Lub luj tshib, Tee, Reducer, Cap: Pipe Fitting Hom Piav Qhia

Cov yeeb nkab fittings yog cov pob txha ntawm txhua qhov dej - tuav qhov system. Txawm hais tias koj yog engineering petrochemical refinery, dej tshuaj-rau-txoj voj, lub chaw ua haujlwm ntawm ntug dej hiav txwv, lossis lub siab - qhov kub thiab txias, cov yeeb nkab fittings ua peb txoj haujlwm tseem ceeb: lawv hloov cov kev taw qhia ntawm ntws, ceg ntws mus rau ntau txoj hauv kev, txuas cov kav dej sib txawv, thiab txiav los yog foob cov kav dej.

Qhov tshwm sim ntawm kev xaiv tsis raug haum yog qhov hnyav. Ib tug haum ntawm qhov tsis ncaj ncees lawm kev ntsuas yuav rupture nyob rau hauv ib txwm ua hauj lwm tej yam kev mob. Ib qho khoom haum uas tsim los ntawm cov khoom siv tsis sib xws tuaj yeem corrode, paug cov txheej txheem dej, lossis ua rau muaj kev puas tsuaj loj hauv lub hlis ntawm kev ua haujlwm. Ib qho haum ua rau qhov tsis ncaj ncees lawm tus qauv tsim kev sib dhos npau suav phem, weld tsis xws luag, thiab raug nqi ntau dua.

Elbow Tee Reducer Cap Types

Cov kab lus no tau tsim los ua cov ntaub ntawv qhia tseeb. Nws npog txhua hom yeeb nkab loj haum - lub luj tshib, tees, reducers, caps, couplings, unions, crosses, thiab laterals - nrog cov txheej txheem txhais, seem qauv, cov khoom qib, kev ntsuas siab, thiab kev taw qhia kev xaiv, tag nrho cov kev txhawb nqa los ntawm lub hom phiaj cov ntaub ntawv nrog cov ntaub ntawv qhia meej. Lub hom phiaj yog ib qho kev pabcuam uas muaj txiaj ntsig zoo rau ib tus kws tshaj lij piping uas qhia txog ASME B31.3 txheej txheem piping thiab nkag mus rau cov tub ntxhais kawm ntsib cov yeeb nkab fittings thawj zaug.

Txhua cov yeeb nkab fitting specification pib nrog cov qauv. Cov qauv qhia txog geometry, qhov ntev, kam rau ua, cov khoom yuav tsum tau muaj, siab - qhov ntsuas kub, thiab cov cim cim. Kev qhia kom haum 'rau tus qauv' tsis yog bureaucracy - nws yog lub tshuab uas lub hom phiaj engineering tau ntseeg tau muab txhais ua cov khoom tsim.

Table 1: Thawj Cov Qauv Thoob Ntiaj Teb rau Cov Yeeb Nkab Fittings

Txuj	Muab Lub Cev	Scope thiab Daim Ntawv Thov
ASME B16.9	ASME	Factory-ua pob tw- vuam fittings (lub luj tshib, tees, reducers, caps, crosses). Qhov ntau thiab tsawg NPS 1/2 txog 48. Tus qauv siv dav tshaj plaws thoob ntiaj teb rau cov txheej txheem piping taub qab -weld fittings.
ASME B16.11	ASME	Forged fittings - qhov (socket)- vuam thiab threaded (lub luj tshib, tees, couplings, caps, crosses). Qhov ntau thiab tsawg NPS 1/8 txog 4. Rau me me - tho, siab - cov ntawv thov siab.
Qauv TSIS MUAJ: SP-43	MSS	Wrought stainless hlau taub qab- vuam fittings (lub teeb-phab ntsa, teem caij 5S thiab 10S). Ntxiv ASME B16.9 rau nyias- phab ntsa stainless siv nyob rau hauv cov chaw muag tshuaj, khoom noj khoom haus, thiab qis- kev pabcuam siab.
TSW SP-97	MSS	Integrally reinforced socket weld, threaded, thiab taub qab -weld ceg qhov hluav taws xob fittings (o-cia: weldolet, socket, threadolet). Txhais cov duab geometry rau cov ceg khov kho fittings.
TS EN 10253-4	CEN	Butt-welding yeeb nkab fittings - Ntu 4: Wrought austenitic thiab austenitic-ferritic (duplex) stainless hlau. European tus qauv sib npaug rau ASME B16.9 rau stainless. Dimensions ua raws li EN 10216-5 yeeb nkab.
ASME B16.28	ASME	Wrought steel taub qab- vuam luv luv lub luj tshib thiab rov qab. Npog luv -radius (SR) lub luj tshib geometry qhov chaw muaj kev txwv.
ASME B16.49	ASME	Factory-ua wrought steel taub qab- vuam induction khoov rau kev thauj mus los thiab kev faib khoom. Rau teb-ntsia loj- txoj kab uas hla khoov.
ASTM A403 Cov khoom lag luam	ASTM	Specification rau wrought austenitic stainless hlau piping fittings. Txhais cov tshuaj muaj pes tsawg leeg, cov khoom siv kho tshuab, thiab cov kev xeem yuav tsum tau ua rau austenitic SS taub qab -weld fittings (304, 316, 321, 347, thiab lwm yam).
ASTM A815 Cov Lus Qhia Tshwj Xeeb	ASTM	Specification rau wrought ferritic, ferritic / austenitic, thiab martensitic stainless hlau kav fittings. Npog duplex (2205, 2507) thiab qib ferritic.
ASTM B 366 Cov khoom siv	ASTM	Specification rau Hoobkas- ua wrought nickel thiab nickel alloy fittings. Npog Alloy 625, C-276, 825, 400 thiab lwm yam nickel alloy fittings.

