Flanges kub qis yog tsim los ntawm cov khoom siv uas tau kuaj kev cuam tshuam (impact-tested materials) uas tau xaiv tshwj xeeb los tuav qhov ductility thiab fracture toughness hauv qab qhov ntau ntawm cov hlau carbon steel. Thaum qhov kub poob qis dua -20°F, ASTM A105 carbon steel yuav poob nws lub peev xwm tiv thaiv kev cuam tshuam thiab ua rau muaj kev pheej hmoo ntawm brittle fracture. Cov qib kub qis yog qhov tseem ceeb rau LNG, cryogenic, thiab arctic pipeline kev siv uas yuav tsum tau zam kev puas tsuaj los ntawm brittle fracture.
Dab tsi yog Flanges Kub Qis?
Flanges kub qis yog cov flanges uas tsim los ntawm cov khoom siv uas tau kuaj kev cuam tshuam (impact-tested) los txheeb xyuas lawv qhov fracture toughness ntawm qhov kub qis tshaj plaws uas tsim tau. Standard carbon steel (ASTM A105) hla dhau qhov ductile-to-brittle transition thaum qhov kub poob qis, poob nws lub peev xwm nqus lub zog ntawm kev cuam tshuam yam tsis muaj kev tawg. Cov qib khoom siv kub qis yog tsim nrog cov tshuaj lom neeg uas tswj tau thiab kev kho cua sov los khaws qhov ductility ntawm qhov kub qis dua xoom. Cov flanges no yog tswj los ntawm ASME B16.5 nrog cov kev xav tau ntxiv ntawm cov khoom siv uas tau teev nyob rau hauv cov code uas siv tau (ASME B31.3 rau cov kav dej ua haujlwm) thiab cov qauv khoom siv nws tus kheej.
Cov Khoom Siv Xaiv
Cov lus qhia hauv qab no qhia txog cov khoom siv flange kub qis uas feem ntau siv thiab lawv qhov kub tsawg kawg uas siv tau:
| Qauv Khoom Siv | Qib | Qhov Kub Tsawg Tshaj Plaws | Cov Yam Tseem Ceeb | Kev Siv Feem Ntau |
|---|---|---|---|---|
| ASTM A350 | LF2 | -50°F | Feem ntau carbon steel kub qis uas siv | LNG, cov kev pab cuam txias |
| ASTM A350 | LF3 | -150°F | Kev tiv thaiv kub qis zoo dua | Kev ua cov roj cryogenic |
| ASTM A182 | F304L | -425°F | Austenitic stainless, muaj peev xwm cryogenic zoo | LNG, nitrogen ua kua |
| ASTM A182 | F316L | -425°F | Low-carbon, tiv thaiv corrosion rau cryogenic | Cov kev pab cuam cryogenic uas muaj corrosion |
| ASTM A182 | F51 (2205) | -50°F | Duplex, siv tau tsawg rau kub qis | Sour gas, marine kub qis |
A350 LF2 yog hom carbon steel kub qis uas yog tus neeg ua haujlwm tseem ceeb, muab kev tiv thaiv zoo txog -50°F ntawm tus nqi qis dua A105. Rau cov kev pab cuam txias dua txog -150°F, A350 LF3 nrog nws cov ntsiab lus nickel siab dua muab kev tiv thaiv zoo dua. Rau cov kub cryogenic qis dua -150°F, austenitic stainless steels xws li F304L thiab F316L yog qhov yuav tsum tau vim lawv cov qauv ntawm lub ntsej muag-centered cubic crystal tseem muaj ductile ntawm txhua qhov kub.
Kev Ntsuas Kub thiab Siab
Cov kev ntsuas kub thiab siab rau cov flanges kub qis ua raws li cov lus qhia ASME B16.5 rau txhua pawg khoom siv. Austenitic stainless steels khaws lawv cov khoom siv zoo heev ntawm cov kub cryogenic, tiag tiag ua rau lawv muaj zog dua thaum kub qis. Carbon steel kev ntsuas txo qis heev ntawm cov kub qis, thiab qee hom khoom siv yuav raug txo qis dua qee qhov kub. Qhov kub tsawg tshaj plaws rau txhua qhov khoom siv yog txiav txim los ntawm qhov kub ntawm kev kuaj kev cuam tshuam ntawm cov khoom siv, tsis yog los ntawm kev txwv tsis theo kev cai.
