Isiciko esincinci ngaphakathi kwevalvu yakho siyasilela, nto leyo ebangela ukuvuza okukhulu. Oku kusilela okungalindelekanga kukhokelela ekubeni inkqubo ingasebenzi, umonakalo obiza kakhulu, kunye nabathengi abangonwabanga abatyhola imveliso yakho ngokuba nempazamo.

Khetha i-EPDM kwiintlobo ngeentlobo zezicelo ezisekelwe emanzini, ingakumbi xa kukho ukuvezwa ngaphandle, ilanga, okanye i-ozone. Khetha i-NBR kwiintlobo ngeentlobo zezicelo eziquka iioyile, amafutha, amafutha, okanye ulwelo olusekelwe kwi-hydrocarbon. Ukhetho olufanelekileyo luxhomekeke ngokupheleleyo kulwelo kunye nendawo engqongileyo.

Bendithetha neqabane lam uBudi malunga nengxaki enye yabathengi bakhe eyayinayo. Babebonelela ngeevalvu zomsebenzi wokufuya iintlanzi e-Indonesia owawusebenzisaiijenereyitha ze-ozoneukugcina amanzi ecocekile. Emva kweenyanga ezimbalwa, iivalvu zaqala ukuvuza. Ingxaki yayingengomzimba wevalvu; yayizii-NBR seals eziqhelekileyo ngaphakathi. I-ozone yayihlasela irabha, iyenza ibe buthathaka. Sabacebisa ukuba batshintshele kwiivalvu ezinee-EPDM seals, kwaye ingxaki yasonjululwa ngoko nangoko. Ziinkcukacha ezincinci zezinto ezibonakalayo ezimisela impumelelo okanye ukungaphumeleli kweprojekthi.

Yeyiphi engcono, i-EPDM okanye i-NBR?

Ubona iindlela ezimbini zokutywina ivalvu, kwaye ukhetho lwe-NBR lubiza kancinci. Uyalingeka ukuba ukhethe lona ukuze wonge iindleko, kodwa uxhalabile ukuba kusenokwenzeka ukuba asisosigqibo sifanelekileyo.

Akukho nanye kwezi zinto ingcono kakhulu; zenzelwe imisebenzi eyahlukeneyo. I-EPDM ingcono kakhulu kumanzi, imozulu, kunye nokumelana nobushushu. I-NBR ingcono kakhulu kukumelana neeoyile, amafutha kunye neegrisi.

Ukucinga ukuba enye "ingcono" yimpazamo eqhelekileyo. Ukhetho lumalunga nokuhambelana kweekhemikhali.I-EPDM (i-Ethylene Propylene Diene Monomer)inesakhiwo seekhemikhali esizinzileyo kakhulu esenza ukuba ikwazi ukumelana kakhulu nemozulu, ukukhanya kwelanga (UV), i-ozone, kunye namanzi ashushu nabandayo. Oku kuyenza ibe lukhetho olufanelekileyo kumashishini amaninzi anxulumene namanzi afana nokunkcenkceshela, amachibi okudada, kunye nemibhobho ngokubanzi.I-NBR (iNitrile Butadiene Rubber)Kwelinye icala, yaziwa ngokuxhathisa kwayo kakuhle kwiioyile, amafutha, kunye namafutha asekelwe kwi-petroleum. Nangona kunjalo, iyaphuka ngokukhawuleza xa ivezwa kwi-ozone kunye nokukhanya kwe-UV. Ngoko ke, ukuba ivalvu yeyomgca wamanzi, i-EPDM yeyona ndlela ilungileyo. Ukuba yeyokusetyenziswa kweoyile eziphathwayo okanye iikhemikhali ezithile, i-NBR yeyona mpendulo ichanekileyo.

Yintoni umahluko phakathi kwerabha ye-EPDM kunye ne-PVC?

Umthengi wakho ubuza "ngerabha" ekwivalvu. Kulula ukudideka phakathi kweplastiki eqinileyo yomzimba wevalvu kunye nezinto eziguquguqukayo ezisetyenziselwa izitywino ezingaphakathi kuyo.

Zizinto ezahluke ngokupheleleyo kwimisebenzi eyahlukeneyo. I-PVC yi-thermoplastic eqinileyo esetyenziselwa ukwenza umzimba wevalvu kunye nebhola. I-EPDM ngerabha yokwenziwa eguquguqukayo esetyenziselwa ukwenza ii-O-rings kunye nezihlalo ezenza isitywino.