Tau qhov twg los: ASME B16.9-2018, ASME B16.11-2016, MSS SP-43-2008, MSS SP-97-2012, EN 10253-4: 2008, ASTM A403/A403M-22, ASTM A815-2015/A

Ibluj tshibyog cov yeeb nkab haum uas hloov cov kev taw qhia ntawm kev khiav hauv cov kav dej. Nws yog qhov feem ntau siv haum nyob rau hauv tej piping layout. Lub luj tshib tau teev tseg los ntawm lawv lub kaum sab xis, lawv lub vojvoog (ntev lossis luv), lawv qhov loj (NPS), thiab lawv qhov kawg kev sib txuas hom (lub taub qab vuam, lub qhov (socket weld, lossis threaded). Nkag siab txog qhov sib txawv ntawm lub vojvoog yog qhov tseem ceeb rau kev tsim hydraulic.

Steel Elbow Fittings

Ntev Radius vs. Luv Radius Luj tshib

Lub vojvoog ntawm lub luj tshib txiav txim siab sai npaum li cas nws hloov cov kev taw qhia ntws, thiab yog li ntawd ntau npaum li cas lub siab poob nws tsim thiab ntau qhov chaw nws siv. Ob hom kab hluav taws xob tus qauv yog txhais los ntawm lawv qhov nruab nrab lub vojvoog txheeb ze rau cov yeeb nkab nominal loj:

Ntev Radius (LR) Luj Tshib:Centerline vojvoog=1.5 × NPS. Tsim ib tug maj mam hloov nyob rau hauv cov kev taw qhia ntws. Kev txo qis qis, txo qis kev kub ntxhov, thiab kev yaig tsawg dua ntawm qhov khoov. Txaus siab rau feem ntau cov txheej txheem piping applications. Qhia rau ASME B16.9.

Luv Radius (SR) Luj Tshib:Centerline vojvoog=1.0 × NPS. Ntau compact, tab sis tsim ntau dua turbulence thiab siab poob. Siv tsuas yog qhov chaw txwv tsis pub tshaj. Qhia rau ASME B16.28.

Table 2: Ntev Radius vs. Luv Radius Luj tshib - Qhov tseem ceeb Dimensional thiab Performance Comparison

Parameter	Ntev Radius (LR) Luj Tshib	Luv Radius (SR) Luj Tshib
Kev tswj hwm tus qauv	ASME B16.9 (lub taub qab vuam); ASME B16.11 (SW / xov)	ASME B16.28 (ntsuas taub qab vuam)
Centerline vojvoog	1.5 × NPS (eg, 6 "rau NPS 4")	1.0 × NPS (eg, 4 "rau NPS 4")
Siab poob vs. ncaj yeeb nkab (ASME B16.9 hauv paus, NPS 4, dej ntawm 3 m / s)	~ 6 × sib npaug cov yeeb nkab ntev	~ 12 × sib npaug cov yeeb nkab ntev
Erosion/turbulence risk	qis dua - gradual velocity vector hloov	Siab dua - hloov pauv sai, theem nrab ntws
Qhov chaw xav tau	Ntau dua - xav tau lub hnab ntawv loj dua	Compact - nyiam nyob rau hauv congested racks
Cov ntawv thov nyiam	Cov txheej txheem piping, tshuaj, khoom noj, tshuaj, roj & roj, feem ntau ASME B31.3 systems	Cov kav dej siv hluav taws xob, thaj chaw congested, cua sov exchangers, rov khoov rau hauv qhov chaw tsawg
Tus nqi txheeb ze	Txheem - yooj yim muaj nyob rau hauv txhua qib	Tus nqi qis dua; tsawg cov khoom muag ntau yam
NPS ntau yam (ASME)	NPS 1/2 txog 48 (B16.9)	NPS 1/2 txog 24 (B16.28)

Tau qhov twg los: ASME B16.9-2018, Table 1 (dimensional data); ASME B16.28-2018; Crane Technical Paper 410 (siab poob sib npaug ntev).

Lub luj tshib yog tsim los ntawm tus qauv khoov kaum. Peb feem ntau yog:

90℃luj tshib:Lub workhorse ntawm piping systems. Hloov cov kev taw qhia ntws los ntawm 90 degrees. Txog tam sim no feem ntau teev lub luj tshib.

45℃luj tshib:Hloov cov kev taw qhia ntws los ntawm 45 degrees. Siv qhov twg routing yuav tsum muaj kev hloov maj mam hloov. Lub siab poob qis dua 90 degree.

180℃Rov qab (U-khoov):Reverses ntws kev taw qhia kiag li. Siv nyob rau hauv tshav kub exchanger manifolds, coil systems, thiab nyob qhov twg ntws yuav tsum muab ob npaug rau rov qab nyob rau hauv ib tug compact qhov chaw.

Cov ntsiab lus tseeb - Kev xaiv lub luj tshib:

Rau tag nrho cov txheej txheem piping daim ntawv thov raug rau ASME B31.3 lossis B31.1, qhia lub vojvoog ntev 90-degree lub luj tshib rau ASME B16.9 raws li lub neej ntawd. Lub luj tshib luv luv yuav tsum tau teev tseg tsuas yog thaum qhov chaw txwv tau sau tseg thiab pom zoo, thiab txwv tsis pub hauv cov kev pabcuam uas muaj cov slurries erosive, cov pa hluav taws xob siab, lossis cov kav dej piggable qhov twg qhov yuav tsum tau muaj tsawg kawg yog khoov vojvoog.

