Stainless Hlau Al-6xN Tube Asme Sb 676 Tsis Ua N08367 Tubing

Stainless hlau 316 yog Austenitic stepless stortless nrog 4% molybdenum nyob rau hauv nws muaj pes tsawg leeg. Cov ntsiab lus ntawm chromium, npib tsib xee thiab molybdenum ua rau stainless hlau 316 muaj zog dua, corrosion resistant thiab ductile.

S31803 yog cov qauv sau ua ke (tsis ua haujlwm) rau thawj lub duplex stainless hlau stainless. Cov txheej txheem tsis zoo tau tsim los ntawm cov pab pawg ua lag luam hauv xyoo 1970 los txo kev tsis meej pem thaum tib almoy tau hu ua ntau yam sib txawv, thiab hloov ua lwm yam. Txhua tus hlau yog sawv cev los ntawm ib tsab ntawv ua raws li tsib tus lej, qhov twg tsab ntawv sawv cev ntawm cov hlau series, i.E. s rau stainless hlau.

? Tus? ASTM A182 F304 flanges? Yuav ntxuav tau yooj yim nrog ib qho tshuaj ntxuav me me. Txawm hais tias tau rov qab ua dua cov txheej txheem tu, cov flanges yeej¡-kawg, muaj peev xwm nws cov khoom pov thawj vim nws tau hnav cov khoom tiv thaiv nws. Ntxiv mus, txij li qib 304 yog ib qho alloy uas tuaj yeem tsim tau yooj yim rau hauv ib hom duab, nws yog qhov yooj yim shau rau hauv ib qho ntawm as44 yeeb nkab flange lossis ib qho? INOX 304 NPE rau Flange.

Ib txoj kev sib koom ua ke flanged yog tsim ntawm peb cais thiab ywj siab yog tias muaj kev sib cuam tshuam; Cov flanges, lub gaskets, thiab cov bolting; Uas tau sib sau los ntawm kev cuam tshuam lwm tus cuam tshuam, fitter. Cov kev tswj tshwj xeeb yuav tsum muaj nyob rau hauv kev xaiv thiab kev xaiv ntawm tag nrho cov muaj cov ntsiab lus kom muaj kev sib koom ua ke, uas tau siv tau xau nruj.

ASME B36.19M yog tus qauv kev qhia tshwj xeeb rau cov kav hlau stainless hlau, uas qhia txog kev ua siab ntev, thiab tsim khoom rau cov kav dej thiab cov txiv ntseej.

ASTM A182 Stainless Hlau 309 Flanges Tus Neeg Muab Khoom Siv, Excange, Ansi B16.47 SS 309 Sorf Flanges, Stainless Hlau WNR. 1.4828 flanges nyob hauv Suav teb.

Al6XN yog superaustenitic steel hlau nrog kev ua tau zoo rau chloride pitting, crevice corrosion thiab kev nyuaj siab corrosion tawg. Al6XN yog 6 Moly alloy uas tau tsim rau thiab siv hauv kev sib cav sib ceg siab. Nws muaj cov npib tsib xee (24%), Molybdenum (6.3%), nitriumen thiab chromium cov ntsiab lus tawg, thiab tshwj xeeb corrosion tiv thaiv. Al6XN yog feem ntau siv rau nws cov kev txhim kho pitting thiab crevice corrosion tsis kam hauv chlorides. Nws yog ib qho tsim nyog thiab weldable stainless hlau.

Austenitic stainless hlau ntawm 304 thiab 304L yog qhov ntau tshaj plaws thiab ntau siv cov hlau tsis huv. Lawv nthuav tawm cov kev tiv thaiv corrosion zoo heev nyob rau hauv ntau qhov kev xeb ib puag ncig. Qeb 304 thiab 304l stainless hlau cov kav hlau nthuav tawm zoo machinability thiab zoo heev weldability nrog los yog tsis muaj tub lim hlau ntxiv.

