1. ASTM A671 CD70 Class 21 Steel Pipe yog dab tsi?
Teb:
ASTM A671 CD70 Chav Kawm 21 yog ibhluav taws xob-fusion-welded (EFW) carbon steel yeeb nkabtsim rauqis-kev pabcuam kub(hauv qab-70 ° F / -57 ° C). Cov ntsiab lus tseem ceeb:
cd70 ua: Cov khoom siv qib yuav tsum tauCharpy V- ntsuas qhov cuam tshuam ntawm -70℃Flos xyuas kom meej cryogenic toughness.
Chav Kawm 21: Yam tsawg kawg nkaus yield zog ntawm21 ksi (145 MPa), zoo tagnrho raunruab nrab-siab cryogenic systems(piv txwv li, LNG hloov kab, kev faib khoom siv roj).
2. Dab tsi yog qhov kev tsim khoom thiab ntawv pov thawj?
Teb:
Vuam: EFW txheej txheem nrog muab tub lim hlau,100% radiography (RT) lossis kuaj ultrasonic (UT)rau weld kev ncaj ncees.
Kev kho cua sov: Kev ntxhov siab-relieved los yog normalized los txhim kho qis -kub ductility.
Daim ntawv pov thawj: Mill test reports (MTRs) suav nrog:
Tshuaj ntsuam xyuas (piv txwv li, C Tsawg dua lossis sib npaug li 0.30%, Mn Tsawg dua lossis sib npaug li 1.30%).
Mechanical zog (yield / tensile zog, elongation).
Impact test results at-70℃F.
3. Chav Kawm 21 piv rau lwm chav ASTM A671 li cas?
Teb:
| Parameter | CD70 II 21 | CD70 Chav Kawm 10 | cd70 60 |
|---|---|---|---|
| Yield zog | 21 ksi (145 MPa) | 10ksi (69 MPa) | 60 ksi (414 MPa) |
| Daim ntawv thov | Nruab nrab - siab cryogenic | Tsawg- cia siab | Siab -siab cryogenic |
| Nqi | Nruab nrab -ntaus | Nyiaj txiag - phooj ywg | Hwm |
4. Dab tsi yog qhov ntev thiab qhov kam rau ua?
Teb:
Txoj kab uas hla: 16"–120" OD (tus qauv rau loj - nplai 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.
5. Yuav ua li cas txhawm rau tiv thaiv corrosion thiab ua haujlwm ntev?
Teb:
Sab nraud:
3 LPE txheej(3-txheej polyethylene) rau faus / submerged pipelines.
Cathodic tiv thaiv nyob rau hauv corrosive ib puag ncig (xws li, ntug hiav txwv dej / chaw lag luam).
Sab hauv:
Epoxy / FBE hauv ob sab phlu rau tshuaj tiv thaiv (xws li LNG nrog impurities).
Kev tu: Kev tshuaj xyuas txhua xyoo ntawm welds thiab coatings nyob rau hauv cyclic tej yam kev mob.