A teeyog T- zoo li cov yeeb nkab haum uas tso cai rau ntws los ntawm kev sib faib los yog ua ke rau hauv ib lub yeeb nkab. Tees tau teev tseg los ntawm qhov loj ntawm kev khiav (ntawm - txoj kab yeeb nkab) thiab qhov luaj li cas ntawm ceg qhov hluav taws xob. Muaj ob yam tseem ceeb:

Tee Fittings

Equal (Nqe) Tee:Tag nrho peb qhov hluav taws xob yog tib lub nominal yeeb nkab loj. Siv thaum ceg khiav txoj kev yuav tsum nqa tib lub peev xwm raws li kev khiav. NPS A × NPS A × NPS A.

Txo Tee:Lub qhov hluav taws xob yog me dua qhov khiav. Siv thaum ceg ua haujlwm me me ntawm txoj kev - hom kev siv ntau tshaj plaws hauv cov kav dej. Denoted as NPS A × NPS A × NPS B (qhov twg B< A).

Table 3: Tee Fitting Comparison - Equal Tee vs. Txo Tee vs. Branch Connection Alternatives

Parameter	Equal Tee	Txo Tee	Weldolet / ceg qhov hluav taws xob haum (MSS SP-97)
Txuj	ASME B16.9 / EN 10253-4	ASME B16.9 / EN 10253-4	MSS SP-97 (weldolet, qhov (socket), threadolet)
Ceg -rau- khiav piv	1: 1 (qhov sib npaug nkaus xwb)	Txog li 1: 4 txo hauv ceg	Mus txog 1: 8 lossis ntau dua; hloov tau
Kev ntsuas siab	Tag nrho cov yeeb nkab teem caij ntsuas rau ASME B16.9	Tag nrho cov yeeb nkab teem caij ntsuas rau ASME B16.9	Tsim los kom phim lossis tshaj cov yeeb nkab khiav ntawm MSS SP-97
Kev txhawb zog	Integral - khiav thiab ceg phab ntsa muab kev txhawb zog	Integral - raws li saum toj no	Integral - weldolet muab tag nrho cheeb tsam hloov ntawm ceg
Kev faib tawm ntws	Sib npaug sib faib - ob ceg thiab khiav nqa sib npaug	Tswj txo qis - ceg me me kom txaus	Siab hloov tau ceg sizing ywj siab ntawm cov yeeb nkab khiav
Weld pob qij txha yuav tsum tau	3 (ob leeg khiav welds + ib ceg weld hauv kev sib dhos)	3 (zoo ib yam li sib npaug tee)	2 (weldolet welded mus rau khiav; ceg yeeb nkab welded rau weldolet)
Tej daim ntawv thov	Main headers, sib npaug faib manifolds	Cov txheej txheem piping ceg, ntsuas kais dej, kev siv hluav taws xob offtakes	Kub tapping, uas twb muaj lawm yeeb nkab branching, heev txo tus nqi
Tus nqi txheeb ze	Tsawg - siab- ntim khoom txheem	Tsawg mus rau nruab nrab - tus qauv catalog khoom	Nruab nrab mus rau siab - tus kheej haum thiab kev teeb tsa ua haujlwm

Source: ASME B16.9-2018 (tee dimensional data); MSS SP-97-2012 (weldolet / ceg qhov hluav taws xob specifications); Crane Technical Paper 410 (cov ntaub ntawv ntws tsis kam).

Cov ntsiab lus tseeb - Tee Xaiv:

Rau feem ntau cov txheej txheem piping ceg kev sib txuas NPS 2 thiab loj dua, qhia kom txo qis lossis sib npaug tees rau ASME B16.9 yog thawj qhov kev daws teeb meem. Weldolets ib MSS SP-97 yog qhov zoo dua thaum cov yeeb nkab khiav twb tau teeb tsa lawm (tsis txhob hloov pauv tag nrho), thaum ceg ntoo -rau- khiav piv ntau dua 1: 4, lossis thaum cov yeeb nkab khiav yog qhov loj me tsis tuaj yeem muaj raws li tee. Tsis txhob siv lub ncoo txhawb nqa (cov ceg ntoo) los hloov lub weldolet nyob rau hauv siab -siab, cyclic, los yog siab-kub qhov kev pab cuam yam tsis muaj kev ntsuam xyuas engineering.

A reduceryog ib lub yeeb nkab haum uas txuas ob lub kav dej ntawm qhov sib txawv, tso cai rau cov yeeb nkab loj hloov raws txoj kev ntws. Cov reducers tsis tuaj yeem zam tau qhov twg cov txheej txheem yuav tsum muaj kev hloov pauv hauv qhov nrawm nrawm, txoj kab uas hla ntawm cov kav dej, lossis qhov chaw sib txuas cov cuab yeej nrog qhov sib txawv nozzle ntau thiab tsawg. Ob hom yog txhais los ntawm geometry:

Reducer Fittings

Concentric Reducer:Cov kab nruab nrab ntawm cov kav loj - kawg thiab me - kawg kav yog co-axial (aligned). Lub khob hliav qab yog symmetrical nyob ib ncig ntawm cov yeeb nkab centerline. Siv rau hauv cov kav dej ntsug thiab qhov chaw nruab nrab txuas ntxiv yuav tsum tau khaws cia.

Eccentric Reducer:Qhov nruab nrab ntawm ob qhov kawg yog offset los ntawm qhov sib txawv ntawm radii. Ib sab ntawm lub reducer yog tiaj tus. Qhov tseem ceeb nyob rau hauv kab rov tav piping los tiv thaiv cov kua tsub zuj zuj (pav-sab- nce) lossis roj tsub zuj zuj (pav- sab- nqes) ntawm kev hloov.

