1. ASTM A671 CC70 Class 50 Steel Pipe yog dab tsi?
Teb:
ASTM A671 CC70 Chav Kawm 50 yog ibhluav taws xob-fusion-welded (EFW) carbon steel yeeb nkabtsim rauultra-tsawg- kev pabcuam kub(hauv qab-70 ° F / -57 ° C). Cov ntsiab lus tseem ceeb:
CC70 ua: Cov khoom siv qib yuav tsum tauCharpy V- ntsuas qhov cuam tshuam ntawm -70℃Fkom ntseeg tau tias muaj kev tiv thaiv cryogenic puas.
Chav Kawm 50: Yam tsawg kawg nkaus yield zog ntawm50 ksi (345 MPa), haum rausiab -cov ntawv thov kev siv tshuab siab cryogenic(piv txwv li, LNG export terminals, siab -pressure ethylene pipelines).
2. Nws tsim thiab muaj ntawv pov thawj li cas?
Teb:
Vuam: EFW txheej txheem nrog muab tub lim hlau,100% radiography (RT)los yog ultrasonic kuaj (UT) rau weld kev ncaj ncees.
Kev kho cua sov: Kev ntxhov siab -relived los yog normalized kom tau raws li qhov tsawg -kub ductility yuav tsum tau.
Daim ntawv pov thawj: Mill test reports (MTRs) suav nrog:
Tshuaj ntsuam xyuas (piv txwv li, C Tsawg dua lossis sib npaug li 0.25%, Mn Tsawg dua lossis sib npaug li 1.35%).
Mechanical zog (yield / tensile zog, elongation).
Impact test results at-70℃F.
3. Chav kawm 50 piv rau lwm chav ASTM A671 li cas?
Teb:
| Parameter | CC70 Chav Kawm 50 | CC70 22 | CC65 qeb 72 |
|---|---|---|---|
| Yield zog | 50 ksi (345 MPa) | 22 ksi (152 MPa) | 72 ksi (500 MPa) |
| Daim ntawv thov | Siab -siab cryogenic | Tsawg- cia siab | Heev -lub zog cryogenic |
| Nqi | High (premium kev ua tau zoo) | Nyiaj txiag - phooj ywg | Siab tshaj (tshwj xeeb) |
4. Dab tsi yog qhov ntev thiab qhov kam rau ua?
Teb:
Txoj kab uas hla: 16"–120" OD (tus qauv rau loj -inch cryogenic pipelines).
Phab ntsa Thickness: Ua siab ntev± 10% nominal thickness(raws li ASTM A671).
Ntev: Feem ntau 40ft (12.2m), nrog kev cai ntev txog 60ft muaj.
5. Yuav ua li cas txhawm rau tiv thaiv corrosion thiab kev nyab xeeb ntawm kev ua haujlwm?
Teb:
Sab nraud:
3 LPE txheej(3-txheej polyethylene) rau faus / offshore pipelines.
Cathodic tiv thaiv nyob rau hauv corrosive ib puag ncig (xws li, seawater raug).
Sab hauv:
Epoxy / FBE hauv ob sab phlu rau tshuaj tiv thaiv (xws li, acidic LNG paug).
Kev tu:
Kev tshuaj xyuas txhua xyoo ntawm welds thiab coatings, tshwj xeeb tshaj yog nyob rau hauv thermal / siab cycling.
