1. ASTM A671 CC70 Class 31 Steel Pipe yog dab tsi?
Teb:
ASTM A671 CC70 Chav Kawm 31 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:
CC70 ua: Cov khoom siv qib yuav tsum tauCharpy V- ntsuas qhov cuam tshuam ntawm -70℃Ftxhawm rau xyuas kom tawg tsis kam nyob rau hauv cov xwm txheej cryogenic.
Chav Kawm 31: Yam tsawg kawg nkaus yield zog ntawm31 ksi (214 MPa), haum rau nruab nrab - mus rau - siab - siab cryogenic systems.
Daim ntawv thov:LNG terminals, ethylene nroj tsuag, thiab industrial gas pipelines.
2. Dab tsi yog qhov kev tsim khoom thiab kev xeem yuav tsum tau ua?
Teb:
Vuam: EFW 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-relieved los yog normalized los txhim kho qis -kub ductility.
Yuav tsum xeem:
Charpy impact tests ntawm-70℃F.
Kev ntsuas hydrostatic siab (1.5x tsim siab).
Kev txheeb xyuas tshuaj muaj pes tsawg leeg (piv txwv li, carbon, manganese txwv).
3. Chav Kawm 31 piv rau lwm chav kawm li cas (xws li Chav Kawm 22/72)?
Teb:
| Parameter | CC70 31 | CC70 22 | CC65 qeb 72 |
|---|---|---|---|
| Yield zog | 31 ksi (214 MPa) | 22 ksi (152 MPa) | 72 ksi (500 MPa) |
| Kev ntsuas siab | Nruab nrab - siab | Tsawg | Siab heev |
| Nqi Efficiency | Sib npaug rau kev siv cryogenic | Tus nqi qis dua, kev txwv siab | Hwm rau siab zog |
4. Dab tsi yog qhov ntev thiab qhov kam rau ua?
Teb:
Txoj kab uas hla: 16 "mus rau 120" OD (ntau rau loj - nplai cryogenic pipelines).
Phab ntsa Thickness: Tolerance ntawm± 10% nominal thicknessRaws li ASTM A671.
Ntev: Txheem 40ft (12.2m), nrog kev cai ntev txog 60ft rau qhov project-cov kev xav tau tshwj xeeb.
5. Yuav ua li cas txo corrosion thiab ua kom lub neej ntev?
Teb:
Kev Tiv Thaiv Sab Nraud:
3 LPE txheej(3-txheej polyethylene) rau faus cov kav dej.
Cathodic tiv thaiv hauv cov av corrosive.
Kev Tiv Thaiv Sab Hauv:
Epoxy / FBE hauv ob sab phlu rau tshuaj tiv thaiv (xws li, hauv kev pabcuam LNG).
Kev tu: Kev tshuaj xyuas tsis tu ncua ntawm welds thiab coatings, tshwj xeeb tshaj yog nyob rau hauv thermal cycling ib puag ncig.