Table 4: Concentric vs. Eccentric Reducer - Geometric thiab Application Comparison

Parameter	Concentric Reducer	Eccentric Reducer
Geometric feature	Symmetrical cone; ob lub yeeb nkab centerlines coaxial	Asymmetrical cone; ib sab tiaj; Centerlines offset los ntawm (D₁-D₂)/2
Kev tswj hwm tus qauv	ASME B16.9 (tib yam haum npog ob hom; teev los ntawm engineer)	ASME B16.9 (tib yam li concentric; orientation yog teev nyob rau hauv engineering drawings)
Ntsej muag - mus rau - lub ntsej muag ntev	Ib ASME B16.9 Table 2 - tib yam rau ob hom rau tib NPS txo	Ib ASME B16.9 Table 2 - tib yam li concentric rau tib NPS txo
Siv nyob rau hauv kab rov tav piping	Tsis nyiam - tsim hnab tshos ntawm invert; kev pheej hmoo ntawm cov kua ntxiab hauv cov pa roj lossis vapor ntxiab hauv cov kua dej	Nyiam - tiaj tus sab pem hauv ntej tiv thaiv cov kua tsub zuj zuj hauv cov kab roj; tiaj sab hauv qab tiv thaiv vapor kaw hauv cov kab ua kua
Siv hauv cov kav dej ntsug	Txheem xaiv - symmetrical ntws qauv; tsis muaj txoj kev nyiam	Tsawg dua; eccentric geometry tsis muaj qhov zoo ntawm kev khiav ntsug
Pump suction kab	Zam - tsim cov hnab tshos vapor thiab tsis sib luag qhov profile nkag mus rau lub twj tso kua mis impeller	Yuav tsum tau - tiaj- sab- nce kev taw qhia txawm tias qhov nrawm nrawm thiab tiv thaiv cavitation
Piggable pipelines	Txais tau yog tias qhov hloov pauv yog nyob rau hauv pigging tool kam rau ua	Yuav tsum tau - tiaj tus-sab- nqes kom npuaj taug kev raws lub invert yam tsis tau daig
Siab poob	Sib npaug - kwv yees li 0.5 lub taub hau rau kev txo qis (Idelchik, 2008)	Sib npaug - tib lub hydraulic poob raws li concentric rau tib NPS thiab phab ntsa lub sijhawm

Tau qhov twg los: ASME B16.9-2018 Table 2 (dimensional data); Idelchik, IE, Phau Ntawv ntawm Hydraulic Resistance, 4th ed., 2008 (siab poob coefficients); ASME B31.3-2022 Tshooj VI (qhov yuav tsum tau muaj lub tshuab nqus dej).

Cov ntsiab lus tseeb - Kev xaiv Reducer:

Eccentric reducers nrog tiaj- sab- nce kev taw qhia yog qhov yuav tsum tau ua rau tag nrho cov kab rov tav twj tso kua mis, lub ntiajteb txawj nqus- cov kab ntws, thiab cov kav dej piggable. Concentric reducers yog tsim nyog rau kev khiav ntsug, compressor suction kab hauv kev pabcuam roj, thiab qhov chaw uas qhov chaw txuas ntxiv yog xav tau los ntawm kev siv tshuab lossis txheej txheem tsim. Qhov sib txawv tsis yog tshuaj pleev ib ce - kev taw qhia tsis raug ua rau muaj teeb meem hauv cheeb tsam uas raug nqi kho tom qab kev teeb tsa.

A cev capyog ib qho haum uas kaw los yog kaw qhov kawg ntawm cov yeeb nkab. Nws yog siv los mus tas li lossis ib ntus txiav lub raj xa dej, qhov muag tsis pom lub nozzle thaum tsim kho, lossis npaj cov txheej txheem rau kev nthuav dav yav tom ntej. Caps yog ib qho ntawm cov khoom siv tseem ceeb tshaj plaws hauv cov kav dej - lawv yog tag nrho kawg - kaw cov hlab ntsha hauv lawv tus kheej txoj cai, raug rau tag nrho cov txheej txheem tsim siab thiab kub.

Steel Cap Fittings

Table 5: Pipe Cap - Cov Ntsiab Lus Specification Parameters ib ASME B16.9

Parameter	ASME B16.9 Specification - Pipe Cap
Kev tswj hwm tus qauv	ASME B16.9-2018 (lub taub qab-weld caps, NPS 1/2 txog 48); ASME B16.11 (forged threaded caps, NPS 1/8 txog 4)
Cap geometry	Hemispherical, ellipsoidal, los yog phaj taub hau daim ntawv; ASME B16.9 lub kaus mom yog tsim rau tib lub cheeb sab nraud raws li cov yeeb nkab sib txuam; sab hauv qhov tob ib lub rooj txheem
Kev ntsuas siab	Tib lub sijhawm- raws li qhov ntsuas siab raws li cov yeeb nkab sib txuam thiab lwm yam B16.9 fittings; tsis muaj qhov sib cais ntawm qhov ntsuas siab hauv ASME B16.9 - qhov ntsuas tau txais los ntawm cov kav dej thiab cov khoom siv qib
Yam tsawg kawg ntawm phab ntsa thickness	Yuav tsum tau tsawg kawg yog qhov tsawg kawg nkaus yuav tsum tau thickness ntawm cov yeeb nkab sib txuam; txheeb xyuas los ntawm cov chaw tsim tshuaj hydrostatic test los yog xam raws ASME Tshooj VIII Div. 1 cov qauv
Muaj hom kawg	Butt weld (BW) - sib tw yeeb nkab bore; Socket weld (SW) rau ASME B16.11; Xov (NPT / BSP) rau ASME B16.11
Kev cai kos cim	Yuav tsum tau cim nrog cov chaw tsim khoom lub npe / lub cim lag luam, NPS, lub sijhawm, cov khoom siv qib / UNS, tus naj npawb cua sov, ASME B16.9 tus qauv, thiab 'WP' (ua haujlwm siab) ntsuas
Kev xeem yuav tsum tau	Hydrostatic test per ASME B16.9 Tshooj 9 LOSSIS lwm NDE kev kuaj pom tau raws li kev pom zoo ntawm cov chaw tsim khoom thiab cov neeg yuav khoom
Hom khoom qib	ASTM A403 WP316L, WP304L, WP321, WP347 (austenitic SS); ASTM A815 WP2205, WP2507 (duplex); ASTM B366 WPN06625 (Alloy 625); WPN10276 (C-276)

Source: ASME B16.9-2018, Ntu 7 (qhov loj me), 9 (kuaj), thiab 10 (kos npe); ASME B16.11-2016; ASTM A403 / A403M-22; ASTM B366-22.

