ASTM A178 Welded Boiler Tubes Technical Specification
Txheej txheem cej luam
ASTM A178 Cov khoom lag luamyog tus qauv specification rauhluav taws xob-kuj-welded carbon steel boiler thiab superheater raj. Cov raj no tau tsim tshwj xeeb rau kev ua haujlwm siab - qhov kub thiab txias hauv boilers, superheaters, heat exchangers, thiab zoo xws li cov ntawv thov siab qhov kev ntseeg siab nyob rau hauv thermal stress yog qhov tseem ceeb.
Khoom Qib & Classifications
| Qib | Hom | Lub npe | Daim ntawv thov tseem ceeb |
|---|---|---|---|
| Qib A | ERW | Yam tsawg kawg nkaus carbon steel | Kev pabcuam dav dav, qis-kub boilers |
| Qib C | ERW | Carbon -manganese hlau | Nruab nrab kub & siab |
| Qib D | ERW (tshwj xeeb) * | Cov pa roj carbon- silicon steel | High -kub siv lub zog |
Lus Cim: Qib D cov raj tuaj yeem muab tau raws li ERW lossis seamless ntawm cov chaw tsim khoom xaiv.
Mechanical Properties
| Khoom | Qib A | Qib C | Qib D |
|---|---|---|---|
| Tensile zog, min | 47,000 psi (325 MPa) | 60,000 psi (415 MPa) | 60,000 psi (415 MPa) |
| Yield zog, min | 26,000 psi (180 MPa) | 37,000 psi (255 MPa) | 37,000 psi (255 MPa) |
| Elongation, min | 35% hauv 2 " | 30% hauv 2 " | 30% hauv 2 " |
Lus Cim: Cov khoom siv tshuab siv tau rau ob qho tib si longitudinal thiab transverse specimens.
Chemical Composition (ntau tshaj % tshwj tsis yog ntau yam tau teev tseg)
| Element | Qib A | Qib C | Qib D |
|---|---|---|---|
| Cov pa roj carbon | 0.18 | 0.35 | 0.27-0.34 |
| Manganese | 0.30-0.80 | 0.80-1.20 | 0.80-1.20 |
| Phosphorus | 0.035 | 0.035 | 0.035 |
| Sulfur | 0.035 | 0.035 | 0.035 |
| Silicon | - | - | 0.10-0.30 |
| Cov khoom seem* | - | 0.50 max txhua | 0.50 max txhua |
Residuals: Cu, Ni, Cr, Mo, V (tag nrho Tsawg dua lossis sib npaug li 1.00% rau Qib C & D)
Cov txheej txheem tsim khoom tshwj xeeb
Tshwj xeeb ERW Production:
Precision Sawb Kev Npaj- Kaw chemistry thiab kev tswj qhov ntev dua li cov yeeb nkab txheem
Kev npaj huv Edge- Qhov tseem ceeb rau siab- kev ncaj ncees welds hauv nyias- phab ntsa hlab
Siab -Vuam zaus- Feem ntau 300-450 kHz rau kev tswj xyuas kom sov
Weld Flash Tshem Tawm- Kev tshem tawm sab hauv / sab nraud kom tiav rau qhov chaw du
Sizing & Straightening- Qhov tseeb heev rau lub raj ntim haum-nce
Kev kho cua sov- Feem ntau kev ntxhov siab txo qis los yog ua kom zoo rau qhov ruaj khov
Kev kuaj tsis raug- Yuav tsum tau ua kom tiav -ntev soj ntsuam
Kev tsom xam zoo:
Kev huv huv- Tsawg qhov suav nrog thiab qhov tsis xws luag
Weld Consistency- Perfect circumferential weld integrity
Dimensional Precision- Tight tolerances rau lub tshav kub exchanger los ua ke
Standard Size & Dimensions
| Parameter | Standard Range | Cov yam ntxwv tseem ceeb |
|---|---|---|
| Sab nraud txoj kab uas hla | 0.75 "mus rau 5" (19.1-127mm) | Feem ntau: 1 "mus rau 2.5" |
| Phab ntsa Thickness | 0.035 "- 0.320" (0.9-8.1 hli) | Nyias-phab ntsa tsim tau zoo rau kev hloov cua sov |
| Ntev | Txog li 65 ft (20 m) raug | Ntev ntev txo cov pob qij txha hauv cov pob qij txha |
| Ua kom tiav | Txias kos los yog raws li -welded | Smooth nto rau txo fouling |
Tolerances (Raws li ASTM A178)
| Dimension | Ua siab ntev |
|---|---|
| Sab nraud txoj kab uas hla | ± 0.004 "rau D Tsawg dua lossis sib npaug rau 1" ± 0.5% ntawm OD rau D> 1" |
