Yuav Ua Li Cas Pab Tau Lub Rooj vag Valve: Cov Tswv Yim Qhia Los ntawm Disassembly mus rau Kev Ntsuas Siab

Lub rooj vag li qub ua lub luag haujlwm tseem ceeb hauv kev qhib thiab kaw qhov nruab nrab ntws hauv cov kav dej ua haujlwm. Tom qab ua haujlwm ntev - lub sijhawm ua haujlwm, cov teeb meem tshwm sim xws li hnav lub rooj zaum sib khi, cov hlua khi thiab cov ntim ntim yuav maj mam tshwm sim. Kev saib xyuas tus qauv tuaj yeem rov qab ua haujlwm ntawm lub valve thiab txuas ntxiv nws lub neej kev pabcuam rau ntau tshaj 20 xyoo.

 

1. Ua ntej-Kev Npaj Kho Kom Zoo

Ua ntej paub meej tias lub valve yog tag nrho depressurized thiab drained, thiab siv Lockout / Tagout (LOTO) cov txheej txheem. Cov ntaub ntawv sau npe cov ntaub ntawv: nominal loj (xws li NPS 6), chav kawm siab (Class 150/300/600) thiab cov khoom siv lub cev (xws li ASTM A216 WCB cam khwb cia carbon steel). Cov kev txwv no txiav txim siab txwv torque thiab cov qauv kev sib khi rau kev saib xyuas tom ntej.

 

Cov cuab yeej yuav tsum tau & Consumables

• Torque wrench (ntau: 0 ~ 500 N·m, qhov tseeb: ± 3%)
• Lub rooj zaum grinder & lapping compound (grain loj: 240 # ~ 800 #)
• Feeler gauge (0.02 ~ 1.00 mm) rau kev ntsuas kev sib khi
• Copper gaskets los yog saj zawg zog graphite packing rings (tau nruab nrab kub: -29℃~ 425 degree)
• Xov loosening tus neeg saib xyuas rau rusted qia txiv ntoo

 

2. Cov txheej txheem disassembly (Nqa cov ntsia hlau sab nraud thiab Yoke Gate Valve ua piv txwv)

1. Tso qia thrust: Tig lub tes log counterclockwise kom qhib txoj hauj lwm, qhov twg qia nqa qhov siab sib npaug ntawm rooj vag mus ncig. Txheem mus txawv tebchaws ntawm NPS 8 Chav Kawm 300 rooj vag valve yog 305 hli. Sau cov qia ntev ntawm lub xeev qhib tag nrho rau kev txheeb xyuas qhov tseeb.
2. Tshem tawm cov khoom sib kis: Tshem tawm lub tes tsho thiab qia txiv ntoo caj pas. Kev sib kis mechanism ntawmmechanical rooj vag valvemuaj cov xov trapezoidal khub (Tr24 × 5-LH) thiab thrust bearing. Kho lub qia qis nrog nuv spanner thaum lub sij hawm disassembly kom tsis txhob xov puas.
3. Sib cais lub cev thiab lub kaus mom: lub cev xoob- lub kaus mom txuas cov ntsia liaj qhov rooj diagonally thiab maj mam los tiv thaiv lub cev deformation. NPS 6 Chav Kawm 150 valve txais 8 pcs 7/8 "-9 UNC bolts nrog tus qauv nruj torque ntawm 230 N·m.
4. Tshem tawm qia thiab rooj sib dhos: Nqa qia ua ke nrog lub rooj vag nce. Coj mus rhaub lub rooj vag sab maj mam nrog tooj dag pas nrig yog tias qhov chaw ntim tau me ntsis ntes. Rau lub qhov rooj hauv av nrog cov qia txuas ntxiv thiab lub tes tsho tsis muaj plua plav, xyuas qhov tawv tawv lossis tawg ntawm NBR/FKM O- nplhaib ntawm lub tes tsho thiab qia.

 

3. Cov Ntsiab Lus Tshuaj Ntsuam Xyuas & Kev Kho Kom Zoo

3.1 Valve Lub Cev Lub Cev & Lub Rooj Sealing Nto

• Ntsuas erosion zawj qhov tob nrog qhov tob vernier caliper; Qhov siab tshaj plaws tso cai tsawg dua los yog sib npaug li 0.25 hli, tsim- kho vuam nrog E309L lossis Inconel 625 vuam hlau yog tshaj.
• Flatness yuav tsum tau: Tsawg dua los yog sib npaug rau 0.05 mm / m rau DN200 rooj vag valve. Ua cov hmoov txhuas hmoov sib cuag nrog kev sib cuag tsis pub tsawg tshaj 75%.
• Rau cam khwb cia steel rooj vag valve, tshuaj xyuas cov khoom siv hauv qhov tsis xws li lub tshuab nqus tsev thiab lub qhov dej ntawm lub qhov txhab ntawm qhov magnifier lossis Magnetic Particle Test (MT). Valves nrog tawg ntev tshaj 10% ntawm lub cev phab ntsa thickness yog unrepairable.