Ib Flange yog ib qho kev tawm tsam, daim di ncauj lossis sab nraud, tog twg los sab nraud lossis sab hauv, uas yog cov nqaj hlau xws li ib tug t-nqaj); Rau cov ntawv yooj yim tau yooj yim \ / hloov ntawm kev sib cuag nrog lwm yam khoom (raws li flange thaum kawg ntawm cov yeeb nkab, chav dej lub tog raj kheej, lossis ntawm lub ntsej muag lub koob yees duab); Los yog rau kev ruaj khov thiab taw qhia kev txav ntawm lub tshuab lossis nws cov ntu (raws li sab hauv flange ntawm tsheb ciav hlau lossis lub log los ntawm kev khiav tawm ntawm cov ciav hlau). Lo lus "Flange" kuj yog siv rau hom cuab yeej siv los ua cov flanges.

Tshuab ua haujlwm zoo ib yam li cov khoom siv hardened tsis zoo thiab nws yog ib qho kev ua haujlwm hnyav thiab muaj cov cuab yeej tsis zoo, cov cuab yeej hnyav thiab cov khoom siv ntse. Siv cov tshuab haib thiab hnyav nruj cov cuab yeej.

Lub ntsiab Cheebtsam ntawm 304 stainless hlau¡ªide Los ntawm Hlau¡ªare Chromium thiab Nickel. 304 muaj 18 - 20% chromium (CR). Chromium yog ib qho tseem ceeb rau txhua tus hlau, nws tsim cov txheej uas passivation nyias uas ua rau cov hlau "stainless"

316 Stainless hlau yog ntau yam; Nws tsis tsuas yog muaj zog ua kev sib haum thiab muaj peev xwm muaj lub peev xwm khawm lossis crimp, yog li nws tuaj yeem hloov tau yooj yim rau ntau cov ntawv thov.

Lub Flange yog qhov thib ob feem ntau siv koom nrog txoj kev tom qab selding. Kev siv flanges tau siv thaum cov pob qij txha xav tau dismantling. Nws muab kev hloov tau rau kev saib xyuas. Flange txuas cov yeeb nkab nrog ntau yam khoom siv thiab li qub. Breakup Flanges tau ntxiv rau hauv cov raj xa hluav taws yog tias kev saib xyuas tsis tu ncua thaum lub sijhawm cog ntoo.

309 stainless hlau yog ib hom ntawm cov hlau tsis muaj tshuaj tiv thaiv stainless hlau uas feem ntau siv nyob rau hauv cov ntawv thov kub siab vim nws cov kub ua kom zoo. Sa240 309 lub phaj muaj qhov feem pua ​​siab ntawm chromium thiab npib tsib xee, uas muab nws zoo li qib siab ntawm lub zog thiab kav ntev. SS 309 SAWB (UNR UNST S30900) yog Austenitic Stainless hlau tsim rau kev siv nyob rau hauv cov kev siv kub siab tiv thaiv kev siv. Lub sa240 309 phaj tiv thaiv oxidation txog 1900 ° F (1038 ° C) nyob rau hauv uas tsis tshaj plaws. Nquag thermal cycling txo oxidation tsis kam kwv yees li 1850 ° F (1010 ° C).

304 Piping spools yog tsim los ntawm 304 stainless hlau, ib qho khoom siv nrov thiab nrov tshaj plaws hauv ntau cov ntawv thov uas xav tau kev tiv thaiv kom xeb thiab oxidation. Cov kev tshaj lij no yog preooss siv cov machinery thiab cov txheej txheem tshwj xeeb, uas paub meej tias lawv muaj tseeb thiab ntseeg tau.

ASME B16.47 Series A muaj nyob rau hauv cov chav kawm 150, 300, 400, 600, 900; uas ntawm asme B16.47 koob b muaj nyob rau hauv cov chav kawm 75, 150, 300, 400, 600, 900, 900, 900

Stainless hlau 316Ti hex taub hau rau hauv cov cheeb tsam uas tuaj yeem tiv taus ntau dua hom 304, thiab lawv cov pa roj carbon ntau dua li cov tshuaj nag. Txawm li cas los xij, zoo li ntau cov hlau uas tsis muaj hlau, stainless hlau 316Ti hex taub hau muaj peev xwm sov chlorine ib puag ncig thiab tuaj yeem tsim cov pits thiab tawg.
304 Stainless hlau yog ib qeb ntawm stainless hlau tsim raws li cov neeg Asmeskas cov roj uas tsis muaj 3040 lossis muaj peev xwm muab tshuaj kom zoo tshaj li 3040 lossis cov pa roj cua sov ntau tshaj li 3040
Hmoov tsis zoo li S32100 thiab qib 32% rau 19% rau 1 xee, .70% titanium, nrog qhov sib npaug yog hlau. Nrog rau kev cuam tshuam rau corrosion tsis kam, 321 stainless hlau yog sib npaug rau qib 304 nyob rau hauv anealed mob thiab zoo dua yog tias daim ntawv thov cuam tshuam nrog 797¡Ã li 1652¡Ã f ntau. 321 Stainless hlau ua ke siab lub zog, tiv taus rau scring thiab theem kev ruaj khov nrog kev tiv thaiv a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a axoous.