| Phab ntsa Thickness | +20%, -0% ntawm nominal phab ntsa (tus qauv) ± 10% muaj (nyob ze dua) |
| Ntev | +1/8", -0" rau txiav ntev |
| Tawm ntawm - ntawm - Roundness | Tsawg dua lossis sib npaug li 1% ntawm OD (nruj dua li cov yeeb nkab dav) |
| Kev ncaj | 0.010 "ib ko taw siab tshaj qhov sib txawv |
Yuav tsum tau xeem
| Kuaj | Kev xav tau | Ntau zaus | Lub hom phiaj |
|---|---|---|---|
| Hydrostatic Test | Siab=2S × t/D S=50% ntawm min yield zog Lub sijhawm ntev dua lossis sib npaug li 10 vib nas this |
Txhua lub raj | Leak nruj xyuas xyuas |
| Flattening Test | Flatten rau 3x phab ntsa thickness tsis tawg | Ob leeg rau ntau | Ductility & weld zoo |
| Rov qab Flattening Test | Tshwj xeeb rau ERW raj, qhib vuam rau kev tshuaj xyuas | Ib qho ntxiv | Internal weld defect nrhiav pom |
| Nondestructive Electric Test | Eddy tam sim no lossis lwm txoj kev pom zoo | Ntev ntev | Defect nrhiav tau thoob plaws hauv lub raj |
| Tensile Test | Ib lub tshav kub, ib phab ntsa thickness | Yuav tsum tau | Kev txheeb xyuas cov cuab yeej cuab tam |
| Hardness Test | Yeem xaiv, ib daim ntawv cog lus | Raws li tau teev tseg | Kev kuaj xyuas zoo ntxiv |
| Flaring Test | Rau cov raj < 3 "OD, tshwj xeeb nthuav dav yam tsis ua haujlwm | Ob leeg rau ntau | Formability rau lub raj expansion |
Surface Condition & Finishes
| Qhov xwm txheej | Kev piav qhia | Kev txiav txim siab thov |
|---|---|---|
| Raws li -welded | Lub teeb zeb nplai, weld seam pom | Economy qib, yuav tsum tau ntxuav hauv kev pabcuam |
| Pickled | Acid- ntxuav, ci tiav | Ntxuav saum npoo kom zoo dua cua sov |
| Txias Drawn | Smooth, ci tiav nrog nruj tolerances | Precision daim ntawv thov, txhim kho zoo li |
| Grit Blasted | Ntxuav, matte tiav | Txhim kho txheej / nplaum sib txuas |
| Galvanized | Zinc -coated (tsis tshua muaj rau boiler raj) | Kev siv tshwj xeeb corrosion |
Cov ntawv thov tseem ceeb
Boiler Systems:
Dej ntsaum Tubes- Cov phab ntsa hauv qhov cub hauv boilers
Boiler Bank Tubes- Convective heat transfer sections
Superheater Tubes- Chav ntsuas kub siab (Qib C/D)
Economizer Tubes- Feedwater preheating
Reheater Tubes- Kev kub siab nruab nrab ntawm chav rov ua kom sov
Thaum tshav kub kub Exchangers:
Plhaub & Tube Thaum tshav kub kub Exchangers- Txheej txheem cua sov/txias
Cua Preheaters- Combustion cua cua sov
Condenser- Steam condensation systems
Cov Khoom Siv Hluav Taws Xob Hluav Taws Xob- Kev siv hluav taws xob zoo
Lwm yam kev siv:
Sootblower Tubes- Boiler tu tshuab
Burner Tubes- Roj / cua xa hauv tshuab hluav taws xob
Refinery rhaub- Cov txheej txheem cua sov thiab lub qhov cub
Cogeneration Systems- Cov cua sov thiab lub zog sib xyaw ua ke
Kev ntsuas kub thiab siab ntsuas
| Qib | Qhov kub siab tshaj plaws | Kev txiav txim siab siab |
|---|---|---|
| Qib A | Tsawg dua lossis sib npaug rau 800℃F (427 degree) | Tsawg mus rau nruab nrab siab |
| Qib C | Tsawg dua lossis sib npaug li 850℃F (454 degree) | Nruab nrab siab, kev pabcuam dav dav |
| Qib D | Tsawg dua lossis sib npaug rau 900℃F (482 degree) | Muaj peev xwm kub dua |
Lus Cim: Cov txiaj ntsig kev ntxhov siab uas muaj nyob hauv ASME Boiler thiab Pressure Vessel Code Tshooj II, Ntu D
Sib piv nrog Lwm Cov Qauv
| Parameter | ASTM A178 Cov khoom lag luam | ASTM A53 | ASTM A214, ASTM A214 |
|---|---|---|---|