 

3.2 Valve Stem & Stuffing Box

• qia deflection: Tso qia rau V- thaiv thiab ntsuas radial runout ntawm dial qhia; tso cai tus nqi Tsawg dua los yog sib npaug rau 0.1 mm / 1000 mm, ncaj los yog hloov yog tias tsis kam lees.
• Trapezoidal xov hnav: Ntsuas pitch inch nrog xov gauge; khawb qia thaum hnav tshaj 5% ntawm thawj lub suab inch (xws li thawj lub suab kab ntawm Tr28 × 5 xov yog 25.5 hli, hloov yog qis dua 24.2 hli).
• Qhov siab tshaj plaws uas tso cai rau corrosion qhov tob ntawm lub thawv ntim sab hauv phab ntsa Tsawg dua lossis sib npaug li 0.5 hli; ream tho los yog hloov lub kaus mom yog tias dhau kev txwv. Txiav txhua qhov hloov pauv graphite packing nplhaib ntawm 45℃oblique lub kaum ntse ntse thiab stagger nplhaib pob qij txha los ntawm 120℃thaum lub sijhawm teeb tsa.

 

3.3 Threaded End Kev Tshawb Fawb Kev Tshawb Fawb

Threaded kawg lub rooj vag valve nrog NPT / BSPT taper yeeb nkab threads yog feem ntau to. Ntsuas cov xov ntev thiab taper zoo; zoo xov ntev ntawm 1-nti NPT xov yuav tsum yog 16.3 ~ 17.8 hli txheeb xyuas los ntawm L1 gauge. Kho cov xov puas dua ob txoj xov tiav nrog xov chaser, qhwv 3 ~ 4 txheej ntawm PTFE daim kab xev lossis siv Loctite 567 anaerobic nplaum thaum sib dhos.

 

4. Lapping & Sib dhos

Sealing Surface Lapping Txheej Txheem

• Rough lapping: Txais 240 # silicon carbide lapping compound, rotating ceev 20 ~ 30 rpm, unidirectional lapping rau 5 ~ 8 feeb.
• Ua tiav lapping: Hloov nrog 600 # ~ 800 # pob zeb diamond lapping compound, txo qhov siab mus rau 5 ~ 10 N kom txog rau thaum qhov chaw roughness Ra tsawg dua lossis sib npaug li 0.4 μm.
• Kev tshuaj xyuas: Lub tsho tiv no xiav cov hmoov lead, sib tsoo lub rooj vag thiab lub rooj zaum rau ib lub voj voog kom tau txais kev sib cuag tsis tu ncua thiab tsis tawg.

 

Stem & Gate Assembly

Feem ntau cov neeg kho tshuab rooj vag li qub tau txais T- qhov txuas lossis tus pin txuas ntawm qia thiab lub rooj vag nrog kev sib tw tshem tawm hauv 0.10 ~ 0.25 hli. Kev tshem tawm ntau dhau ua rau muaj kev cuam tshuam lub suab nrov thaum tsis txaus tshem tawm ua rau ua raws. Siv molybdenum disulfide roj (kub tsis kam: -30 ~ 450 degree) ntawm qhov chaw sib xws thaum sib dhos.

 

Bonnet Bolt Tightening

Tighten bolts nyob rau hauv ib theem zuj zus nyob rau hauv peb theem: 50% lub hom phiaj torque → 80% lub hom phiaj torque → 100% lub hom phiaj torque. Qhov kawg torque tus nqi yuav tsum raug xam raws li ASME PCC-1 Appendix K. Piv txwv li, lubricated lub hom phiaj torque ntawm NPS 10 Chav Kawm 300 valve nrog 1-1/8 "-8 UN bolts yog 480 N·m.

 

5. Kev Ntsuas Siab (Ua raws li API 598)

Ob qhov kev ntsuas siab yuav tsum tau ua tom qab ua tiav tag nrho:

Hom kev xeem	Nruab nrab	Kuaj Siab	Tuav Sijhawm	Tso cai Leakage Rate
Kev Ntsuas Lub Cev Muaj Zog	Antirust dej	1.5 × Rated Siab	60s	Tsis pom qhov xau
High Pressure Seat Tightness Test	Dej / Cua	1.1 × Rated Siab	30s	Kua: 0 tee ib feeb; Cua: Tsawg dua lossis sib npaug li 0.3 ml / min

Rated siab siv: Chav kawm 150=1.96 MPa (285 psi), Chav kawm 300=5.1 MPa (740 psi). Teem lub valve ntawm ib nrab -qhib txoj hauj lwm kom tso pa sab hauv ua ntej kuaj, sau cov ntaub ntawv ntawm lub siab sensor nrog siab tshaj plaws poob qis dua los yog sib npaug rau 0.5% ib feeb.