Cov ntsiab lus tseeb - Cap Xaiv:

Cov kaus mom yuav tsum tau teev tseg rau tib lub sijhawm thiab cov khoom siv qib raws li cov yeeb nkab uas nyob ib sab kom ntseeg tau tias qhov ntsuas qhov ntev thiab qhov ntsuas siab sib haum. Tsis txhob siv lub hau threaded ua qhov kaw ruaj khov ntawm lub pob tw -weld systems. Rau kev kaw ib ntus thaum kuaj hydrostatic lossis kev tsim kho, spectacle blinds lossis flanges dawb paug yuav zoo dua rau cov kaus mom ruaj khov, vim lawv tuaj yeem raug tshem tawm rau yav tom ntej khi -ins yam tsis tau txiav thiab rov ua dua.

A kev sib txuasyog ib qho luv luv haum nrog tib lub bore ntawm ob qho kawg, siv los koom nrog ob lub kav dej ntawm tib txoj kab uas hla lossis txuas rau lub raj xa dej. Ib nrab coupling yog threaded los yog lub qhov (socket) ntawm ib kawg thiab tawm qhov kawg qhib rau welding mus rau cov yeeb nkab khiav - nws yog qhov feem ntau haum rau ntsuas kais dej, me me txuas txuas, thiab cov ntsiab lus ntws.

Table 6: Coupling Types - Standard, Tag Nrho Coupling, Ib nrab Coupling, thiab Txo Coupling Comparison

Yam ntxwv	Puv Coupling	Ib nrab Coupling	Txo Coupling	Swage Nipple
Txuj	ASME B16.11	ASME B16.11	ASME B16.11	ASME B16.11 / MSS SP-95
Muaj nuj nqi	Koom ob qhov sib npaug - cov kav dej loj hauv kab	Ceg kev sib txuas los ntawm cov yeeb nkab khiav; ib kawg taub qab -welded khiav	Koom nrog ob lub kav dej sib txawv hauv kab	Concentric / eccentric loj txo, daim ntawv txiv mis
Xaus	SW / SW los yog NPT / NPT (qhov loj me ob qhov kawg)	SW lossis NPT ib kawg; taub qab weld lwm kawg	SW / SW lossis NPT / NPT (qhov ntau thiab tsawg)	BW los yog threaded, concentric los yog eccentric
Qhov ntau thiab tsawg	NPS 1/8 txog 4 (B16.11)	NPS 1/8 txog 4 (B16.11)	NPS 1/8 txog 4 (B16.11)	NPS 1/4 txog 6 (SP-95)
Hom kev siv	Kho, valve chaw nres tsheb, spool extensions	Instrument nozzles, ntws cov ntsiab lus, qhov cua kais dej	Cov khoom sib txuas, nozzle reducers	Compact me me txo qhov chaw txwv

Tau qhov twg los: ASME B16.11-2016, Table 1-7 (cov ntaub ntawv seem rau forged fittings); MSS SP-95-2006 (swage txiv mis thiab bull plugs).

Ib lub koom haum yog ib qho peb -daim fittings (ob qhov kawg daim thiab lub hauv paus txiv ntoo) uas tso cai rau cov yeeb nkab sib txuas ua ke thiab disassembled yam tsis tau tig cov yeeb nkab lossis cov khoom nyob ib sab. Cov koom haum yog qhov tseem ceeb nyob qhov twg cov cuab yeej yuav tsum tau tshem tawm ib ntus - twj, tswj li qub, lim dej, ntsuas ntsuas -. Qhov kawg - mus rau - qhov kawg sealing nto tej zaum yuav tiaj tus (rau threaded unions) los yog ib tug hlau - mus rau - hlau av sib koom ua ke (rau lub qhov (socket) -weld unions).

Table 7: Union Fitting - Cov Ntsiab Lus Tseem Ceeb

Parameter	Union Fitting - Specification Detail
Kev tswj hwm tus qauv	ASME B16.11-2016 (socket-weld thiab threaded unions); ASME B16.39 (malleable hlau threaded unions); MSS SP-83 (Class 3000 thiab 6000 unions)
Cov chav kawm siab	Chav Kawm 2000, 3000, 6000 (xov tooj); Chav Kawm 3000, 6000 (socket-weld) - chav kawm sib raug rau threaded haum siab ntsuas ib ASME B16.11
Sealing ntsej muag hom	Lub ntsej muag tiaj tus (threaded unions - cia siab rau sealant lossis xov kab xev); Hauv av sib koom ua ke / hlau-rau-hlau (SW unions - tsis tas yuav tsum tau sealant; nyiam rau kev huv thiab tseem ceeb)
Qhov ntau thiab tsawg	NPS 1/8 txog 4 rau lub qhov (socket) -weld thiab threaded unions ib ASME B16.11
Qhov txiaj ntsig tseem ceeb	Tso cai ua kom tiav cov raj xa dej disassembly thiab rov sib dhos ntawm ib qho kev sib koom ua ke yam tsis tau txiav - qhov tseem ceeb rau kev tswj xyuas
Kev txwv	Tsis haum raws li kev sib koom ua ke mus tas li hauv cov kav dej uas muaj kev vibration tuaj yeem loosen lub union txiv ntoo. Yuav tsum tau kuaj xyuas ib ntus thiab rov-torquing hauv cov kev pabcuam vibrating.
Cov ntaub ntawv qib	ASTM A182 F304L, F316L, F51 (2205 duplex), F60 (2507) rau forged stainless union lub cev; ASTM B462 (Alloy 625 / C-276)

Source: ASME B16.11-2016 (Nqe 4–6, kev ntsuas siab thiab qhov ntev); MSS SP-83-2006 (Union specifications); ASTM A182 / A182M-22.

