Valve yog ib qho tseem ceeb hauv cov kav dej ntawm cov nroj tsuag petrochemical. Nws muaj ntau hom thiab ntau ntau. Nws yog ib qho ntawm cov xau tseem ceeb hauv cov nroj tsuag. Yog li ntawd, qhov kev xav tau ntawm lub valve yog qhov tseem ceeb heev. Lub sealing kev ua tau zoo ntawm lub valve yog hais txog lub peev xwm ntawm lub sealing qhov chaw ntawm lub valve los tiv thaiv cov pa tawm ntawm qhov nruab nrab.
Lub ntsiab sealing qhov chaw ntawm lub valve yog: qhov sib txuam nto ntawm qhov qhib thiab kaw qhov chaw thiab lub rooj zaum valve, kev koom tes ntawm kev ntim khoom thiab lub valve qia thiab lub thawv ntim khoom, thiab kev sib txuas ntawm lub valve lub cev thiab lub valve npog. Thawj qhov xau yog hu ua kev xau sab hauv, uas cuam tshuam ncaj qha rau lub peev xwm ntawm lub valve txiav tawm qhov nruab nrab thiab kev ua haujlwm ntawm cov khoom siv. Cov dej xau nyob rau hauv ob qhov chaw tom qab no yog hu ua sab nraud to, uas yog, qhov nruab nrab ntawm cov xau los ntawm sab hauv ntawm lub valve mus rau sab nraud ntawm lub valve, uas ncaj qha cuam tshuam rau kev nyab xeeb ntau lawm, ua rau poob ntawm kev ua haujlwm nruab nrab, kev lag luam poob ntawm kev lag luam, ib puag ncig. muaj kuab paug, thiab kev tsim khoom raug tsim txom hauv cov xwm txheej hnyav. Tshwj xeeb tshaj yog rau qhov kub thiab txias siab, flammable, explosive, lom los yog corrosive xov xwm, lub sab nraud to ntawm lub valve yog tsis tso cai rau tag nrho cov, vim hais tias qhov tshwm sim yog heev loj tshaj lub sab hauv to, li ntawd, lub valve yuav tsum muaj kev ruaj ntseg sealing kev ua tau zoo kom tau raws li qhov yuav tsum tau. nws cov cai. Cov kev xav tau rau kev xau hauv kev ua haujlwm.
1 Kev faib tawm tus qauv ntawm lub valve sealing qib hauv kuv lub tebchaws
Tam sim no, feem ntau siv valve sealing qib cov qauv hauv kuv lub teb chaws feem ntau suav nrog ob qho hauv qab no.
1.1 Kev faib tawm ntawm cov qib sib khi valve los ntawm Suav teb cov qauv Lub teb chaws tus qauv GB / T 13927 "Pressure Test for Industrial Valves".
1.2 Kev faib tawm ntawm valve sealing qib los ntawm Suav machinery kev lag luam qauv Machinery kev lag luam tus qauv JB / T 9092 "Valve Inspection thiab Test".
2 Cov qauv kev faib tawm thoob ntiaj teb rau qib valve sealing
Tam sim no, feem ntau siv valve sealing qib kev faib cov qauv yog cov nram qab no tsib.
2.1 Kev faib tawm ntawm cov qib valve sealing nyob rau hauv lub qub Soviet Union
Txhawm rau xaiv cov khoom raws li qib kev sib khi ntawm lub valve thiab kev siv tshwj xeeb, cov li qub tau muab cais raws li qib kev sib khi.
2.2 Kev faib tawm ntawm cov qib sealing valve los ntawm International Organization for Standardization
International Organization for Standardization Standard ISO 5208 "Kev Ntsuas Siab ntawm Cov Hlau Hlau rau Kev Lag Luam Li Qub".
2.3 American Petroleum Institute (APl) kev faib tawm ntawm valve sealing qib American Petroleum Institute standard API 598--2004 "Valve Inspection and Test".
