Qhov kev nkag siab ntawm cov khoom ntawm lub valve sealing ntiv nplhaib tsis txaus. Nws yog nrawm, ntshai ntawm teeb meem, thiab nws yog qhov yooj yim rau teeb meem hauv kev teeb tsa ntawm lub nplhaib khi vim ua txhaum ntawm cov txheej txheem kev ua haujlwm, uas ua rau muaj kev cuam tshuam loj dua. Cov khoom siv foob yog ua los ntawm cov hlau (txhuas, txhuas, indium, stainless hlau, thiab lwm yam), cov khoom siv tsis yog hlau (roj hmab, yas, ceramic, graphite, thiab lwm yam), cov ntaub ntawv sib xyaw (xws li roj hmab-asbestos board, airgel xav -polyurethane), tab sis qhov siv tshaj plaws yog cov khoom siv roj hmab ua khoom siv elastomer.
Cov khoom siv sib nqus dej tau muab faib ua plaub pawg: cov ntaub ntim cov khoom sib khi, cov khoom siv tsis muaj dej tsis sib haum, cov khoom siv hluav taws xob zoo thiab cov ntsaws ruaj ruaj zoo li qub. Lawv tuaj yeem tiv taus qhov chaw ntawm kev sib koom ua ke kom ua tiav cov duab airtight thiab watertight thiab muaj nyob rau hauv cov pob qij txha ntawm cov tuam tsev. s khoom siv.
Cov khoom siv dav dav rau cov khoom siv valve foob thiab lawv cov kev siv yog raws li hauv qab no:
1. Cov roj hmab hluavtaws: Cov roj hmab hluavtaws muaj cov kev ua tau zoo dua li cov roj hmab ntuj vim tias nws cov roj tsis kam, kub thiab tiv taus corrosion. Cov roj hmab hluavtaws siv siv qhov kub thiab txias t ≤ 150 ° C, ntuj roj hmab t ≤ 60 ° C, roj hmab rau nominal siab PN ≤ 1MPa kaw lub qhov rooj, lub rooj vag valve, diaphragm valve, npauj npaim valve, kos lub valve, ntsaws valve thiab lwm yam li qub.
2. Nylon: Nylon muaj cov yam ntxwv ntawm kev sib txhuam me me thiab zoo corrosion kuj. Nylon feem ntau yog siv rau pob thiab lub ntiaj teb li qub nrog qhov kub t ≤ 90 ° C thiab nominal siab PN ≤ 32 MPa.
3. Polytetrafluoroethylene: Polytetrafluoroethylene feem ntau yog siv rau cov xau kaw, lub rooj vag, pob lub pob, thiab lwm yam nrog kub t temperature 232 ° C thiab nominal siab PN ≤ 6.4 MPa.
4. Cam khwb cia hlau: Cov cam khwb cia hlau yog siv rau lub rooj vag valve, lub ntiaj teb valve thiab ntsaws valve rau qhov kub thiab txias t ≤ 100 ° C, nom tswv siab PN ≤ 1.6MPa, roj thiab roj.
5. Babbitt alloy: Babbitt alloy yog siv rau ammonia kaw-valve nrog kub t-70 ~ 150 ° C thiab nominal siab PN ≤ 2.5MPa.
6, tooj liab tooj liab: tooj liab alloy cov khoom siv feem ntau yog 6-6-3 tin tooj dag thiab 58-2-2 manganese tooj dag. Copper alloy muaj cov coj zoo hnav thiab haum rau dej thiab chav nrog kub t ≤ 200 ° C thiab kub siab lub npe PN ≤ 1.6 MPa. Nws feem ntau siv rau rooj vag li qub, ntiaj teb li qub, kos li qub, ntsaws li qub, thiab lwm yam.
7, chrome stainless hlau: chrome stainless hlau feem ntau siv qib 2Cr13, 3Cr13 tom qab quenching thiab tempering kho, zoo corrosion kuj. Nws feem ntau siv rau hauv li qub ntawm dej, chav thiab roj av media nrog qhov kub t ≤ 450 ° C thiab nominal siab PN ≤ 32 MPa.
8. Chromium-npib tsib xee-stainless hlau: cov qeb ntawm chrome-npib tsib xee-titanium stainless hlau yog 1Cr18Ni9ti, uas muaj zoo corrosion tsis kam, yaig tiv taus thiab kub ua hauj. Nws tsim nyog siv rau hauv chav ua noj, nitric acid thiab lwm yam xov xwm nrog kub t ≤ 600 ° C thiab nominal siab PN ≤ 6.4 MPa, rau kev sib tw kaw, pob li qub, thiab lwm yam.
9. Nitrided steel: Feem ntau ntawm qib nitriding steel yog 38CrMoAlA, uas muaj qhov zoo corrosion tsis kam thiab khawb tsis kam tom qab kev kho mob carburizing. Nquag siv nyob rau hauv chaw nres tsheb fais fab rooj vag ntsuas nrog qhov kub t ≤ 540 ° C thiab nominal siab PN ≤ 10 MPa.
10. Boronizing: Boronizing yog ua ncaj qha los ntawm lub cev valve lossis cov khoom siv lub cev valve mus rau qhov chaw sib khi, thiab tom qab ntawd boronizing saum npoo kev kho mob tau ua, thiab qhov chaw sib khi tau zoo hnav tsis kam. Siv rau hluav taws xob chaw nres tsheb ntws valve.
