Case 1: Yuav Ua Li Cas Thaum Flow Velocity poob qis qis?
Qhov chaw tsis ua haujlwm:Dej hiav txwv cua txias kab ntawm cov tshuaj tanker
Alloy siv:C71500 (yog rau daim ntawv thov)
Lub sij hawm ua tsis tiav:8 muaj
Failure Description
Mob hnyavnyob rau hauv - deposit corrosionthiab pitting ntawm cov ntsiab lus qis hauv cov kav dej. Lub twj tso kua mis tau loj, ua rau cov neeg ua haujlwm cuam tshuam lub valve - ua rau muaj kev cuam tshuam thiabTsawg khiav ceev (0.5 m / s).
| Parameter | Tsim tus nqi | Tus nqi ua haujlwm tiag tiag |
|---|---|---|
| Flow ceev | 2.5 – 4.0 m/s | 0.3 – 0.8 m/s |
| Dej hiav txwv kub | 25 degree | 25 degree |
| Cov yeeb nkab loj | 4" SCH 40 | 4" SCH 40 |
Keeb kwm
Copper nickel alloys yuav tsum muaj qhov tsawg kawg nkaus (Ntau dua lossis sib npaug rau 1.5 m / s rau C71500, Ntau dua lossis sib npaug rau 1.8 m / s rau C70600) kom muaj kev tiv thaiv zaj duab xis.Hauv qab no, sediment settles,
thiab localized corrosion accelerates.
Txoj kev zam
Tsim kom zoo twj tso kua mis sizing - yeej tsis cia siab rau throttling rau ceev tswj
Txhim kho cov kab recirculation thaum lub sij hawm qis ntws tsis tuaj yeem zam tau
Flush system ntawm kev tsim nrawm txhua lub lim tiam thaum lub sijhawm tsis ua haujlwm
Rau ASTM B111 C70600 tooj liab nickel yeeb nkab, qhov tsawg kawg nkaus dej hiav txwv tshaj tawm yog 1.5 m / s. Rau C71500, nws yog 1.2 m / s. Tsis txhob ua haujlwm hauv qab no cov lej.
Case 2: Yuav Ua Li Cas Ammonia Contamination Ua Cracking?
Qhov chaw tsis ua haujlwm:Fertilizer cog txias dej kub exchanger
Alloy siv:C71500 cev
Lub sij hawm ua tsis tiav:3 lis
Failure Description
TransgranularKev ntxhov siab corrosion cracking (SCC)nyob ze ntawm lub raj txuas ntxiv - mus rau - raj ntawv txuas. Cracks propagated los ntawm sab nrauv sab hauv.
| Observed Feature | Qhov taw qhia |
|---|---|
| Txoj kev tawg | Ncaj, hla cov ciam teb |
| Ib puag ncig deposit | Ntsuab -xim xiav |
| Ua haujlwm kub | 65 degree |
Keeb kwm
Cov dej txias tau kis nrog20 ppm ammonialos ntawm ib tug upstream fertilizer leak. tooj liab npib tsib xee muaj qhov tsis zoo rau ammonia - txawm tias qhov qis qis ntawm qhov kub siab ua rau SCC ceev.
Txoj kev zam
Saib xyuas cov dej txias rau NH₃ txhua lub lim tiam - qib ua haujlwm: 2 ppm
Siv titanium lossis stainless hlau yog tias muaj ammonia raug
Nruab ib qho kev tshem tawm ammonia (breakpoint chlorination)
Tsis txhob siv ASTM B111 C71500 tooj liab nickel yeeb nkab hauv txhua qhov system uas tuaj yeem ua rau muaj ammonia. Qhov no suav nrog cov nroj tsuag chiv, qee cov kwj deg refinery, thiab cov dej khib nyiab nrog urea.
Rau kev siv tsis yog - ammonia,ASTM B111 C70600 tooj liab nickel yeeb nkabmuaj qhov cuam tshuam zoo sib xws - qib tsis yog ammonia-resistant.
Case 3: Yog vim li cas Erosion -Corrosion tshwm sim txawm tias siv C71500?
Qhov chaw tsis ua haujlwm:Hluav taws kub ntiv nplhaib tseem ceeb ntawm lub platform offshore
Alloy siv:C71500 (xav tias qhov kev xaiv raug)
Lub sij hawm ua tsis tiav:14 muaj
Failure Description
Mob hnyavhorseshoe- zoo li lub qhovthiab hlau poob ntawm txhua 90℃luj tshib thiab cia li downstream ntawm ib feem qhib qhov rooj li qub.
| Qhov chaw | Phab ntsa poob (inch) | Original Phab Ntsa (SCH 40) |
|---|---|---|
| Luj tshib qhov hluav taws xob | 0.045 ″ poob | 0.154″ |
| Valve downstream sab | 0.038 ″ poob | 0.154″ |
Keeb kwm
Entrained xuab zeb (0.5-1.0% ntawm qhov hnyav)los ntawm kev haus dej hiav txwv. Txawm tias C71500 - uas ib txwm ua haujlwm txog 6 m / s hauv dej huv - tsis ua haujlwm thaum muaj xuab zeb. Lub rooj vag valve tau tso tseg 70% qhib, tsim kom muaj kev sib tw siab - dav hlau tshaj tawm.