Ib tug ntoo khaub lig haum (tseem hu ua plaub- txoj kev haum) muaj plaub qhov hluav taws xob ntawm 90-degree kaum rau ib leeg, tsim ib qho ntxiv kos npe. Crosses yog siv qhov twg ob lub kav dej sib tshuam ntawm tib qho chaw. Lawv tsis tshua muaj ntau dua li cov tees vim tias plaub qhov sib txuas sib txuas sib txuas ua rau muaj kev txhawj xeeb txog kev ntxhov siab, thiab plaub txoj kev sib tshuam tsis tshua xav tau hauv cov txheej txheem piping layouts. Thaum siv, lawv yuav tsum raug soj ntsuam rau kev khoov loads nyob rau hauv thermal expansion.

Lub lateral haum yog ib ceg kev sib txuas uas cov ceg tawm ntawm qhov khiav ntawm 45 degrees es tsis yog 90 degrees (raws li nrog lub tee). Laterals txo turbulence thiab siab poob ntawm ceg hlws ris piv rau tees, ua rau lawv nyiam nyob rau hauv siab- ntws, qis- siab-poob daim ntaub ntawv xws li slurry thauj thiab loj - txoj kab uas hla headers. Raws li ASME B16.9, laterals muaj nyob rau hauv vaj huam sib luag thiab txo kev teeb tsa.

Cov khoom siv qib ntawm qhov haum txiav txim siab nws qhov kev tiv thaiv corrosion, txhua yam muaj zog, qhov siab tshaj plaws kev pabcuam kub, thiab weldability. Xaiv cov qib raug yog ib qho tseem ceeb raws li xaiv hom haum haum. Cov lus hauv qab no muab cov qauv siv los ntawm EETA rau stainless hlau thiab npib tsib xee alloy yeeb nkab fittings.

Table 8: Stainless Hlau thiab Nickel Alloy Fitting Qib

Qib	UNS No.	ASTM Fitting Spec	WP npe	Cov khoom tseem ceeb	Cov ntawv thov tseem ceeb
AUSTENITIC STAINLESS STEEL Qib
304	S30400	A403	wb 304	Zoo heev general corrosion kuj; austenitic, tsis yog{0}}magnetic	Khoom noj khoom haus, dej haus, architecture, me me chemical txheej txheem
304L	S30403	A403	wb 304l	Tsawg carbon; nyiam rau welded assemblies - txo rhiab heev txaus ntshai	Pharmaceutical, zaub mov, welded yeeb nkab sib dhos
316	S31600	A403	wb 316	Mo ntxiv; superior Cl⁻ tsis kam vs . 304; PIB ~ 25	Marine, tshuaj, tshuaj, roj & roj
316L	S31603	A403	wb 316l	Tsawg carbon 316; txheem rau welded stainless systems	Offshore, pharma, zaub mov, tshuaj, feem ntau cov txheej txheem piping
321	S32100	A403	wb 321	Ti-stabilized; rau siab -kev pabcuam kub 425-900 degree	Boilers, rauv piping, siab - txheej txheem tshuaj
347	S34700	A403	wb 347	Nb-stabilized; nyiam tshaj 321 rau cyclic thermal kev pab	Kev tsim hluav taws xob, hluav taws xob hloov hluav taws xob, nuclear
904L	N08904	A403	wb 904l	High Mo+Ni; PEB ~ 36; sulfuric / phosphoric acid tsis kam	Acid nroj tsuag, seawater heat exchangers
DUPLEX & SUPER DUPLEX STAINLESS STEEL Qib
2205	S32205	A815	WP2205/WP31803	Duplex; PEB ~ 35; 2 × yield zog ntawm 316L; zoo heev SCC kuj	Roj & roj, chemical cog, offshore structures
2507	S32750	A815	wb 32750	Super duplex; PEB ~43; kev pabcuam dej hiav txwv ncaj qha	Offshore, desalination, FGD systems
NICKEL Alloy Qib
alloy 625	N06625	B366	wb 06625	PEB ~51; zoo heev pitting, crevice, SCC kuj	Offshore, aerospace, kev pabcuam tshuaj lom neeg hnyav
Alloy C-276	N10276	B366	wb 10276	PEB ~ 70; superior tsis kam mus sib xyaw aggressive media	Corrosion hnyav: acids, chlorinated, oxidizing media
alloy 825	N08825	B366	wb 08825	Kev tiv thaiv zoo rau H₂SO₄, H₃PO₄, dej hiav txwv; nqi-Ni alloy zoo	Phosphoric / sulfuric acid, dej hiav txwv, roj & roj
Alloy 400	N04400	B366	wb 04400	Ni-Cu alloy; HF acid kev pabcuam, dej hiav txwv, alkali; tsis muaj Cr	HF alkylation, marine, caustic, nkoj tsim

Tau qhov twg los: ASTM A403 / A403M-22 (austenitic SS haum qib thiab WP npe); ASTM A815 / A815M-22 (duplex / ferritic SS); ASTM B366-22 (nickel alloy fittings); ASTM A182 / A182M-22 (forged fittings, SW thiab threaded); PREN qhov tseem ceeb ntawm ASME / NACE cov ntaub ntawv cov ntaub ntawv thiab Outokumpu Stainless Steel Phau Ntawv (tsawg kawg).