ASTM A276 304 Stainless Hlau Round tuav tau tsim los ntawm cov hlau zoo stainless thiab muaj cov tshuaj tiv thaiv corrosion. Cov qib qib ntawm cov hlau no tau siv dav hauv cov ntawv thov uas muaj zog, zoo heev corrosion tsis kam, thiab yuav tsum muaj Weldability zoo. Lub AISI 304 stainless hlau puag ncig yog ib qho ntawm feem ntau ntau yam thiab dav siv hom hlau stainless. ASTM A276 304 Stainless Hlau Round bar tseem muaj lub npe hu ua 18 \ / 8 stainless hlau vim tias nws muaj 18% chromium thiab 8% npib tsib xee.
Thickness: Sch5 ~ Schxxs
Myanmar (Burmese)
Haitian croole
Forged flanges
DupleX Steel Flanges
Stainless hlau kav Khoom siv hlau 316
Cov Khoom Siv Neeg Kho Tshuab Ntawm Cov Hlau Stainless 309 Flanges
Stainless Hlau 309 Flanges
Zhengzhou Huitong Pipeline Equipment Co., Ltd.
Kev lag luam lossis rau cov teeb meem ntawd kev lag luam uas nyob ntawm kev siv rau Machineries.
Stainless Hlau Daim Hlau & Cov Ntawv Qhia & Coils

316L 1.4401 tus yeeb nkab stainless hlau yog ib qho kev xaiv yeeb nkab zoo heev thiab cov yeeb nkab ruaj khov siv hauv ntau cov ntawv siv. Qhov no ss s31603 yeeb nkab yog tsim los ntawm cov hlau zoo 316L stainless ua rau corrosion, oxidation thiab staining rau cov chaw hnyav lossis kev siv ntxhov siab.
316 310s Stainless Hlau Yeeb
Myanmar (Burmese)
Haitian croole
Forged flanges
DupleX Steel Flanges
Stainless hlau kav Khoom siv hlau 316
ASTM A213 Stainless Hlau 904L Tubes Tus Neeg Siv Khoom Noj 1.4539 Tubes
Stainless Hlau 309 Flanges
Zhengzhou Huitong Pipeline Equipment Co., Ltd.

Qeb 309 flanges tuaj yeem ua kom muaj huab cua sov heev, huab cua tsis zoo, thiab cov chloride ib puag ncig. Cov ntaub ntawv no yog lub npe ntawm ib tsev neeg ntawm cov corrosion-resistant steels, tsis yog ib yam khoom xwb. Nyob ntawm cov muaj peev xwm ntau yam, muaj ntau yam dav dav ntawm stainless hlau 309 flanges muaj nyob rau hauv nyias diameters, phab ntsa thicknesses, thiab ntau ntau ntawm kev ntsuas. Txij li SS 309 flanges tuaj yeem txhawb nqa ntawm 1038 degrees Celsius ua ntej tau tua tawm hauv dej, astm A182 F 309s flanges kuj tiv thaiv lub nkoj marine. Lub stainless hlau 309 xov uas tsim nyog ntawm lub neej niaj hnub thiab tau siv cov ntawv thov kev ua haujlwm, xws li cov khoom siv hluav taws xob, thiab cov khoom siv thiab tshuab thiab tshuab thiab tshuab thiab tshuab. Vim tias lawv lub zog tensile, kev ua phem rau kev ua haujlwm, thiab yooj yim ntawm kev txij nkawm, cov khoom siv stainless hlau yog cov khoom zoo rau ntau yam kev siv. Tsis tas li ntawd, stainless hlau 309 forged flange yog 100% siv dua tshiab thiab muaj lub voj voog ntev.

