua rau cov xov puas.
l BSPT :
l Zoo ib yam li NPT, siv PTFE daim kab xev los yog xov sealant.
l Tighten ua tib zoo kom ua tiav lub tshuab foob.
l NPSM :
l Cov xov no yog tsim los ua phooj ywg nrog poj niam cov yeeb nkab tig.
l Siv lub gasket los yog O-ring rau sealing.
l Tsis txhob overtighten, vim nws tuaj yeem ua rau lub gasket puas.
l Hla-threading : tshwm sim thaum cov xov tsis sib haum. Ib txwm pib ntawm tes los tiv thaiv nws.
l Galling : Hlau-rau-hlau sib cuag tuaj yeem ua rau qhov no. Siv lubrication kom tsis txhob nws.
l Tshaj-tightening : tuaj yeem ua rau xov puas. Ua raws li cov txheej txheem siab calibration systems kom tsim nyog torque.
l Cov dej xau : Yog tias cov dej xau tshwm sim, xyuas kom tsis txhob muaj qhov sib npaug thiab xyuas kom muaj kev sib koom tes zoo.
l Kev tshuaj xyuas tsis tu ncua : Tshawb xyuas cov cim ntawm hnav, corrosion, lossis puas.
l Ntxuav : Khaws cov xov kom huv. Cov av tuaj yeem ua rau xau.
l Reapplication of Sealant : Thaum lub sij hawm, sealants tuaj yeem degrade. Rov thov dua raws li xav tau.
l Cia kom zoo : Khaws cov khoom seem hauv qhov chaw qhuav, huv si.
Nco ntsoov :
l NPT thiab NPTF threads tsim ib lub foob los ntawm kev cuam tshuam haum ntawm cov xov crests thiab cov hauv paus hniav.
l BSPT threads foob los ntawm cov xov ib leeg, nrog rau 60 ° flank lub kaum sab xis pab hauv kev sib khi ua haujlwm.
l NPSM threads vam khom rau kev sib txuas , feem ntau txhim kho nrog lub gasket lossis O-ring.
Thaum nws los txog rau xov fittings , nws zoo li ib tug puzzle. Txhua daim haum nyob rau hauv ib txoj kev. NPSM (National Pipe Straight Mechanical) threads yog ncaj thiab tsim los rau kev sib koom ua haujlwm pub dawb. NPT (National Pipe Tapered) threads yog tapered thiab ua kom nruj nruj los ntawm kev sib sib zog nqus sib sib zog nqus raws li lawv tau screwed nyob rau hauv. NPTF (National Pipe Taper Fuel), tseem hu ua Dryseal American National Standard Taper Yeeb Nkab Xov , zoo ib yam li NPT tab sis tsim los rau lub foob zoo dua yam tsis xav tau ntxiv sealant. BSPT (British Standard Pipe Taper) threads, ntawm qhov tod tes, yog siv los ua cov ntsaws ruaj ruaj hauv cov tshuab siab thiab muaj lub kaum sab xis 55 °, txawv ntawm 60 ° lub kaum sab xis siv hauv NPT threads.
Tam sim no, koj tuaj yeem sib tov lawv? Tsis yog tiag. Interchangeability tsis yog ib qho kev ua si uas koj xav ua si nrog xov fittings. Siv NPT nrog NPTF qee zaum tuaj yeem ua haujlwm, tab sis nws tsis tau lees tias yog qhov tsis muaj kev sib txuas . Thiab BSPT ? Nws yog tag nrho cov dab neeg sib txawv vim nws qhov tshwj xeeb xov lub kaum sab xis thiab suab. Qhov feem ntau yuam kev? Xav tias lawv txhua tus haum ua ke. Nco ntsoov xyuas cov qauv, xws li ANSI/ASME B1.20.1 rau NPT, kom tsis txhob muaj kev puas tsuaj.