Hom kev sib txuas kawg txiav txim siab li cas ib qho haum txuas mus rau cov yeeb nkab uas nyob ib sab. Txhua hom muaj qhov tshwj xeeb siab, qhov loj me, thiab kev txwv kev pabcuam. Qhov tseeb kawg kev twb kev txuas yog txiav txim los ntawm cov yeeb nkab loj, tsim siab, kev pab cuam tseem ceeb, thiab siv cov kav dej code.

Table 9: Pipe Fitting End Connection Types - Comparative Specification

Parameter	Butt Weld (BW)	Qhov (socket) Weld (SW)	Xov (NPT / BSP)
Kev tswj hwm tus qauv	ASME B16.9, ASME B16.28, EN 10253-4	ASME B16.11	ASME B16.11 (NPT: ASME B1.20.1; BSP: ISO 7-1)
NPS ntau	NPS 1/2 txog 48 (B16.9)	NPS 1/8 txog 4 (B16.11)	NPS 1/8 txog 4 (B16.11)
Cov chav kawm siab	Ib lub sijhawm ua yeeb yaj kiab (inherits yeeb nkab P-T ntsuas)	Chav Kawm 3000, 6000, 9000 ib ASME B16.11	Chav Kawm 2000, 3000, 6000 ib ASME B16.11
Kev sib koom ua ke	Siab tshaj - tag nrho nkag mus vuam; tsis muaj crevice; nruam hlau txoj kev	Siab - fillet weld; me me sab hauv crevice qhov sib txawv; txwv rau Class 6000	Tsawg tshaj plaws - txhua yam xov; yuav tsum tau sealant; muaj peev xwm rau xau ntawm xov cag
Crevice corrosion txaus ntshai	Tsis muaj - tag nrho kev sib txuas nrog tsis muaj qhov khoob	Qhov sib txawv me me ntawm lub qhov (socket) hauv qab (0.8–1.6 hli ib B16.11) - yuav tsum tau hais hauv kev pabcuam corrosive	Cov hauv paus hniav - ua rau muaj kev pheej hmoo siab hauv cov tshuaj chloride lossis acidic
Kev ntsuam xyuas hluav taws xob (RT)	Tag nrho RT ua tau rau ASME B31.3 - zoo tshaj plaws rau siab -kev ncaj ncees welds	RT tsis siv tau - fillet welds tsis tuaj yeem raug xov tooj cua; PT / MT yuav tsum tau	N/A - mechanical joint; VT thiab xau test xwb
Pom zoo kev pabcuam	High-siab, siab-kub, corrosive, cyclic, vibrating, thiab kev nyab xeeb-piping tseem ceeb. Tus qauv rau tag nrho NPS Ntau dua lossis sib npaug rau 2 hauv cov txheej txheem cov nroj tsuag.	Me- tho (NPS Tsawg dua lossis sib npaug rau 1.5) cov khoom siv hluav taws xob thiab cov cuab yeej siv. Tsis pom zoo rau cov kev pabcuam saum Chav Kawm 6000 lossis qhov chaw muaj teeb meem.	Tsawg-cov kab hluav taws xob siab, cov cuab yeej txuas, ntsuas ntsuas kais, tsis yog- kev pabcuam tseem ceeb. Tsis txhob nyob rau hauv corrosive lossis siab -kev pabcuam kub.
Code nyiam	ASME B31.3, API 6A, NACE MR0175 - taub qab vuam yog qhov ua ntej rau txhua qhov kev pabcuam tseem ceeb	ASME B31.3 tso cai SW txog NPS 2; zam hauv Qeb M kev pabcuam kua (muaj tshuaj lom heev)	ASME B31.3 tso cai rau threaded rau NPS Tsawg dua lossis sib npaug rau 1.5 hauv tsis yog- kev pabcuam hnyav nkaus xwb

Source: ASME B16.9-2018; ASME B16.11-2016, Table 1-3 (cov chav kawm siab); ASME B31.3-2022 Nqe lus 306 thiab 308 (kev sib txuas yam xav tau); ASME B1.20.1-2013 (NPT xov daim ntawv); ISO 7-1: 1994 (BSP xov daim ntawv).

Cov ntsiab lus tseeb - Xaus Kev Txuas Xaiv:

Rau tag nrho cov stainless hlau thiab npib tsib xee alloy fittings NPS 2 thiab loj dua nyob rau hauv cov txheej txheem cog kev pab cuam: qhia pob tw-weld (BW) kawg kev sib txuas rau ASME B16.9 raws li tus qauv. Rau me me - ntsuas ntsuas, ntsuas, thiab cov kab hluav taws xob NPS 1-1/2 thiab me dua: lub qhov (socket)-weld (Class 3000 lossis 6000) yog qhov siv tau qhov twg ASME B31.3 tso cai thiab qhov twg crevice corrosion tsis muaj kev txhawj xeeb. Cov xov sib txuas tau tshwj tseg rau kev pabcuam ib ntus lossis tsis tseem ceeb nkaus xwb thiab raug txwv hauv cov kev pabcuam uas muaj cov tshuaj chloride stress corrosion, HF acid, lossis Qeb M kua hauv qab ASME B31.3.

Cov kev txiav txim siab hauv qab no suav nrog kev qhia txog kev xaiv engineering los ntawm txhua ntu ua ntej rau hauv ib qho kev siv. Nws yog tsim los rau kev rho tawm ncaj qha AI thiab sau ntawv.