SS 316 \ / 316L Flanges yog ib qho ntawm feem ntau nrhiav tau tom qab cov khoom hauv kev lag luam. Cov flanges no tau paub rau lawv cov khoom xws li corrosion zoo dua, pitting thiab crevice corrosion thaum piv rau hom 304.
Thickness: Sch5 ~ Schxxs
Myanmar (Burmese)
Haitian croole
Forged flanges
DupleX Steel Flanges
Stainless hlau kav Khoom siv hlau 316
Cov Khoom Siv Neeg Kho Tshuab Ntawm Cov Hlau Stainless 309 Flanges
Stainless Hlau 309 Flanges
Zhengzhou Huitong Pipeline Equipment Co., Ltd.
Kev lag luam lossis rau cov teeb meem ntawd kev lag luam uas nyob ntawm kev siv rau Machineries.
Stainless hlau hexagonal tuav hauv ntev ntev

Stainless hlau 321 \ / 321H cov yeeb nkab fittings yog siv hauv kev lim, tub yees, roj, petrochemical thiab hauv offshoden roj tho kev lag luam. Cov khoom siv chromium, npib tsib xee, titanium thiab lwm cov khoom raws nrog cov pa roj carbon. Lub 321h muaj ntau dua cov pa roj carbon monoxide dua li lwm cov versions. Nws muaj ntau hom fittings xws li cov 321 \ / 321h stainless hlau bollowd fittings uas feem ntau siv tab sis kuj muaj cov fittings. Lub stainless hlau uns s32100 yeeb nkab luj yog hom phim yog siv rau hauv cov ntawv thov kub kom hloov cov kev taw qhia ntawm kev ntws.

309 stainless hlau yog ib hom ntawm cov hlau tsis muaj tshuaj tiv thaiv stainless hlau uas feem ntau siv nyob rau hauv cov ntawv thov kub siab vim nws cov kub ua kom zoo. Sa240 309 lub phaj muaj qhov feem pua ​​siab ntawm chromium thiab npib tsib xee, uas muab nws zoo li qib siab ntawm lub zog thiab kav ntev. SS 309 SAWB (UNR UNST S30900) yog Austenitic Stainless hlau tsim rau kev siv nyob rau hauv cov kev siv kub siab tiv thaiv kev siv. Lub sa240 309 phaj tiv thaiv oxidation txog 1900 ° F (1038 ° C) nyob rau hauv uas tsis tshaj plaws. Nquag thermal cycling txo oxidation tsis kam kwv yees li 1850 ° F (1010 ° C).

304 Stainless hlau, tseem hu ua 18 \ / 8, yog ib hom ntawm chromium-npib tsib xee stainless hlau nrog cov khoom siv muaj zog thiab dav. Raws li ib tug dav hlau siv, nws muaj cov zoo corrosion tsis kam, kub tsis kam, lub zog thiab tsis muaj kub tshuab hluav taws xob. Cov kev ua haujlwm kub kub tau zoo xws li Stamping thiab khoov. Tsis muaj cua sov kho cua sov dab tsi. Yog tias nws nyob hauv thaj chaw muaj kuab paug, nws yuav tsum tau ntxuav kom huv rau lub sijhawm kom tsis txhob xeb.
Thickness: Sch5 ~ Schxxs
Myanmar (Burmese)
Haitian croole
Forged flanges
DupleX Steel Flanges
Stainless hlau kav Khoom siv hlau 316
Cov Khoom Siv Neeg Kho Tshuab Ntawm Cov Hlau Stainless 309 Flanges
Stainless Hlau 309 Flanges
Zhengzhou Huitong Pipeline Equipment Co., Ltd.
Kev lag luam lossis rau cov teeb meem ntawd kev lag luam uas nyob ntawm kev siv rau Machineries.
Orifice Flange Asme B16.36 S31603 1.440 Flange

