Iivalvu zokutywina: Ungazikhetha njani izihlalo zeevalvu zePTFE, EPDM, kunye nePFA?

1: Ngowuphi umahluko obalulekileyo phakathi kwezinto ze-PTFE, i-EPDM kunye ne-PFA?

I-PTFE (iPolytetrafluoroethylene):Eyaziwa ngokuba yinkosi yeplastiki, sisixhobo esimhlophe esiqinileyo esinokungangeni kakuhle kweekhemikhali kunye nokumelana nobushushu (-196℃ ~ + 200℃). Sinomlinganiselo ophantsi kakhulu wokungqubana, kodwa ubume baso buthambile kwaye abuxhathisi ukuguguleka kunye noxinzelelo oluphezulu.

I-EPDM (i-ethylene propylene diene monomer):Irabha emnyama elastiki. Inzuzo ephambili kukuxhathisa kakuhle amanzi ashushu, umphunga, iasidi kunye nealkali (iasidi ebuthathaka kunye nealkali ebuthathaka) kunye nokuxhathisa imozulu. Ingxaki kukuba ayixhathisi kwioyile yeminerali kunye nezinyibilikisi zehydrocarbon.

I-PFA (i-perfluoroalkoxy resin):i-PTFE eguqulweyo enokunyibilika. Ukusebenza kwayo kufana ne-PTFE, kodwa ukumelana kwayo namaqondo obushushu aphezulu kuphezulu (+260°C), kwaye ingenziwa ibe sisihlalo sevalvu esixineneyo esinomphezulu ogudileyo ngokufaka i-injection molding. Ukumelana kwayo nokuqhekeka kunye nokumelana kwayo nokuqhekeka kungcono kune-PTFE.

2: Ngokuphathelele ukuhambelana kwemidiya, zeziphi izinto ezisetyenziswayo ezifanelekileyo?

I-PTFE: Isebenza phantse kuzo zonke ii-asidi ezinamandla, iziseko ezinamandla, kunye nezinyibilikisi ze-organic, kodwa ayifanelekanga kwiintsimbi ze-alkali ezinyibilikisiweyo kunye negesi ye-fluorine eshushu kakhulu.

I-EPDM:Ifanelekile kakhulu kumanzi ashushu, umphunga, ioyile ye-hydraulic ye-phosphate ester, ulwelo lwe-brake, ii-asidi ezibuthathaka kunye neziseko. Akuvumelekanga ngokungqongqo ukusebenzisa iioyile ezisekelwe kwi-petroleum (ipetroli, idizili), i-toluene, kunye nee-asidi ezixineneyo.

I-PFA:Inamandla okuxhathisa ukugqwala e-PTFE kwaye izinzile ngakumbi xa ishushu kakhulu kwaye icinezelekile. Ifanelekile ngakumbi kwiikhemikhali ezicocekileyo kakhulu (ezifana ne-sulfuric acid ecocekileyo kakhulu kunye ne-nitric acid esetyenziswa kwishishini le-semiconductor).

3: Ungakhetha njani phakathi kwezi zinto zintathu ngokweempawu zomzimba?

Ukutywina:I-EPDM > PTFE ≈ PFA. Irabha inamandla okuguquguquka okuthambileyo kunye nokunyamezela okuphezulu kwemikrwelo kumphezulu wesihlalo sevalvu; I-PTFE/PFA ifuna uxinzelelo olukhulu lokuqala lokutywina.

Ukumelana nobushushu: PFA (+260℃) > PTFE (+200℃) > EPDM (ngesiqhelo +120℃, ifomula ekhethekileyo +150℃).

Ukumelana nokunxitywa:I-PFA > PTFE > EPDM. Ii-media ezinee-particles ziya kukhawuleza ziguge isihlalo sevalvu ye-EPDM, nto leyo ebangela ukuba iswitshi ijime.

Iimfuno zeTorque:I-PTFE/PFA ine-coefficient ephantsi yokungqubana kunye ne-torque encinci yokutshintsha. I-EPDM ine-coefficient enkulu yokungqubana, nto leyo eyenza kube nzima ukuvula nokuvala ivalvu.

4: Ungenza njani izigqibo zokukhetha ngokukhawuleza ngokusekelwe kwiimeko zomsebenzi?

Inyathelo 1:Jonga ukuba ingaba le nto iqulethe ioyile na. Ukuba yioyile yeminerali okanye ioyile yefutha, khupha i-EPDM kwaye ukhethe i-PTFE okanye i-PFA.

Inyathelo lesi-2:Jonga ubushushu obuphakathi kunye nococeko. Kwiqondo lobushushu eliphezulu (>150°C) okanye iigesi ezingena kakhulu (ezifana ne-chlorine), i-PFA iyakhethwa. Ukuba ubushushu abuphezulu (<120℃) kwaye ngamanzi, umphunga okanye umoya, i-EPDM yeyona ndlela ingabizi kakhulu.

Inyathelo lesi-3:Jonga ukuba kukho naziphi na iisuntswana okanye ukutshintsha rhoqo. Ukuba ilungiswa rhoqo okanye ineesuntswana eziqinileyo, khetha i-PFA. Ukusika kube kanye kwaye akukho zisuntswana, i-PTFE yokuzikhethela.

5: Ngaba kukho into "esetyenziswa kwihlabathi liphela"?

Hayi. Ukuba ufuna ukumelana namaqondo obushushu aphezulu, ukugqwala okunamandla kunye neoyile ngaxeshanye, i-PFA lolona khetho lokuqala, kodwa ibiza kakhulu (malunga nokuphindwe kathathu ukuya kahlanu kune-PTFE) kwaye ukusebenza kwayo kokutywina akulunganga njengerabha. Ukuba i-medium ayibandakanyi ioyile kwaye ubushushu abuphezulu, i-EPDM yeyona ingabizi kakhulu. Ukhetho oluqhelekileyo oluhlala luhleli yi-PTFE.

6: Isishwankathelo

Ukukhetha izinto zokutywina ezifanelekileyo kunokwandisa ubomi bevalvu kabini.Tianjin Tanggu Water-Seal Valve Co., Ltd– igxile kwimveliso yeiivalvu zebhabhathane, iivalvu zesangokunyeiivalvu zokujonga, kwaye unobuchule ekuhlengahlengiseni izinto zokutywina ezifana ne-PTFE, i-EPDM, kunye ne-PFA kwimeko yokusebenza. Asenzi iivalvu "eziqhelekileyo", kodwa sizimisele ukubonelela ngendlela yokutywina ehlala ixesha elide nengabizi kakhulu kwimibhobho yakho nganye. Ukuba unemibuzo malunga nokukhetha,I-TWSIqela lobuchwephesha likulungele ukujonga ngokuchanekileyo ukubetha kwentliziyo yakho.