2.4 American Valve thiab Fittings Industry Manufacturers Standardization Society (MSS) kev faib tawm ntawm valve sealing qib Lub American Valve thiab Fittings Industry Manufacturers Standardization Society tus qauv "Pressure Test of Steel Valves" MSS SP61 tso cai rau lub valve xau raws li hauv qab no:
(1) Nyob rau hauv rooj plaub uas siv cov yas los yog roj hmab rau ib qho ntawm qhov chaw sib khi ntawm lub valve sealing khub, yuav tsum tsis txhob pom qhov xau rau lub sijhawm ntawm kev sib khi.
(2) Qhov siab tshaj plaws tso pa tawm ntawm txhua sab thaum kaw yuav tsum yog: kua yog nominal loj (DN) ib hli, 0.4 ml ib teev; gas yog nominal loj (DN) ib hli, 120 ml ib teev.
(3) Qhov tso cai tso tawm ntawm lub pob valve tuaj yeem nce 4 zaug.
2.5 American National Standard/American Instrument Institute Standard (ANSI/FCI) kev faib tawm ntawm kev tswj valve sealing qib
American National Standard American Instrument Association Standard ANSI/FCI70-2 (ASME B16.104) "Control Valve Seat Leakage".
2.6 Kev faib tawm ntawm cov qib sealing los ntawm EU cov qauv
European Standard EN 12266-1 "Kev Ntsuas Ntawm Cov Valves" Tshooj l. Kev Ntsuas Siab, Kev Ntsuas Kev Ntsuas thiab Kev Pom Zoo - Yuav Tsum Tau Ua.
3 Kev xaiv valve sealing qib
3.1 Kev xaiv cov khoom siv valve sealing qib
(1) Lub teb chaws tus qauv GB / T13927 ((Industrial Valve Siab Test) siv nyob rau hauv Lub Xya hli ntuj 1, 2009 yog formulated nrog rau cov European txheem ISO 5208. Nws yog haum rau industrial hlau li qub, xws li rooj vag li qub, ntiaj teb li qub, kos li qub. , cocks Kev tshuaj xyuas thiab kev ntsuas siab ntawm cov li qub, pob li qub thiab npauj npaim li qub.Qhov kev faib tawm thiab qhov siab tshaj plaws tso cai rau kev sib khi ntawm qhov kev sim sealing yog tib yam li cov teev hauv ISO 5208. Cov qauv no yog kev kho dua tshiab ntawm GB / T13927 (General Valve Siab Test, piv nrog GB / T13927, Rau qib tshiab AA, CC, E, EE, F thiab G tau ntxiv. Cov qauv tshiab ntawm tus qauv tau teev tseg tias "kev xaiv ntawm qib to yuav tsum yog ib qho ntawm cov kev cai nruj dua hauv cov khoom siv valve. Yog tias tsis muaj kev cai tshwj xeeb, cov khoom tsis yog xim hlau elastic sealing valve yuav tsum ua raws li cov kev cai A-theem, thiab cov hlau-sealed auxiliary li qub yuav tsum ua raws li kev cai. e nrog D-theem yuav tsum tau." Feem ntau, D-theem li qub yog tsim rau cov li qub, thiab ntau qhov tseem ceeb yuav tsum siv D-theem to los yog siab dua.
(2) Cov txheej txheem kev lag luam kev lag luam JB / T 9092 "Valve Inspection thiab Test" yog kev hloov kho rau ZB J16006. Qhov siab tshaj plaws tso cai tso cai ntawm kev ntsuas foob yog raws li American Petroleum Institute tus qauv API598--1996. Nws yog qhov tsim nyog rau kev tshuaj xyuas thiab kev ntsuas siab ntawm cov li qub rau kev lag luam roj av, suav nrog cov hlau sealing khub, elastic sealing khub thiab tsis yog xim hlau sealing khub (xws li ceramics), rooj vag li qub, lub ntiaj teb li qub, ntsaws li qub, pob li qub, kos li qub thiab npauj npaim. li qub. Tam sim no GB / T 9092 tab tom hloov kho.