Stainless hlau 316 Yeeb yog ib qho tshuaj ntsuab stainless hlau qib yeeb nkab cov yeeb nkab uas muaj kev tsis zoo rau chloside ion corrosion kev ntxhov siab tawg. Vim li no, cov yeeb nkab siv rau hauv cov khoom siv marine thiab dej hiav txwv dej hiav txwv uas yooj yim.
Thickness: Sch5 ~ Schxxs
Myanmar (Burmese)
Haitian croole
Forged flanges
DupleX Steel Flanges
Stainless hlau kav Khoom siv hlau 316
Cov Khoom Siv Neeg Kho Tshuab Ntawm Cov Hlau Stainless 309 Flanges
Stainless Hlau 309 Flanges
Zhengzhou Huitong Pipeline Equipment Co., Ltd.
Kev lag luam lossis rau cov teeb meem ntawd kev lag luam uas nyob ntawm kev siv rau Machineries.
Loj od: 1 \ / 2 "" ~ 48 ""

Ib lub flange yog lub nplhaib ntawm cov hlau (forged, txiav los ntawm phaj, lossis koom nrog cov yeeb nkab ntawm cov yeeb nkab, lossis los koom nrog cov hlab ntsha, lossis mus ua ke lossis lwm qhov chaw sib dhos. Flanges tau koom nrog txhua lwm yam los ntawm kev siv pas dej los ntawm vuam los yog xov (lossis xoob thaum cov quav xaus yog siv). Stainless hlau Flange Tau yooj yim raws li ss flange, nws yog hais txog cov flanges uas ua los ntawm stainless hlau. Cov qauv qauv ib txwm muaj thiab qib AN182% F304 \ / L thiab / L thiab / / /50.

ASTM A312 TP316 yog tus qauv txheem rau kev sib khi, ncaj-leeg welded, thiab hnyav txias welded ustenitic kav hlau stainless hlau thiab kev corrosive service. Lub 316 seamless muaj steel yeeb nkab yog tsim los ntawm kev sib xyaw ntawm cov chromium, npib tsib, thiab molybdenum ua rau corrosion thiab xeb thiab xeb thiab xeb thiab xeb.

Kuj tseem muaj cov qauv sib txawv uas tswj hwm cov nominal qhov ntau thiab tsawg ntawm cov flanges. Ansi B16.5 SS 309s Qhov muag tsis pom Flange yog qhov muag tsis pom flange uas tau siv los kaw kev sib txuas.

Stainless hlau 316Ti hex taub hau rau hauv cov cheeb tsam uas tuaj yeem tiv taus ntau dua hom 304, thiab lawv cov pa roj carbon ntau dua li cov tshuaj nag. Txawm li cas los xij, zoo li ntau cov hlau uas tsis muaj hlau, stainless hlau 316Ti hex taub hau muaj peev xwm sov chlorine ib puag ncig thiab tuaj yeem tsim cov pits thiab tawg.
304 Stainless hlau yog ib qeb ntawm stainless hlau tsim raws li cov neeg Asmeskas cov roj uas tsis muaj 3040 lossis muaj peev xwm muab tshuaj kom zoo tshaj li 3040 lossis cov pa roj cua sov ntau tshaj li 3040
Hmoov tsis zoo li S32100 thiab qib 32% rau 19% rau 1 xee, .70% titanium, nrog qhov sib npaug yog hlau. Nrog rau kev cuam tshuam rau corrosion tsis kam, 321 stainless hlau yog sib npaug rau qib 304 nyob rau hauv anealed mob thiab zoo dua yog tias daim ntawv thov cuam tshuam nrog 797¡Ã li 1652¡Ã f ntau. 321 Stainless hlau ua ke siab lub zog, tiv taus rau scring thiab theem kev ruaj khov nrog kev tiv thaiv a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a axoous.

316 316L Cov Kav Dej ...
Lub unr unic s31803 (ASTM F51) Cov lus qhia tshwj xeeb tau ua rau muaj ntau dua Superseded los ntawm Unvent S32205 (1.4462, ASTM F60). Qhov no qhia txog lawv txoj kev xav kom ua kom tiav ntawm cov khoom siv alloy, ua tsaug rau kev txhim kho AOD cov txheej txheem ntawm kev tswj hwm. Ib qho ntxiv, nws tso cai rau cuam tshuam rau cov nitrogen ntxiv qib ntxiv dua li yog tam sim no yog nyob tom qab keeb kwm. Yog li ntawd, qhov siab tshaj plaws ua tiav cov qib hloov kho kom ua kom ntau cov ntsiab lus ntawm chromium (CR), Molybdenum (mo) thiab nitrogen (n).