 

Kev ntsuas kev nruj sab nraud yog xav tau rau lub qhov rooj nkag hauv av: Lub cev nqus dej tag nrho hauv lub tank dej, siv 0.6 MPa cua siab uas tsis muaj cua npuas khiav hauv 5 feeb. Tso cai tawm ntawm qia foob: Tsawg dua lossis sib npaug li 0.1 ml / h.

 

6. Kev daws teeb meem & Cov ntaub ntawv kaw

Fault Phenomenon	Ua Tau	Kev Kho Kom Zoo	Siv Parameter
Handwheel daig	Hnav & deformed qia xov	Hloov bronze qia txiv ntoo	Matching clearance: 0.05 ~ 0.15 hli
Ua tsis tiav kaw kaw	Particle deposit los yog khawb rau ntawm qhov chaw sealing	Re-lap sealing nto	Qhov siab tshaj plaws lapping qhov tob Tsawg dua lossis sib npaug li 0.3 hli
Packing leakage	Kev laus packing los yog gland preload tsis txaus	Hloov cov graphite rings saj zawg zog thiab compress tusyees	Gland bolt torque: 20 N·m (NPS 2)
Tsis ruaj khov qia lifting	Tsis muaj lubrication los yog xov burrs	Ntxuav cov xov thiab siv lithium puag roj	Kinematic viscosity: 220 cSt @ 40 degree

 

Txuas daim ntawv saib xyuas ntawm lub cev valve tom qab ua tiav, kos lub hnub txij nkawm, ntsuas siab thiab tus lej xov tooj. Rau cov neeg kho tshuab lub rooj vag valve, ntxiv rau cov ntaub ntawv thrust bearing clearance (tus qauv Tsawg dua los yog sib npaug ntawm 0.08 mm) thiab qhov tseeb qhib -kaw torque (xws li qhuav-lub xeev kev khiav hauj lwm torque ntawm NPS 8 Chav Kawm 150 lub rooj vag valve yog li 120 N·m, txo rau 45 N·m tom qab lubrication).

 

7. Kev saib xyuas cov ntsiab lus tseem ceeb ntawm ntau hom rooj vag Valve

Hom Valve	Tshwj xeeb txaus ntshai	Kho kom haum
Cast Steel Rooj vag Valve	Casting defects, vuam residual kev nyuaj siab tawg	Tshaj tawm -weld preservation kho ntawm 610 ± 15℃rau 2 teev
Screw End Rooj vag Valve	Rust qaug dab peg ntawm kev sib txuas threads	Txais yuav hydraulic txiv ntoo cutter, tsis txhob ua phem yeeb nkab ciaj ntswj
Underground Rooj vag Valve	Cov dej thiab cov dej nkag nkag mus rau hauv lub tes tsho	Nruab ob V- hom ntim cov nplhaib thiab sau cov roj tiv thaiv- xeb
Mechanical Gate Valve	Gearbox thiab reducer hnav	Xyuas kom cov iav tiv thaiv kab mob ntau dua lossis sib npaug li 40% thiab hloov cov roj lubricating

Xaus

Kev saib xyuas lub rooj vag valve yog kev ua haujlwm raws li cov ntaub ntawv raug thiab cov qauv kev lag luam. Txhua tus txheej txheem suav nrog kev kaw lub suab kaw, tom qab-lapping roughness detection thiab API 598 kev ntsuas siab ncaj qha txiav txim siab ua haujlwm ruaj khov ntawm li qub hauv lub voj voog txij nkawm tom ntej.

Cov rooj vag sib txawv xws li cam khwb cia steel lub cev hom, threaded kawg hom, underground ntsia hom thiab txhua yam kis tau tus mob hom muaj tshwj xeeb saib xyuas tsis.

 

Nws raug nquahu kom cov neeg ua haujlwm saib xyuas tsim cov ntaub ntawv pabcuam valve rau tus kheej los sau cov txiaj ntsig tshem tawm, cov ntaub ntawv torque thiab cov txiaj ntsig ntawm txhua qhov kev kho dua tshiab, txhawm rau paub txog kev saib xyuas kev kwv yees thiab txo qis kev pheej hmoo kaw tsis tau.