(3) Kev saib xyuas yuav tsum tau them rau kev tsim qauv engineering: lub teb chaws tus qauv GB / T19672 (Technical Conditions for Pipeline Valves) yog tsim los nrog kev siv rau European standard ISO 14313 thiab American Petroleum Institute standard API 6D. "Pipeline Valve" yog tsim los nrog kev siv rau European tus qauv ISO 14313. Cov qauv kev lees paub rau lub valve leakage hauv GB / T 19672 thiab GB / T 20173 yog tib yam li ISO 5208 Class A thiab Class D cov cai. Yog li ntawd, muaj qib siab ntawm engineering tsim. Thaum cov txheej txheem xau yog xav tau, nws yuav tsum tau muab rau hauv daim ntawv cog lus txiav txim.
3.2 Xaiv qhov txawv teb chaws valve sealing qib
(1) Kev faib tawm ntawm cov qib valve sealing nyob rau hauv lub qub Soviet Union feem ntau yog siv nyob rau hauv 1950s. Nrog rau kev tawg ntawm lub qub Soviet Union, feem ntau lub teb chaws tsis siv qhov kev faib tawm ntawm cov qib sealing, tab sis siv European thiab American standard seals.
Seal classification. Cov txheej txheem European EN 12266-1 sealing grade classifications ua raws li cov kev cai ntawm International Organization for Standardization standard ISO 5208, tab sis tsis muaj peb qib AA, CC thiab EE. Piv nrog rau xyoo 1999, ISO 5208 tau ntxiv rau qib tshiab: AA, CC, E, EE, F thiab G. Tus qauv ISO 5208 muab kev sib piv ntawm ntau chav foob nrog API 598 thiab EN 12266 tus qauv.
④. Kev sib piv ntawm cov qib sealing ntawm lwm qhov nominal qhov ntau thiab tsawg tuaj yeem tau los ntawm kev suav cov xau los ntawm caliber.
(2) American Petroleum Institute tus qauv API 598 yog qhov feem ntau siv tshuaj ntsuam xyuas thiab ntsuas ntsuas tus qauv rau American Standard li qub. Cov chaw tsim khoom tus qauv MSSSP61 feem ntau yog siv rau kev tshuaj xyuas ntawm "tag nrho qhib" thiab "tag nrho kaw" steel li qub, tab sis
Tsis haum rau tswj li qub. American Standard li qub feem ntau tsis siv MSS SP61 tshuaj xyuas. API 598 muaj feem xyuam rau kev ntsuas kev ua tau zoo ntawm cov li qub uas tsim los rau API cov qauv hauv qab no:
Flanged, Lug, Wafer thiab Butt Welded Check Valves API 594
Hlau Plug Valves nrog Flanged, Threaded thiab Butt Welded Txuas Txuas API 599
Steel Gate Valves Globe thiab Kos Valves ntawm DNl00 thiab Hauv qab rau Roj thiab Roj Kev Lag Luam API 602
Corrosion Resistant Bolted Bonnet Gate Valves nrog Flanged thiab Butt Welded Txuas Txuas API 603
Hlau Pob Valves nrog Flanged, Threaded thiab Butt Welded Txuas Txuas API 608
Ob chav Flanged, Lug thiab Wafer Npauj Npaim Valve APl609
Nws yuav tsum raug sau tseg hauv kev tsim qauv engineering: API 598--2004, piv nrog xyoo 1996, tshem tawm qhov kev tshuaj xyuas thiab kev ntsuas siab ntawm API 600 ((bolted bonnet steel rooj vag valve rau kev lag luam roj thiab roj). API 600-2001 (ISO 10434 --1998) tus qauv qhia tias qhov kev sib khi ua tau zoo ntawm lub valve yog hais txog ISO 5208, tab sis qhov xau hauv Table 17 thiab Table 18 hauv tus qauv yog tib yam li tau teev tseg hauv API 598--1996 tus qauv , es tsis yog cov txheej txheem ntawm kev sib khi ntawm ISO5208. Cuaj hlis 2009 API 600 tus qauv siv rau lub Ib Hlis 13 tau kho qhov kev tsis sib haum xeeb hauv xyoo 2001, uas tau teev tseg tias kev ntsuas kev sib khi ntawm lub valve yog raws li API 598, tab sis muaj yog tsis tau teev version, uas dua contradicted API 598--2004. Yog li ntawd, engineering tsim xaiv API 600 thiab nws sealing kev xeem API 598 yuav tsum tau hais kom meej lub version ntawm tus txheej txheem los xyuas kom meej lub uniformity ntawm tus qauv cov ntsiab lus.