Txoj kev zam
Nruab cov xuab zeb lim lossis hydrocyclones ua ntej cov khoom siv hluav taws xob
Siv tag nrho -chaw nres nkoj pob li qub es tsis txhob siv lub rooj vag li qub hauv dej xuab zeb
Nce phab ntsa thickness los ntawm ib tug SCH los yog BWG rau yaig nyiaj
Hloov lub luj tshib 90℃nrog ntev - vojvoog (5D) luj tshib
ASTM B111 C71500 copper nickel pipe is erosion-resistant, not erosion-proof. If sand >0.2% los ntawm qhov hnyav yog tam sim no, kab nrawm yuav tsum raug txo kom tsawg dua lossis sib npaug li 3 m / s - txawm rau C71500.
Rau cov dej huv huv,ASTM B111 C70600 tooj liab nickel yeeb nkabtsis txawm sai dua nyob rau hauv tib lub xuab zeb tej yam kev mob. C71500 yog qhov tsawg dua ntawm ob qhov kev phem, tab sis tseem tsis xuab zeb - pov thawj.
Case 4: Dab tsi yog Galvanic Failure Thaum Coupled rau Stainless Hlau?
Qhov chaw tsis ua haujlwm:Retrofit ntawm ib tsob nroj desalination nrog tov alloys
Alloy siv:C71500 cov kav dej txuas nrog 316L stainless hlau
Lub sij hawm ua tsis tiav:11 hli
Failure Description
Kev mob hnyav hauv cheeb tsam corrosion (graphitization)nyob rau sab tooj liab nickel, nyob rau hauv 2 ntiv tes ntawm stainless hlau flange sib koom. Cov hlau tsis muaj hlau tsis pom kev puas tsuaj.
| Alloy Pair | Corrosion Rate (mm / xyoo) | Tus nqi ib txwm |
|---|---|---|
| C71500 ib | <0.025 mm/yr | - |
| C71500 + 316L (tsis muaj kev sib cais) | 0.31 hli / xyoo | 12x mas |
Keeb kwm
Galvanic corrosion kuj.Stainless hlau (316L) yog ntau noble (cathodic) tshaj C71500. Hauv dej hiav txwv, cov yeeb nkab tooj liab nickel ua lub anode thiab txi nws tus kheej. Cov nyhuv muaj zog tshaj plaws nyob rau hauv thawj ob peb lub yeeb nkab diameters.
Txoj kev zam
Siv cov khoom siv cais tawm (PTFE gaskets + coated bolts) ntawm txhua qhov sib txawv ntawm cov hlau sib txuas
Khaws tsawg kawg 15 yeeb nkab diameters ntawm kev ncua deb ntawm qhov sib txawv ntawm cov hlau sib txuas
Yog tias tsis tuaj yeem sib cais, ntxiv ib qho kev txi zinc anode ze ntawm qhov sib koom ua ke
Thaum txuas ASTM B111 C71500 tooj liab nickel yeeb nkab rau stainless hlau, koj yuav tsum cais tawm. Kev cia siab rau ntawm tooj liab nickel lub hauv paus chiv keeb corrosion tsis txaus.
RauASTM B111 C70600 tooj liab nickel yeeb nkab, lub zog tsav galvanic zoo ib yam - ob leeg xav tau kev sib cais los ntawm stainless lossis titanium.
Case 5: Yuav ua li cas Weld Defects ua rau ua tsis tiav ntxov?
Qhov chaw tsis ua haujlwm:Shipboard seawater txias system retrofit
Alloy siv:C71500 (cov yeeb nkab tshiab welded rau C70600 uas twb muaj lawm)
Lub sij hawm ua tsis tiav:6 lub lis piam tom qab ua haujlwm
Failure Description
Los ntawm - phab ntsa tawgraws nraim ntawm lub tshav kub- cuam tshuam cheeb tsam (HAZ) ntawm cov vuam, tsis nyob rau hauv lub hauv paus hlau. Cov kab nrib pleb tshwm sim ntawm qhov kab nruab nrab sab hauv (dej sab).
| Weld nthuav dav | Specification | Qhov tseeb |
|---|---|---|
| Filler hlau | RN-67 (70/30 Cu-Ni) | ERCuNi (65/30) - siv tau tab sis tsis muaj kev tiv thaiv |
| Rov qab ntxuav | 100% argon | Cua (tsis muaj purification) |
| Interpass kub | <150°C | >250 degree |
Keeb kwm
Oxidation thaum vuam.Yog tsis muaj argon rov qab ntxuav, cov phab ntsa sab hauv tsim ib txheej tuab, nkig tooj liab oxide txheej. Nyob rau hauv cyclic thermal loading (30℃rau 65 degree), cov oxide tawg thiab propagated rau hauv lub hauv paus hlau.