Yog li, koj yuav xaiv qhov zoo li cas? Xav txog txoj haujlwm. Rau cov kua dej thiab cov pa hloov pauv , lub foob tsis muaj pa tawm yog qhov tseem ceeb. Yog tias koj ua haujlwm nrog lub tshuab siab , BSPT tej zaum yuav yog txoj hauv kev mus. Rau cov ntawv thov uas xav tau lub tshuab foob yam tsis muaj sealant, NPTF yog koj tus phooj ywg. Thiab rau kev sib txuas ntawm cov tshuab uas tuaj yeem sib cais yooj yim, NPSM tuaj yeem yog qhov kev xaiv zoo tshaj plaws.
l Dab tsi yog sealant zoo?
PTFE daim kab xev (Teflon) feem ntau yog siv nrog NPT threads los pab foob.
l Kuv yuav tsum ceev npaum li cas?
Mus rau qhov cuam tshuam haum - nruj txaus kom cov xov crests thiab cov hauv paus hniav nias ua ke, tab sis tsis nruj heev uas koj hlais cov xov.
l Yuav ua li cas yog lub kaum sab xis?
Nco ntsoov, NPT thiab NPTF muaj lub kaum sab xis 60 ° , thiab BSPT muaj 55 ° lub kaum sab xis.
l Kuv puas tuaj yeem rov siv cov fittings no?
Qee lub sij hawm, tab sis saib xyuas rau qhov galling - thaum threads hnav thiab lo ua ke.
l Yuav ua li cas yog nws xau?
Txheeb xyuas qhov kev puas tsuaj los yog sim lub nplhaib sib khi los yog O-ring rau ib txheej ntxiv ntawm kev tiv thaiv.
Nco ntsoov, tau txais qhov haum yog zoo li xaiv cov cuab yeej tsim nyog rau txoj haujlwm. Nws yog txhua yam hais txog cov ntsiab lus. Khaws cov lus qhia no hauv siab, thiab koj yuav nyob ntawm koj txoj hauv kev kom paub cov xov fittings rau kev sib txuas tsis muaj paug.
Thaum peb tham txog xov fittings zoo li NPSM , NPTF , NPT , thiab BSPT , peb tab tom tham txog cov khoom uas pab peb koom nrog cov kav dej thiab hoses ua ke. Cov fittings no ua kom peb cov dej, roj, thiab lwm yam khoom txav mus los ntawm cov kav dej yam tsis muaj dej. Nov yog yam peb tau kawm:
l NPT yog ib hom kab tapered siv ntau hauv Asmeskas. Nws ua rau nruj haum vim cov xov me me ntawm ib kawg, zoo li lub khob hliav qab.
l NPTF , tseem hu ua Dryseal American National Standard Taper Yeeb Nkab Xov , zoo li NPT tab sis tsim los ua kom muaj kev sib khi ruaj khov dua yam tsis xav tau cov khoom ntxiv xws li PTFE daim kab xev..
l NPSM , los yog National Pipe Straight Mechanical , muaj cov yeeb nkab ncaj . Nws yog qhov zoo rau kev ua kom muaj kev sib txuas ntawm cov tshuab uas tuaj yeem sib cais thiab muab rov qab ua ke yooj yim.
l BSPT , luv luv rau British Standard Pipe Taper , zoo ib yam li NPT tab sis muaj cov xov sib txawv thiab suab . Nws muaj nyob rau hauv cov chaw uas siv cov qauv British.
Nco ntsoov, tau txais qhov haum zoo txhais tau tias paub txog koj cov qauv xov thiab xaiv hom zoo rau koj lub tshuab siab.
Lub ntiaj teb ntawm xov fittings yuav hloov. Nov yog dab tsi ntawm lub qab ntug:
l Sealing efficiency tau zoo dua. Peb tab tom nrhiav txoj hauv kev los ua kev sib txuas uas nruj heev yam tsis tas yuav tsum tau gaskets lossis O-rings ntxiv.
l Cov ntaub ntawv tseem tab tom txhim kho, ib yam nkaus. Qhov no txhais tau hais tias fittings tuaj yeem tswj tau ntau lub zog thiab kav ntev dua.
l Cov kws tshaj lij qhia ib txwm ua raws li cov lus pom zoo hauv kev lag luam , xws li siv ANSI / ASME B1.20.1 rau NPT lossis ISO 7 rau BSPT, kom paub tseeb tias txhua yam haum zoo.
