Izivalo zamavalvu: Ungazihlukanisa futhi ukhethe kanjani izihlalo zamavalvu ze-PTFE, EPDM, kanye ne-PFA?

1: Yimuphi umehluko obaluleke kakhulu phakathi kwezinto ze-PTFE, EPDM kanye ne-PFA?

I-PTFE (i-Polytetrafluoroethylene):Ngokuvamile eyaziwa ngokuthi inkosi yamapulasitiki, iyisiqinisi esimhlophe esinokumelana okuhle kwamakhemikhali kanye nokumelana nokushisa (-196℃ ~ +200℃). Ine-coefficient ephansi kakhulu yokungqubuzana, kodwa ukuthungwa kwayo kuthambile futhi akumelani nokuguguleka kanye nokucindezela okuphezulu.

I-EPDM (i-ethylene propylene diene monomer):Irabha elimnyama elithambile. Inzuzo eyinhloko ukumelana okuhle kakhulu namanzi ashisayo, umusi, i-asidi kanye ne-alkali (i-asidi ebuthakathaka kanye ne-alkali ebuthakathaka) kanye nokumelana nesimo sezulu. Inkinga ukuthi ayimelani namafutha amaminerali kanye nezinyibilikisi ze-hydrocarbon.

I-PFA (i-resin ye-perfluoroalkoxy):I-PTFE eguquliwe ecutshungulwa ngokuncibilika. Ukusebenza kwayo kufana ne-PTFE, kodwa ukumelana kwayo namazinga okushisa aphezulu kuphakeme (+260°C), futhi ingenziwa ibe yisihlalo sevalvu esiqinile esinobuso obubushelelezi ngokubumba umjovo. Ukumelana kwayo nokuqhekeka kungcono kune-PTFE.

2: Ngokuphathelene nokuhambisana kwemidiya, yiziphi izinhlayiya ezifanelekela zona?

I-PTFE: Isebenza cishe kuzo zonke izinhlobo zama-asidi aqinile, izisekelo eziqinile, kanye nezinyibilikisi eziphilayo, kodwa ayifanele izinsimbi ze-alkali ezincibilikisiwe kanye negesi ye-fluorine eshisa kakhulu.

I-EPDM:Ifaneleka kakhulu emanzini ashisayo, umusi, uwoyela we-hydraulic we-phosphate ester, uketshezi lwamabhuleki, ama-acid abuthakathaka kanye nezisekelo. Akuvunyelwe ngokuphelele ukusebenzisa uwoyela osekelwe kuphethiloli (uphethiloli, udizili), i-toluene, nama-acid ahlanganisiwe.

I-PFA:Inamandla okumelana nokugqwala kwe-PTFE futhi izinzile kakhulu ngaphansi kokushisa okuphezulu kanye nengcindezi. Ifaneleka kakhulu kumakhemikhali amsulwa kakhulu (njenge-sulfuric acid ehlanzekile kakhulu kanye ne-nitric acid esetshenziswa embonini ye-semiconductor).

3: Ungakhetha kanjani phakathi kwezinto ezintathu ngokwezakhiwo zomzimba?

Ukuvala:I-EPDM > PTFE ≈ PFA. Irabha inekhono eliqinile lokuguquguquka nokunwebeka kanye nokubekezelela okuphezulu imihuzuko ebusweni besihlalo se-valve; I-PTFE/PFA idinga ingcindezi enkulu yokuqala yokuvala.

Ukumelana nokushisa: PFA (+260℃) > PTFE (+200℃) > EPDM (ngokuvamile +120℃, ifomula ekhethekile +150℃).

Ukumelana nokugqoka:I-PFA > PTFE > EPDM. Imidiya equkethe izinhlayiya izoguga ngokushesha isihlalo sevalvu ye-EPDM, okubangela ukuthi iswishi ijame.

Izidingo ze-torque:I-PTFE/PFA ine-coefficient ephansi yokungqubuzana kanye ne-torque encane yokushintshana. I-EPDM ine-coefficient enkulu yokungqubuzana, okwenza kube nzima ukuvula nokuvala ivalvu.

4: Ungazithatha kanjani izinqumo zokukhetha ngokushesha ngokusekelwe ezimweni zokusebenza?

Isinyathelo 1:Hlola ukuthi ngabe le nto iwuqukethe uwoyela. Uma kunguwoyela wamaminerali noma uwoyela kaphethiloli, khipha i-EPDM bese ukhetha i-PTFE noma i-PFA.

Isinyathelo 2:Hlola izinga lokushisa eliphakathi nendawo kanye nokuhlanzeka. Emazingeni okushisa aphezulu (>150°C) noma amagesi angena kalula (njenge-chlorine), i-PFA iyathandwa. Uma izinga lokushisa lingekho phezulu (<120℃) futhi kungamanzi, umusi noma umoya, i-EPDM iyindlela engabizi kakhulu.

Isinyathelo 3:Hlola ukuthi kukhona yini izinhlayiya noma ukushintsha njalo. Uma kulungiswa njalo noma kuqukethe izinhlayiya eziqinile, khetha i-PFA. Ukusika kanye kuphela futhi kungabi nezinhlayiya, i-PTFE ongayikhetha.

5: Ingabe kukhona into "ejwayelekile"?

Cha. Uma udinga ukumelana namazinga okushisa aphezulu, ukugqwala okunamandla kanye namafutha ngesikhathi esisodwa, i-PFA iyona ekhethwa kuqala, kodwa iyabiza (cishe izikhathi ezi-3-5 kune-PTFE) futhi ukusebenza kwayo kokuvala akukuhle njengerabha. Uma i-medium ingabandakanyi uwoyela futhi izinga lokushisa lingekho phezulu, i-EPDM iyona engabizi kakhulu. Ukukhetha okuvamile okulondoloziwe yi-PTFE.

6: Isifinyezo

Ukukhetha izinto zokuvala ezifanele kungandisa impilo yamavalvu kabili.I-Tianjin Tanggu Water-Seal Valve Co., Ltd– igxile ekukhiqizweni kweamavalvu ebhabhathane, amavalvu esango, futhiama-valve okuhlola, futhi unekhono ekuzivumelaniseni nezimo zokusebenza kwezinto zokuvala njenge-PTFE, i-EPDM, kanye ne-PFA. Asizenzi ama-valve "ajwayelekile", kodwa sizibophezele ekuhlinzekeni ngendlela yokuvala eqinile futhi engabizi kakhulu yamapayipi akho. Uma unemibuzo mayelana nokukhetha,I-TWSIthimba lobuchwepheshe selikulungele ukuhlola ukushaya kwenhliziyo yakho ngokunembile.