Ngakhale zingawoneke ngati zazing'ono, zinthu za O-ring za valavu ndizofunikira kwambiri. Zinthuzo zimatha kudziwa kutentha kwa chisindikizo. Zimapatsanso chisindikizo mphamvu zina zotsutsana ndi mankhwala, ndipo mitundu ina ya rabara imagwirizana ndi madzi osiyanasiyana. Zipangizo ziwiri zodziwika bwino za ma valve a mpira weniweni ndi Viton ndi EPDM.

Viton (yomwe ili pachithunzi kumanja) ndi rabala yopangidwa ndi mankhwala komanso kutentha kwambiri. EPDM imayimira Ethylene Propylene Diene Monomer ndipo ili ndi zinthu zake zomwe zimapangitsa kuti ikhale chinthu chodziwika bwino cha O-ring. Poyerekeza Viton ndi EPDM, zinthu zingapo ziyenera kuganiziridwa: kupirira kutentha, kugwirizana kwa mankhwala, ndi mtengo. Werengani kuti muwerenge kufananiza konse.

Zisindikizo za raba za EPDM
Rabala ya EPDM (Rabala ya EPDM() ndi rabala yovuta komanso yotsika mtengo yomwe imagwiritsidwa ntchito m'njira zosiyanasiyana. Nthawi zambiri imagwiritsidwa ntchito poteteza madzi padenga chifukwa EPDM imatseka bwino. Ndi chinthu chofala kwambiri chotetezera madzi pa firiji chifukwa ndi chotetezera kutentha ndipo chimakhala ndi kukana kutentha kochepa. Makamaka, EPDM imagwira ntchito bwino pa kutentha kwa -49F mpaka 293F (-45C mpaka 145C), zomwe zimapangitsa kuti ikhale yoyenera kugwiritsidwa ntchito pa kutentha kulikonse.

Ngakhale kuti ma rabara ambiri sagwira kutentha kwambiri, ochepa okha ndi omwe amatha kupirira kutentha kochepa monga EPDM. Izi zimapangitsa kuti ikhale chisankho choyamba kwa aliyense amene akuyesera kutseka m'malo ozizira kapena ndi zinthu zozizira. Ma Valuvu a Mpira a True Union okhala ndiMphete Zosindikizidwa za EPDMNtchito zomwe zimagwiritsidwa ntchito kwambiri pa EPDM zimaphatikizapo kutchinjiriza magetsi, zotchingira dziwe losambira, mapaipi, zosonkhanitsa ma solar panel, ma O-rings, ndi zina zambiri.

Kuwonjezera pa kupirira kutentha kwambiri, EPDM ili ndi kukana mankhwala ambiri. Izi zikuphatikizapo madzi otentha, nthunzi, sopo, sopo wothira, sodium hydroxide, silicone oil/grease, ndi ma acid ndi mankhwala ena ambiri osungunuka. Sikoyenera kugwiritsidwa ntchito ndi zinthu zamafuta amchere monga mafuta opaka, mafuta kapena mafuta. Kuti mudziwe momwe EPDM imagwirizanirana ndi mankhwala enaake, dinani apa. Makhalidwe abwino awa, kuphatikiza ndi mtengo wake wotsika, amapangitsa EPDM kukhala chinthu chodziwika bwino chotseka.

Zisindikizo za Viton
Viton ndi rabara yopangidwa ndi elastomer ndi fluoropolymer. "Fluoropolymer" imatanthauza kuti chinthuchi chimatha kukana zinthu zosungunulira, ma acid ndi ma base. Mawu oti "elastomer" kwenikweni amasinthasintha ndi "raba". Sitikambirana kusiyana pakati pa elastomer ndi rabara pano, koma tikambirana zomwe zimapangitsa Viton kukhala yapadera kwambiri. Chinthucho nthawi zambiri chimadziwika ndi mtundu wobiriwira kapena bulauni, koma chomwe chimasiyanitsa kwambiri ndi kuchuluka kwake. Kuchuluka kwa Viton ndi kwakukulu kwambiri kuposa mitundu yambiri ya rabara, zomwe zimapangitsa kuti Viton seal ikhale imodzi mwazolimba kwambiri.

Viton imatha kupirira kutentha kwambiri kuyambira -4F mpaka 410F (-20C mpaka 210C). Kutentha kwambiri komwe Viton imatha kupirira kumapangitsa kuti ikhale yoyenera kugwiritsidwa ntchito kutentha kwambiri. Viton imagwiritsidwa ntchito kwambiri mu mphete za O, magolovesi osagwiritsa ntchito mankhwala ndi zinthu zina zopangidwa ndi ulusi kapena zotayidwa. Mphete za O zopangidwa kuchokera ku Viton ndi zabwino kwambiri posambira m'madzi, mainjini a magalimoto ndi ma valve osiyanasiyana.

Ponena za kukana mankhwala, Viton ndi yosayerekezeka. Imalimbana ndi dzimbiri kuchokera ku mitundu yosiyanasiyana ya madzi ndi mankhwala kuposa elastomer iliyonse yopanda fluorine. Mosiyana ndi EPDM, Viton imagwirizana ndi mafuta, mafuta, mafuta ndi ma inorganic acid ambiri. Imalimbananso kwambiri ndi kupsinjika, kukhuthala kwa mpweya, kuwala kwa dzuwa, kuzizira kwa nyengo, mafuta a injini okhala ndi mpweya, aromatics, bowa, nkhungu, ndi zina zambiri. Imalimbananso kwambiri ndi kuyaka kuposa rabara zina zambiri. Werengani zambiri za zoyenera ndi zosayenera kuchita ndi mankhwala a Viton.

Vuto lalikulu ndi Viton ndi mtengo wake. Pakupanga, imadula pafupifupi nthawi 8 kuposa kupanga zinthu zofanana ndi EPDM. Mukagula chinthu chomwe chili ndi zinthu zochepa chabe za rabara, mtengo wake sungasinthe kwambiri. Koma mukayitanitsa zinthu zambiri, mutha kuyembekezera kuti zida za Viton zikhale zodula kwambiri kuposa EPDM.

Zisindikizo za Viton ndi EPDM
Tchati cha Mpira Wotseka Viton vs EPDM

Ndiye ndi zinthu ziti zomwe zili bwino kwambiri? Mafunso awa si achilungamo konse. Zinthu zonsezi zili ndi ntchito zake zomwe zili zabwino, kotero zonse zimadalira ntchito yomwe adzachita. C yathuMa Vavu Oyang'anira Mpira wa PVCndipo ma CPVC Swing Check Valve amapezeka ndi ma Viton seal kapena ma EPDM seal. Ma seal awa amapangidwa ndi ma O-rings omwe amaikidwa mu fittings. Ma valve onsewa amapangidwa kuti azitha kuchotsedwa mosavuta kuti azisamalidwa mosavuta, kotero amakhala ndi matupi ochotsedwa.

Ngati mukufuna valavu ya makina oyeretsera madzi, mosasamala kanthu za kutentha, valavu yokhala ndi chisindikizo cha EPDM nthawi zambiri ndiyo yabwino kwambiri. Kupatula kusiyana pang'ono kwa kutentha, kusiyana kwakukulu pakati pa zipangizo ziwirizi ndi kukana kwawo mankhwala. Viton ndi yabwino kugwiritsidwa ntchito ndi mafuta ndi zinthu zina zowononga, koma pochita ndi chinthu chosavulaza monga madzi, kulimba kwambiri kumeneku sikofunikira.