| Kev siv thawj zaug | Boilers, superheaters | General hom phiaj yeeb nkab | Condenser, tshav kub exchanger raj |
| Weld Quality Focus | Siab tshaj (kev pabcuam tseem ceeb) | Txuj | Siab |
| Kev ntsuas kub | Siab dua (tsawg dua lossis sib npaug li 900℃F) | qis dua (tsawg dua lossis sib npaug li 400℃F) | Nruab nrab |
| Dimensional Tolerances | Tighter | Txuj | Tighter |
| Kev Xeem Rigor | Feem ntau dav | Basic | Nruab nrab |
| Nqi | Siab dua | qis | Nruab nrab |
Qhov zoo ntawm ASTM A178 ERW Tubes
High Temperature Performance- Tshwj xeeb tsim los rau kev pabcuam thermal
Zoo heev Weld Integrity- Kev xeem nruj kom ntseeg tau
Kev Hloov Kub Kub Zoo- Cov npoo du thiab cov phab ntsa zoo ib yam
Ntev Ntev Muaj- Txo cov pob qij txha hauv cov pob qij txha
Pov Thawj Kev Ntseeg- Cov keeb kwm ntev hauv kev siv boiler tseem ceeb
Nqi vs. Seamless- Kev lag luam ntau dua seamless rau ntau daim ntawv thov
Kev txwv & kev txiav txim siab tsim
Kev txwv qhov loj- Ntau tshaj OD feem ntau 5" (qhov loj dua feem ntau seamless)
Tsis yog rau Severe Corrosion- Cov qib txheem tsis yog rau ib puag ncig corrosive heev
Weld Zone Kev txiav txim siab- Cov khoom sib txawv me ntsis hauv HAZ
Kub Cycling- Tej zaum yuav xav tau kev txiav txim siab tshwj xeeb rau kev caij tsheb kauj vab hnyav
Tsis yog rau Direct Flame Impingement- Hauv qee qhov qauv tsim, seamless yuav raug teev
Installation & Fabrication Guidelines
Tube Expanding:
Expansion Ratio- Feem ntau 3-8% ntawm lub raj phab ntsa thickness
Lubrication- Yuav tsum tau tiv thaiv galling
Ib ntus- Nthuav tawm ntawm nruab nrab sab nraud hauv cov ntawv raj
Kev pov thawj- Rub- tawm cov kev ntsuam xyuas pom zoo rau cov ntawv thov tseem ceeb
Vuam:
Cov txheej txheem- Yuav tsum tsim nyog rau daim ntawv thov boiler raj
Filler Hlau- Feem ntau txuam nrog cov deoxidizers
Ntxuav- Tseem ceeb heev kom tshem tawm cov oxides thiab cov kab mob
Tshaj tawm -Kev kho cua sov- Tej zaum yuav xav tau nyob ntawm daim ntawv thov
Khoov:
Yam tsawg kawg nkaus Khoov Radius- Feem ntau 3x OD rau txias khoov
Kev siv Mandrel- Pom zoo kom tsis txhob flattening
Springback Allowance- Xav txog hauv kev tsim cov cuab yeej
Kev tshuaj xyuas- Tshawb xyuas ovality thiab phab ntsa thinning tom qab khoov
Quality Assurance & Documentation
Yuav tsum tau ntawv pov thawj:
Mill Test Certificate- suav nrog kev tshuaj xyuas tshuaj lom neeg thiab kev sim tshuab
Thaum tshav kub kub Number Traceability- Qhov tseem ceeb rau kev ua raws cai ntawm boiler code
NDE Reports- Rau qhov kev sim tsis muaj kev puas tsuaj tau ua tiav
Hydrostatic Test Records- Cov ntaub ntawv siab thiab ntev
Kev Xeem Ntxiv (xaiv tau / qhov project tshwj xeeb):
Kev kuaj Ultrasonic- Ntau dua eddy tam sim no rau qee yam tsis xws luag
Kev txheeb xyuas cov khoom zoo- Tshawb xyuas chemistry ntawm cov khoom tuaj
Kev kuaj Hardness- Tshwj xeeb tshaj yog rau cov ntawv thov Qib C/D
Microstructure Examination- Rau qhov tseem ceeb heev -kub siv
Kev Ua Tsis Taus Hom & Kev Tiv Thaiv
| Hom kev ua tsis tiav | Tej Yam Ua | Kev Tiv Thaiv Kev Tiv Thaiv |
|---|---|---|
| Kev nyuaj siab Corrosion Cracking | Chlorides, caustics, residual stresses | Tsim nyog dej chemistry, txo kev ntxhov siab |
| Corrosion qaug zog | Cyclic stress nyob rau hauv corrosive ib puag ncig | Tsim kom muaj dej kom zoo, tiv thaiv corrosion |