Table 10: Pipe Fitting Hom Xaiv Matrix

Engineering Xav tau	Pom zoo haum hom	Thawj Standard	EETA Khoom Default
Hloov ntws kev taw qhia 90℃- kev pabcuam tus qauv	Ntev vojvoog 90℃luj tshib	ASME B16.9	316L (ASTM A403 WP316L)
Hloov ntws kev taw qhia 90℃- qhov chaw- txwv	Luv vojvoog 90℃luj tshib	ASME B16.28	316L (ASTM A403 WP316L)
Hloov ntws kev taw qhia 45 degree	45℃ntev radius luj tshib	ASME B16.9	316L (ASTM A403 WP316L)
Rov qab ntws kev taw qhia hauv qhov chaw txwv	180℃rov qab (U-khoov)	ASME B16.9	316L (ASTM A403 WP316L)
Ceg kev sib txuas, tib qhov loj li khiav	Sib npaug tee	ASME B16.9	Qib matched rau cov yeeb nkab system
Ceg kev sib txuas, me dua li khiav	Txo tee lossis weldolet	ASME B16.9 / MSS SP-97	Qib matched rau cov yeeb nkab system
Txo qhov loj me - kab rov tav kav	Eccentric reducer (pav- sab- rau kua)	ASME B16.9	Qib matched rau cov yeeb nkab system
txo qhov loj me - ntsug kav	Concentric reducer	ASME B16.9	Qib matched rau cov yeeb nkab system
Pump suction loj hloov	Eccentric reducer (pav-sab-up)	ASME B16.9	2205 duplex nyob rau hauv offshore / marine
Terminate / kaw yeeb nkab kawg - mus tas li	Lub taub qab-weld cap	ASME B16.9	Qib tib yam li cov yeeb nkab uas nyob ib sab
Cov ceg me me / ntsuas kais	Ib nrab coupling (SW los yog threaded)	ASME B16.11	316L (ASTM A182 F316L forged)
Kev ruaj ntseg cov cuab yeej txuas	Union (SW los yog threaded)	ASME B16.11	316L (ASTM A182 F316L forged)
High corrosive / seawater ncaj qha kev pabcuam	LR luj tshib lossis tee, siab- qib alloy	ASME B16.9 lossis ASTM B366	2507 super duplex lossis Alloy 625
High-temperature service (>500 degree)	LR luj tshib lossis tee, ruaj khov lossis siab -Cr qib	ASME B16.9 (ASTM A403)	321 lossis 347 stainless hlau

ASME B16.9 npog cov qauv- phab ntsa pob tw- vuam fittings (Schedule 10 txog Schedule 160/XXS) rau tag nrho cov khoom siv yeeb nkab. MSS SP-43 tshwj xeeb npog lub teeb-fab ntsa stainless hlau fittings (Teem caij 5S thiab 10S nkaus xwb). MSS SP-43 fittings yog thinner-walled, qis siab ntsuas, thiab npaj rau kev siv tshuaj, khoom noj khoom haus, thiab kev siv hluav taws xob tsawg. Rau cov txheej txheem piping ntawm siab siab, ASME B16.9 siv; rau cov kav dej tsis huv lossis tsis tshua muaj siab, MSS SP-43 yog tus qauv tsim nyog.

Q: 316L fittings puas tuaj yeem welded rau 316L yeeb nkab yam tsis muaj kev tshaj tawm -weld heat treatment (PWHT)?

Yog lawm. Rau austenitic stainless hlau suav nrog 316L, PWHT feem ntau tsis tas yuav tsum tau los ntawm ASME B31.3 rau welds uas tsis pub dhau qhov kev txwv hardness. Qhov qis- cov ntsiab lus carbon ntawm 316L txo qhov kev pheej hmoo ntawm kev puas tsuaj thaum vuam. Txawm li cas los xij, rau qib duplex (2205, 2507), kev daws teeb meem annealing (tag nrho cov kev kho cua sov kho) yuav tsum tau tom qab kub sib sau los yog cov txheej txheem vuam tsim ib qho kev tsis txaus siab nyob rau hauv tshav kub - cuam tshuam cheeb tsam. Nco ntsoov sab laj txog cov txheej txheem siv cov kav dej thiab cov txheej txheem vuam (WPS) kom paub meej PWHT cov lus qhia.

Q: Dab tsi yog 'WP' txhais li cas hauv stainless hlau haum tsim (xws li WP316L)?

'WP' sawv cev rau 'Wrought Product' thiab yog ASTM cov khoom siv ua ntej siv rau cov yeeb nkab fittings npog los ntawm ASTM A403. Piv txwv li, WP316L txhais tau hais tias wrought khoom qib 316L stainless hlau, tsim rau chemistry thiab txhua yam khoom raws li ASTM A403. WP prefix distinguishes haum cov khoom specifications ntawm bar, phaj, los yog yeeb nkab khoom specifications rau tib alloy. Thaum qhia meej txog fittings, ib txwm hais txog ASTM A403 WP tus qauv nrog rau UNS tus lej kom tsis meej pem txhais cov khoom.

Q: Vim li cas thiaj yuav tsum cathode-rau-anode cheeb tsam piv rau thaum xaiv cov qib haum uas nyob ib sab rau lwm cov hlau?

Thaum stainless hlau fittings (noble, cathodic) yog nyob rau hauv kev sib cuag ncaj qha nrog cov hlau tsis muaj noble (xws li carbon steel, aluminium, los yog tooj liab alloys) nyob rau hauv ib tug electrolyte, galvanic corrosion accelerates lub dissolution ntawm cov tsis muaj noble hlau. Lub cathode-rau-anode cheeb tsam piv tswj tus nqi corrosion - ib tug loj stainless hlau nto nyob ib sab ntawm ib tug me me carbon steel tivthaiv yuav ua rau heev corrosion ntawm carbon hlau. Nco ntsoov qhia cov ntaub ntawv sib xws thoob plaws txhua qhov chaw hauv cov kav dej, lossis siv cov kev ntsuas hluav taws xob cais tawm (PTFE gaskets, cov khoom siv cais tawm) thaum tsis sib xws ntawm cov hlau sib txawv.