Txoj kev zam
Ib txwm siv argon rov qab ntxuav rau tag nrho cov tooj liab nickel vuam
Tswj interpass kub - qis dua 150℃rau C71500
Siv RN-67 muab tub lim nkaus xwb; Tsis txhob siv silicon bronze lossis ntshiab tooj liab muab tub lim
Ua dye penetrant inspection (DPI) ntawm tag nrho -kev nkag welds
Ib tug raug welded ASTM B111 C71500 tooj liab nickel yeeb nkab yuav outlived cov khoom nws ua hauj lwm. Ib qho welded tsis raug yuav ua tsis tiav hauv lub hlis.
Rau vuamASTM B111 C70600 tooj liab nickel yeeb nkab, tib txoj cai siv - rov qab tshem tawm tsis yog- sib tham.
FAQ
Q1: Dab tsi yog tus lej ib qho ua rau ua tsis tiav ntxov hauv cov kav dej tooj liab nickel?
Tsawg khiav ceev los yog stagnant tej yam kev mob.Ntau tshaj li ib nrab ntawm qhov kev ua tsis tiav yog vim nyob rau hauv - deposit corrosion los ntawm sedimentation, tsis yog cov hlau nws tus kheej.
Q2: ASTM B111 C71500 tooj liab nickel yeeb nkab puas tuaj yeem ua tsis tau los ntawm pitting?
Yog, tab sis tsuas yog tias cov yeeb yaj kiab tiv thaiv puas.Qhov no tshwm sim thaum tsis tshua muaj dej, xuab zeb siab, lossis tiv tauj nrog txo cov kab mob (SRB). C71500 pits tsawg dua
C70600, tab sis tsis muaj kev tiv thaiv.
Q3: Kuv tuaj yeem qhia tau li cas yog tias kuv cov yeeb nkab C70600 uas twb muaj lawm yuav ua tsis tiav?
Ultrasonic thickness daim ntawv qhia txhua 2 xyoos.Saib rau phab ntsa thinning hauv qab 70% ntawm nominal. Tsis tas li ntawd, ib qho ntsuab "weeping" stains nyob rau sab nraud qhia los ntawm - phab ntsa pitting.
Q4: Puas yog chlorination ua rau tsis ua haujlwm?
Tsis yog, tooj liab nickel tolerates 0.5-1 ppm residual chlorine zoo.Qhov tseeb, chlorination tiv thaiv biofouling. Tshaj li 3 ppm, nrawm nrawm tuaj yeem tshwm sim - tab sis qhov ntawd tsis tshua muaj nyob hauv cov dej hiav txwv.
Q5: Dab tsi yog qhov kev kho qhov yuam kev tshaj plaws?
Siv 316L stainless hlau thaj clamps ncaj qha rau ntawm tooj liab nickel yeeb nkab.Qhov no tsim cov galvanic cell uas rhuav tshem cov yeeb nkab hauv qab clamp hauv lub hlis. Siv tooj liab nickel thaj clamps los yog cais.
Q6: Kuv puas tuaj yeem siv ASTM B111 C70600 tooj liab npib tsib xee yeeb nkab hauv tib qho kev ua tsis tiav tom qab kev kho dua tshiab?
Tsuas yog tias koj kho lub hauv paus ua ntej.C70600 yog kev zam txim tsawg dua C71500. Tsis txhob downgrade ntawm C71500 rau C70600 tom qab ua tsis tiav - koj yuav tau txais kev ua tsis tiav sai dua.
Q7: Puas yog kev kho cua sov tiv thaiv SCC?
Tsis yog rau ammonia SCC.Kev ntxhov siab rau kev ntxhov siab (550–650 degree) txo qis kev ntxhov siab tab sis tsis ua rau C71500 ammonia- tiv taus. Qhov kho tsuas yog hloov pauv alloy.
Q8: Kuv yuav tshuaj xyuas li cas rau kev yaig thaum ntxov-corrosion?
Internal teb ultrasonic (IRU) los yog eddy tam sim no kuaj.Cov txheej txheem no txheeb xyuas cov phab ntsa poob ua ntej xau tshwm sim. Ua qhov no txhua xyoo rau siab - kab nrawm.
Q9: Dab tsi yog qhov kev cia siab ntawm kev siv C71500 hauv dej hiav txwv?
20-40 xyoo.Ntau lub nkoj muaj thawj C71500 piping tom qab 30 xyoo. Kev ua tsis tiav ib txwm taug qab rov qab rau kev tsim lossis kev ua haujlwm yuam kev, tsis yog cov hlau.
Q10: Yog tias kuv twb tau ua tsis tiav nrog C70600, kuv puas yuav hloov mus rau C71500?
Yog, tab sis tsuas yog tias lub hauv paus ua rau yog nrawm lossis yaig.Rau ammonia lossis galvanic tsis ua haujlwm, C71500 yuav ua tsis tau sai li sai tau. Txhim kho qhov system ua ntej, tom qab ntawd hloov kho.