| Ntsig | Ntev -lub sij hawm kub raug | Kev xaiv cov khoom tsim nyog, ntsuas kub |
| Weld Defect Propagation | Initial weld imperfections | Kev nruj NDE, cov txheej txheem vuam kom raug |
| Kev yaig | Siab -Veocity Particulate flow | Flow velocity control, tiv thaiv cov khoom siv |
Kev lag luam Standards & Code ua raws
Cov ntsiab lus tseem ceeb:
ASME Boiler & Pressure Vessel Code- Ntu I (Power Boilers), Ntu VIII (Lub Hwj Chim Siab)
ASME B31.1- Fais fab Piping
NBIC- National Board Inspection Code
ABMA- American Boiler Manufacturers Association cov lus qhia
Code Stamping:
S Stamp- Yuav tsum tau rau ntu I boilers
U Stamp- Rau Tshooj VIII siab hlab ntsha
NPT Stamp- National Board tau tso cai kho cov koom haum
Ordering Information
Ua kom tiav Specification yuav tsum suav nrog:
Standard & Qib- ASTM A178 Qib C ERW
Qhov ntev- OD × Phab ntsa Thickness × Length (piv txwv li, 2" × 0.120" × 20 ft)
Ua siab ntev- Txuj lossis tshwj xeeb
Ua kom tiav- Raws li -welded, pickled, txias kos
Kev sim- Cov qauv xeem thiab lwm yam kev xav tau ntxiv
Daim ntawv pov thawj- Mill xeem daim ntawv pov thawj yuav tsum tau
Kos npe- Yuav tsum muaj kev txheeb xyuas ntawm txhua lub raj
Ntim- Kev tiv thaiv kev puas tsuaj thaum xa khoom
Cov Lus Qhia Tshwj Xeeb (Tshwj xeeb yog xav tau):
Kev kho cua sov- Kev ntxhov siab, normalizing
Kev npaj kawg- Squared, deburred, chamfered
Nto tiav- Cov kev xav tau tshwj xeeb roughness
Kev tu tshwj xeeb- Degreased, passivated
Kev khaws cia- VCI daim ntawv, lub hnab desiccant rau cia
Maintenance & Life Extension
Hauv -Kev Tshawb Fawb Kev Pabcuam:
Pom kev- Saib rau corrosion, bulges, tawg
Ultrasonic Thickness- Saib xyuas phab ntsa nyias
Dye Penetrant- Nto tawg nrhiav pom
Eddy Tam sim no- Internal defect detection
Tube Sampling- Kev tshem tawm ib ntus rau kev soj ntsuam kev puas tsuaj
Txoj kev kho:
Tube Plug- Kev kho ib ntus rau kev ua tsis tiav
Tsho tes- Ntxig lub raj me me rau hauv seem uas puas lawm
Vuam Kho- Rau qee yam kev puas tsuaj (cov txheej txheem tsim nyog)
Tube Hloov- Sectional los yog tag nrho -length hloov
Environmental & Safety Considerations
Kev kho dej- Qhov tseem ceeb los tiv thaiv nplai, xeb, thiab kev tso nyiaj
Cov tshuaj ntxuav tu- Yuav tsum sib haum nrog cov khoom siv raj
Vuam Fumes- Kev ua pa kom raug thaum tsim khoom
Kev ntsuas siab- Cov txheej txheem nyab xeeb rau kev kuaj hydrostatic
Xaus- ntawm-Lub Neej- Kev pov tseg kom raug / rov ua dua ntawm cov raj siv boiler
Cov ntsiab lus
ASTM A178 ERW hlab sawv cev tshwj xeeb, siab - cov khoom zoo tsim tshwj xeeb rau kev thov siab - cov ntawv thov kub hauv boilers thiab cov khoom siv hluav taws xob. Txawm hais tias muaj kev nruj me ntsis hauv kev xav tau thiab kev sim ntau dua li qhov dav dav - lub hom phiaj yeeb nkab, lawv muaj kev ntseeg tau zoo hauv cov ntawv thov thermal tseem ceeb. Kev xaiv kom raug raws li qhov ntsuas kub, qhov siab, thiab ib puag ncig, ua ke nrog kev ua raws li cov cai siv tau thiab kev saib xyuas, ua kom muaj kev nyab xeeb thiab ua haujlwm ntev - lub sijhawm ua haujlwm.
Rau cov ntawv thov boiler, nco ntsoov sab laj nrog ASME Boiler thiab Pressure Vessel Code thiab koom nrog cov kws tshaj lij boiler tsim nyog hauv kev tsim, tsim, thiab tshuaj xyuas cov haujlwm. Cov khoom specifications muab yam tsawg kawg nkaus; Cov kev pabcuam tiag tiag tuaj yeem txiav txim siab ntxiv.