(3) Lub koom haum American Petroleum tus qauv API 6D (ISO14313) "Oil thiab Gas Industry-Pipeline Transmission System-Pipeline Valves" lees txais lub valve to raws li hauv qab no: "Cov dej ntws ntawm cov mos-sealed li qub thiab cov roj ntim cov ntsaws li qub yuav tsum tsis pub tshaj. TS EN ISO 5208 A Class D (tsis pom qhov xau), qhov xau ntawm lub rooj zaum hlau yuav tsum tsis pub tshaj ISO 5208 (1993) Chav Kawm D, tab sis raws li kev ntsuas kev sib khi tau piav qhia hauv B.4, cov dej xau yuav tsum tsis txhob siab dua ISO 5208 ( 1993) Chav Kawm D. lub sij hawm, tshwj tsis yog hais tias lwm yam. " Nco tseg nyob rau hauv tus qauv: "Cov ntawv thov tshwj xeeb yuav xav tau kev xau tsawg dua ISO 5208 (1993) Class D ¨J." Yog li ntawd, yog tias muaj qhov yuav tsum tau xau siab tshaj tus qauv hauv kev tsim qauv engineering, nws yuav tsum tau muab rau hauv daim ntawv cog lus txiav txim. API 6D--2008 Cov Ntawv Ntxiv B Cov Lus Qhia Ntxiv Ntxiv Kev Xeem qhia meej cov kev xeem ntxiv rau lub valve f J yuav tsum ua los ntawm cov chaw tsim khoom thaum teev los ntawm tus neeg yuav khoom. Kev ntsuas sealing yog muab faib ua qhov ntsuas qis thiab siab-siab gas sealing test. Kev ntsuas kub siab sealing siv cov roj inert raws li qhov ntsuas nruab nrab yuav hloov cov kua-up sealing test thiab cov kua-sealing test. Raws li hom, txoj kab uas hla thiab qib siab ntawm lub valve, kev ntsuas kev sib khi tuaj yeem raug xaiv, thiab cov kev cai ntawm ISO 5208 tus qauv tuaj yeem raug xa mus rau. Rau cov li qub ntawm cov kav dej ntev GL thiab cov kav dej muaj GCl, nws raug nquahu kom siv cov kev ntsuas qis qis, uas tuaj yeem txhim kho cov khoom tsim nyog ntawm lub valve. Thaum xaiv qhov kev ntsuam xyuas siab sealing, nws yuav tsum tau muab sau tseg tias tom qab lub siab-siab sealing xeem ntawm elastic sealing valve, nws sealing kev ua tau zoo nyob rau hauv qis-pressure tej yam kev mob yuav raug txo. Lub valve sealing xeem yuav tsum tau xaiv kom tsim nyog raws li qhov tseeb ua haujlwm ntawm qhov nruab nrab, uas tuaj yeem txo cov nqi tsim khoom ntawm lub valve.