Nyob rau hauv cov ntawv thov loj heev, chromium thiab npib tsib xee hom stainless hlau yog siv vim tias lawv cov cua sov thiab xeb-tsis kam. Pom nyob rau hauv cov ntawv thov uas yuav tsum muaj siab dua, stainless hlau dav hlau tubing tuaj yeem ua haujlwm lossis welded, zoo li ua haujlwm tau siv nrog qee hom tshuaj xeb. Cov roj carbon tsawg ntawm cov hlau stainless yog ib qho kev xaiv rau welded seem.

Rau cov ntawv sau zeb hauv av uas xav tau cov qib qis dua uas tsis muaj cov xeb txaus tiv thaiv. Raws li 22% chromium cov ntsiab lus, lawv muaj cov ustenitic: Ferritic microstructure uas muaj zog dua, corrosion tsis kam thiab nqi-ua hauj lwm zoo.

Lub stainless hlau 304 yeeb nkab fittings kuj muaj zog. Lawv muaj 205MPA yam tsawg kawg ntawm lub zog muaj zog thiab 515MPA yam tsawg kawg tensile lub zog.

Ib Flange yog ib qho kev tawm tsam, daim di ncauj lossis sab nraud, tog twg los sab nraud lossis sab hauv, uas yog cov nqaj hlau xws li ib tug t-nqaj); Rau cov ntawv yooj yim tau yooj yim \ / hloov ntawm kev sib cuag nrog lwm yam khoom (raws li flange thaum kawg ntawm cov yeeb nkab, chav dej lub tog raj kheej, lossis ntawm lub ntsej muag lub koob yees duab); Los yog rau kev ruaj khov thiab taw qhia kev txav ntawm lub tshuab lossis nws cov ntu (raws li sab hauv flange ntawm tsheb ciav hlau lossis lub log los ntawm kev khiav tawm ntawm cov ciav hlau). Lo lus "Flange" kuj yog siv rau hom cuab yeej siv los ua cov flanges.

Tsis suav txog N08367 tseem hu ua Alloy Al6XN yog cov carbon ntau, siab purity, nitrogen-batoy nrog zoo heev rau chloride pitting thiab compevice corrosion.

304 Stainless hlau tau ua tau zoo heev rau ntau yam ntawm cov cheeb tsam cheeb tsam thiab ntau cov xov xwm corrosive. Nws yuav tau kev pitting thiab crevice corrosion nyob rau hauv sov chloride ib puag ncig, thiab kev nyuaj siab corrosion cracking saum toj saud txog 60 Ã Ã Ã Ã Ã Ã Ã Ã. Nws suav hais tias yog tiv taus rau pitting corrosion nyob rau hauv dej txog li 400 mg \ / l chloride ntawm huab cua kub, tsawg dua li ntawm 150 mg

Xws li lub taub qab weld haum, nws ua haujlwm nrog kua mis flanges. Kev siv ntawm stainless hlau luv qauv yeeb nkab xaus thiab kua ntsa flanges tuaj yeem txo qis cov nqi txij nkawm. Hauv cov kav dej hlau stainless hlau lossis qib siab, peb tuaj yeem xaiv cov yeeb nkab Lowerless cov khoom siv hloov chaw ntawm cov menyuam welded, ua rau muaj cov nqi tsim khoom lag luam.

310 \ / 310s Stainless hlau yeeb nkab muaj oxidation zoo tsis kam siv nyob rau hauv huab cua txog li 1035¡Ãc thiab kev siv txuas ntxiv ntawm 1050¡Ãcin. Cov qhab nia yog tiv thaiv oxidation, vulcanization thiab carburization.

Lub 316 cov yeeb nkab stainless hlau tau dhau los ua cov khoom siv tsis tau rau cov kev lag luam lag luam. Qhov no alloy ntawm hlau thiab chrome tau lees paub rau nws lub siab tiv taus corrosion, nrog rau nws cov kav ntev. 316 Stainless hlau Tubing tuaj yeem tsim nyob rau hauv ob leeg seamless thiab welded leeg kom tau raws li cov neeg siv khoom xav tau.