Cov Kev Xav Tau Kev Ntsuas Kev Cuam Tshuam
Charpy V-Notch (CVN) kev ntsuas kev cuam tshuam yog txoj kev qhia los txheeb xyuas kev tiv thaiv kub qis. ASME B31.3 thiab ASME B16.5 xav kom kuaj kev cuam tshuam rau txhua cov carbon steel thiab low-alloy steel flanges uas siv qis dua -20°F. Qhov kev sim no yog ua rau ntawm cov qauv coj los ntawm lub flange ua tiav lossis los ntawm cov khoom ua piv txwv uas tau txais tib qhov kev kho cua sov. Cov nqi hluav taws xob tsawg kawg yog teev nyob rau hauv cov qauv khoom siv thiab txawv los ntawm hom khoom siv thiab qhov kub tsawg tshaj plaws. Qhov kub ntawm kev sim yuav tsum nyob qis dua lossis sib npaug rau qhov kub tsawg tshaj plaws. Kev ntsuas kev cuam tshuam kuj tseem yuav tsum tau ua rau ntawm cov hlau weld thiab cov cheeb tsam cuam tshuam rau cov kev ua welded.
Kev Siv
Flanges kub qis yog cov khoom tseem ceeb hauv LNG processing, khaws cia, thiab kev thauj mus los uas qhov kub tuaj yeem ncav cuag -260°F. Cryogenic gas separation thiab air liquefaction nroj tsuag cais cua rau hauv oxygen, nitrogen, thiab argon ntawm qhov kub qis heev. Refrigeration thiab cold box systems hauv cov chaw tsim tshuaj ua haujlwm ntawm qhov kub qis. Arctic thiab subarctic pipeline chaw ntsuas muaj ambient temperatures uas yuav tsum tau cov khoom siv tsis zoo ntawm tag nrho cov txheej txheem. Cov kev tswj xyuas nitrogen ua kua thiab oxygen ua kua yuav tsum muaj cov khoom siv uas tseem muaj ductile ntawm lawv qhov kub khaws cia.
Daim Ntawv Pov Thawj thiab Kev Nrhiav Tau
Cov ntawv qhia khoom (MTRs) rau cov flanges kub qis yuav tsum suav nrog cov txiaj ntsig kev ntsuas kev cuam tshuam uas qhia txog cov nqi zog nqus tau rau txhua qhov specimen. Kev nrhiav tau tag nrho los ntawm cov hlau ntu mus rau lub flange ua tiav yog qhov yuav tsum tau ua, nrog cov naj npawb kub stamped rau ntawm txhua lub flange rau kev txheeb xyuas. Kev soj ntsuam los ntawm neeg thib peb feem ntau yog teev rau cov kev pab cuam kub qis tseem ceeb los muab kev txheeb xyuas ywj pheej ntawm cov khoom siv. Positive Material Identification (PMI) kev ntsuas cov tshuaj lom neeg ua ntej kev teeb tsa muab kev qhia txog kev zoo ntxiv.
Qhov tseem ceeb yog yeej ib txwm teev cov khoom siv kub qis uas tau kuaj kev cuam tshuam rau txhua qhov kev txuas uas qis dua -20°F. Siv standard carbon steel hauv qab nws qhov kub ntawm kev hloov pauv ua rau muaj kev pheej hmoo ntawm kev puas tsuaj loj uas yuav tsum tau zam txhua tus nqi.
Xav Tau Flanges Kub Qis?
Hu rau peb pab neeg engineering rau kev xaiv flange kub qis thiab kev txhawb nqa ntawm daim ntawv pov thawj khoom.
Cov Khoom Flange