4) American National Standard of the American Instrument Association Standard ANSI/FCI 70-2 (ASME B16.104) muaj feem xyuam rau cov kev cai ntawm qib sealing ntawm lub valve tswj. Engineering tsim yuav tsum tau ua raws li cov yam ntxwv ntawm qhov nruab nrab thiab lub valve
Cov yam ntxwv xws li kev qhib lub qhov rooj yuav tsum xav txog kev xaiv cov hlau elastic foob lossis hlau foob. Cov qib sealing ntawm cov hlau-sealed tswj valve yuav tsum tau teev nyob rau hauv daim ntawv cog lus. Raws li kev paub dhau los, rau cov hlau-sealed tswj li qub, qhov yuav tsum tau ua rau qib I, II, thiab III yog qhov tsawg, thiab lawv siv tsawg dua hauv kev tsim engineering. Feem ntau, cov hlau kaw lub valve feem ntau tsawg kawg yog qib IV, thiab ntau qhov tseem ceeb tswj li qub siv qib V lossis VI. Kev tswj valve tsim ntawm lub teeb hluav taws xob ntawm cov nroj tsuag ethylene txais cov kev cai ntawm cov hlau foob qib IV thiab khiav zoo.
(4) Tsis tas li ntawd, yuav tsum tau them nyiaj mloog mus rau kev tsim qauv engineering: API 6D qhia tias cov ntsiab lus chloride ion ntawm cov dej siv hauv kev sib khi ntawm austenitic stainless hlau li qub yuav tsum tsis pub tshaj 30ug / g, thiab ISO 5208 thiab API 598. qhia tias qhov kev sib khi ntawm austenitic stainless hlau li qub Cov chloride ion cov ntsiab lus ntawm cov dej siv yuav tsum tsis pub tshaj 100ug / g. Vim yog qhov sib txawv ntawm txhua tus qauv, nws tau hais tias cov ntsiab lus ntawm cov tshuaj chloride ion ntawm cov dej siv hauv kev sib khi yuav tsum tau teev meej meej hauv daim ntawv cog lus valve.
4 Kev faib tawm tus qauv ntawm qis to valve sealing qib
Tsawg to valve yog hais txog qhov me me ntawm lub valve, uas tsis tuaj yeem txiav txim siab los ntawm cov pa dej siab thiab kev ntsuas cua siab sealing, thiab yuav tsum tau kuaj xyuas los ntawm cov cuab yeej thiab cov cuab yeej siv siab dua. Qhov no me me ntawm lub valve mus rau qhov chaw sab nraud yog hu ua low to. Tam sim no, cov qauv siv feem ntau txhawm rau txhawm rau txhawm rau qis qis hauv lub ntiaj teb feem ntau suav nrog peb cov hauv qab no:
(1) US Environmental Protection Agency EPA method 21 "Leak Detection of Volatile Organic Cheebtsam".
(2) International Organization for Standardization ISO 15848 (Industrial Valves: Low Leakage Measurement, Testing and Qualification Procedures).
(3) Lub Tuam Txhab Roj Hmab SHELL MESC SPE 77/312 "Industrial Valves: Kev ntsuas qhov tsis tshua muaj dej, Kev faib cov txheej txheem, Cov txheej txheem tsim nyog thiab hom kev pom zoo thiab cov khoom kuaj ntawm On-Off Valves thiab Tswj Valves".
EPA Method 21 tus qauv ntawm US Environmental Protection Agency tsuas yog qhia txog txoj kev tshawb nrhiav yam tsis muaj kev faib cov qib to. Nws yog cov qauv hauv zos thiab kev tswj hwm thiab siv tsawg dua. Ob tus qauv ntawm International Organization for Standardization ISO 15848 thiab SHELL MESC SPE 77/312 ntawm Shell Oil Company ntsuam xyuas qhov kev ua tau zoo ntawm lub valve los ntawm peb yam: qib nruj, qib durability thiab kub. Cov qib nruj yog muab faib ua peb qib: A, B, thiab C rau cov pa tawm ntawm lub valve qia thiab lub valve lub cev foob. Qhov kev xav tau ntawm cov dej xau ntawm ISO 15848 tus qauv valve lub cev foob yog Tsawg dua lossis sib npaug li 50 em3 / m3, thiab cov xau ntawm lub qia valve muaj ob tus qauv. Tag nrho cov yog xam raws li txoj kab uas hla ntawm lub valve qia.