Le yingongoma ebangela ukudideka rhoqo. Masenze kube lula kakhulu. Cinga ngevalvu njengomnyango. I-PVC yifreyimu yomnyango eqinileyo, eqinileyo kunye nomnyango ngokwawo. Inika isakhiwo kunye namandla. I-EPDM yirabha eguquguqukayo ekhupha imozulu ejikeleze isakhelo. Xa uvala ucango, i-weather-strip iyacinezela ukwenza isitywino esigqibeleleyo, esingangeni manzi. Awunakwenza ucango ngokususa imozulu, kwaye awunakwenza isitywino esiguquguqukayo kwisakhelo socango esiqinileyo. Kwiivalvu zethu, i-PVC ibonelela ngendlu enganyangekiyo kuxinzelelo. I-EPDM ibonelela ngendawo ethambileyo, eguquguqukayo ngaphakathi ethintela ukuhamba kwamanzi. Akukho nto ifana nesitywino "se-PVC rubber" kwezi valve; izitywino zizinto ezizodwa, ezikhethekileyo.

Yintoni umahluko phakathi kwe-EPDM kunye ne-NBR 70?

Ujonge iphepha leenkcukacha uze ubone “NBR 70″. Uyazi ukuba yintoni i-NBR, kodwa awuqinisekanga ukuba ithetha ukuthini inombolo ethi “70″ okanye ukuba ithelekiswa njani ne-EPDM.

I-“70″ kwi-NBR 70 ibhekisa kwi-durometer yayo, okanye i-hardness rating. Ibonisa ukuba irabha ilukhuni kangakanani. Zombini i-EPDM kunye ne-NBR ziza ngeendlela ezahlukeneyo zobunzima, apho i-70 Shore A iyindlela eqhelekileyo.

Inani aliyonxalenye yohlobo lwezinto ezibonakalayo; lilinganisa iimpawu zalo zomzimba. Ukuqina kweerabha ezithambileyo kulinganiswa kwi "Unxweme A"isikali." I-durometer engama-70 bubunzima obuqhelekileyo, obuphakathi kwendlela. Iqinile ngokwaneleyo ukumelana nokutyhalelwa ngaphandle kwendawo phantsi koxinzelelo kodwa isaguquguquka ngokwaneleyo ukwenza isitywino esihle. Ungafumana i-NBR 50 (ethambileyo) okanye i-NBR 90 (enzima kakhulu). Oku kuyasebenza nakwi-EPDM; unokuba ne-EPDM 70. Ngoko ke, uthelekiso lokwenyani luhlala luphakathi kwezinto ezisisiseko—I-EPDM vs. i-NBRInombolo yobunzima ikuxelela ukuba ifanelekile na kuxinzelelo lwenkqubo yakho. Kwiinkqubo ezininzi zamanzi nomoya, isitywina se-durometer esingama-70 sibonelela ngokulinganisela okugqibeleleyo kokusebenza kunye nokuqina.

Ithini iqondo lobushushu le-EPDM xa lithelekiswa ne-NBR?

Kuya kufuneka ukhethe ivalvu yenkqubo enokuba shushu kakhulu elangeni okanye ebanda kakhulu ebusika. Ukukhetha isitywini esingakwaziyo ukumelana nobushushu kuya kubangela ukuba iqhekeke kwaye ivuze.

I-EPDM inomlinganiselo ophezulu wobushushu, ngesiqhelo ukusuka kwi -50°C ukuya kwi 150°C (-58°F ukuya kwi 302°F). I-NBR inomlinganiselo olinganiselweyo, ngesiqhelo ukusuka kwi -40°C ukuya kwi 120°C (-40°F ukuya kwi 248°F).

Ukusebenza kobushushu sesona sizathu siphambili sokuba i-EPDM idla ngokuba lukhetho oluphezulu. Ukukwazi kwayo ukuhlala iguquguquka kumaqondo obushushu aphantsi kakhulu kuyenza ithembeke ngakumbi kwiindawo ezibandayo. Ubushushu bayo obuphezulu buthetha ukuba inokusingatha imigca yamanzi ashushu kwaye ayinakwenzeka ukuba yonakale kwizixhobo ezihlala elangeni elishushu. I-NBR, nangona ilungile, inokuba lukhuni kwaye iqhekeke xa ibanda kakhulu, nto leyo enokuphazamisa amandla ayo okutywina. Kumaqondo obushushu aphezulu, inokuguga kwaye iqine ngokukhawuleza kune-EPDM. Yingakho eTshayina, iivalvu ezininzi ezisemgangathweni, ezingabizi kakhulu zisebenzisa i-NBR, kodwa sihlala sicebisa i-EPDM kuyo nayiphi na inkqubo ejongene namaqondo obushushu aphezulu okanye efuna ukuthembeka kwexesha elide.

Ukuthelekisa ngokukhawuleza kwezinto zokutywina

Isiphelo

Kwiindawo ezinamanzi, imozulu, kunye nobushushu obuphezulu, khetha i-EPDM. Kwioyile kunye namafutha, khetha i-NBR. Ukufanisa isitywino nokusetyenziswa kwayo yimfihlo yevalvu yePVC ethembekileyo, ehlala ixesha elide, nengavuziyo.