5 Kev xaiv ntawm cov dej xau qis
Bellows-sealed li qub yog ib hom qis-kawg valve. Yav dhau los, lub twj tso kua mis foob valve feem ntau yog siv rau hauv kev ua haujlwm uas muaj cov kev cai tshwj xeeb rau qib to ntawm lub valve. Txawm li cas los xij, vim yog kev ua haujlwm nyuaj thiab kev ua haujlwm siab ntawm lub tshuab nqus tsev twj tso kua mis, cov khoom siv hauv lub tshuab nqus dej tsis tuaj yeem ua tiav hauv zos, thiab tus nqi siab dhau lawm. , yog li txwv nws txoj kev siv dav hauv kev lag luam petrochemical. Tam sim no, nrog rau kev txhim kho txuas ntxiv ntawm tib neeg txoj kev paub txog kev nyab xeeb thiab kev tiv thaiv ib puag ncig, kev nce kev koom tes nrog cov teb chaws txawv teb chaws, thiab kev txhim kho txuas ntxiv ntawm cov tuam txhab tsim hluav taws xob hauv tsev 'tus kheej lub zog, cov neeg ua haujlwm hauv tsev kev nkag siab ntawm cov pa tawm qis kuj tseem muaj. tau txhim kho tsis tu ncua, ua rau nws daim ntawv thov ntau yam nyob rau hauv tas li expanding. Yog hais tias cov valves xaiv rau cov nplaim taws, tawg thiab tshuaj lom hauv kev lag luam petrochemical tuaj yeem ua tau raws li tus qauv xau qis, qhov no yuav ua rau txo qis kev tawm ntawm cov tshuaj lom, flammable thiab explosive media hauv cov cuab yeej, thiab zam qhov hluav taws kub, tawg, lom, thiab lwm yam. los ntawm valve to. Kev huam yuaj tshwm sim. Piv nrog rau lub hauv siab valve, lub valve qis qis uas ua tau raws li ISO15848 thiab SHELL MESC SPE 77/31 tus qauv muaj cov qauv yooj yim dua thiab yooj yim rau kev tsim khoom, thiab nws cov nqi yog kwv yees li 10 feem pua rau 20 feem pua siab dua li cov hom phiaj dav dav. li qub.
6 Kev xaus
Thaum xaiv cov qib sealing thiab qhov kev tso cai tso tawm, nws yuav tsum tau muab sau tseg tias cov pa tawm ntawm qhov nruab nrab ntawm cov sealing nto nyob rau hauv lub siab-siab valve yuav ua rau nto erosion. Yog tias muaj cov pa tawm ntawm qhov nruab nrab corrosive, cov hlau ntawm qhov xau yuav raug corroded. Nrog rau qhov nce ntawm qhov sib txawv ntawm qhov to, qhov to kuj yuav nce sai, thiab lub valve yuav raug muab pov tseg. Yog li ntawd, rau li qub ua hauj lwm nyob rau hauv siab siab los yog corrosive nruab nrab tej yam kev mob, siab dua yuav tsum tau muab tso rau pem hauv ntej nyob rau hauv cov nqe lus ntawm kev ruaj ntseg nruj. Hauv cov kav xa hluav taws xob thauj cov khoom siv hluav taws xob, cov khoom tawg thiab cov tshuaj lom neeg, cov xau ntawm cov xov xwm ntawm lub valve sealing qhov chaw yuav ua rau tus kheej raug mob, kev lag luam poob thiab txawm tias muaj xwm txheej. Yog li ntawd, rau cov li qub uas thauj cov nplaim hluav taws, tawg thiab muaj kuab lom, cov kev sib khi yuav tsum tau muab tso rau pem hauv ntej raws li qhov txaus ntshai ntawm cov xov xwm.
Txhua lub foob tuaj yeem tso cai me me ntawm cov xau, thiab yog tias qhov xau no tsis ua haujlwm, nws tuaj yeem suav tias yog lub foob kaw ntom ntom. Cov txheej txheem kev lag luam valve feem ntau tau teev tseg tias qee qhov kev xa tawm tau tso cai thaum lub foob hlau-rau-hlau raug sim rau kev sib khi ua haujlwm hauv lub xeev kaw. Txhawm rau kom ntseeg tau tias qhov kev sib khi siab ntawm lub valve, lub sealing nto yuav tsum tau ua tib zoo ua tib zoo ua kom lub siab tshwj xeeb ntawm lub sealing nto, tab sis nws tsawg dua qhov tso cai tshwj xeeb ntawm cov khoom siv sealing, thiab tib lub sijhawm, lub rigidity ntawm cov qauv yuav tsum tau txhim kho. Cov kev paub ntawm kev siv lub valve qhia tau hais tias nyob rau hauv ntau rooj plaub, nws yog ib qhov tsim nyog los muab cov kev xav tau siab dhau ntawm kev sib khi ntawm lub valve, vim tias qee qhov kev ua haujlwm tag nrho tso cai rau me me ntawm qhov nruab nrab, vim tias qhov xau no tsis txaus. cuam tshuam rau kev siv lub valve. Hloov pauv, kev txhim kho kev sib khi ntawm cov li qub no ua rau nyuaj rau kev tsim khoom, nce nqi, thiab tsim cov khoom pov tseg tsis tsim nyog. Cov qauv tsim thiab kev tsim khoom ntawm lub valve nws tus kheej muaj qhov pom tseeb tshaj plaws ntawm kev tawm sab nraud. Tsawg-kawg li qub muaj cov kev cai nruj dua ntawm kev tsim, tsim khoom thiab ua cov khoom tseem ceeb xws li lub cev valve, qia valve thiab cov thawv ntim khoom, xws li:
(1) Qhov zoo ntawm lub valve lub cev thiab lub hau npog, tshwj xeeb tshaj yog thaum forging lossis casting, yuav tsum tsis txhob muaj qhov tsis xws luag xws li folding, slag inclusion, pores, cov ntaub so ntswg khiav tawm, zais cov kab nrib pleb thiab tsis sib xws.
(2) Kev ua haujlwm zoo ntawm qhov chaw ntawm kev sib txuas ntawm lub qia valve thiab lub valve lub cev, tshwj xeeb tshaj yog qhov roughness ntawm lub valve qia thiab lub thawv ntim khoom, qhov ncaj ntawm lub valve qia, qhov verticality ntawm lub bonnet stuffing box qhov thiab qhov machining raug.
(3) Cov qauv ntawm lub valve ntim lub thawv yog xaiv. Txij li thaum lub foob ntawm lub qia valve yog lub foob dynamic, cov khoom ntim tau yooj yim hnav thaum lub sijhawm sib hloov lossis zawv zawg ntawm lub qia valve. Qhov tshwj xeeb uas tsis tshua muaj paug packing seals thiab packing seals yuav tsum tau xaiv, thiab cov packing thiab packing yuav tsum nruj me ntsis tswj. Nroj tsuag clearance, packing thiab stuffing box clearance.
Hauv cov ntsiab lus, kev xaiv cov hom valve yuav tsum tsis yog tsuas yog ua tau raws li cov txheej txheem thiab cov qauv tshwj xeeb, tab sis kuj xav txog ntau yam kev ua haujlwm. Hauv kev tsim qauv engineering, qib valve sealing yuav tsum raug xaiv kom ua tau raws li cov hauv paus ntsiab lus ntawm kev nyab xeeb, kev tsim nyog thiab kev lag luam.