Nangona ingabonakala ngathi yinto encinci, izinto ze-O-ring zevalvu zibaluleke kakhulu. Izinto ezisetyenzisiweyo zinokumisela ukunyamezela ubushushu betywina. Zikwanika itywina ukumelana neekhemikhali, kwaye ezinye iintlobo zerabha ziyahambelana nolwelo olwahlukeneyo. Izinto ezimbini eziqhelekileyo zeevalvu zebhola yomanyano lokwenyani yiViton kunye neEPDM.

I-Viton (eboniswe ngasekunene) yirabha eyenziweyo enokumelana neekhemikhali eziphezulu kunye nobushushu. I-EPDM imele i-Ethylene Propylene Diene Monomer kwaye ineempawu zayo ezenza ukuba ibe yinto ethandwa kakhulu kwi-O-ring. Xa uthelekisa i-Viton ne-EPDM, kufuneka kuqwalaselwe izinto ezininzi: ukunyamezela ubushushu, ukuhambelana kweekhemikhali, kunye nexabiso. Qhubeka ufunda ukuze ufumane uthelekiso olupheleleyo.

Iisilingi zerabha ze-EPDM
Irabha ye-EPDM (Irabha ye-EPDM) yirabha entsonkothileyo nengabizi kakhulu eneendlela ezahlukeneyo zokusetyenziswa. Idla ngokusetyenziselwa ukuthintela amanzi eluphahleni kuba i-EPDM iyayivala kakuhle. Ikwayinto eqhelekileyo kwizitywini zefriji kuba iyi-insulator kwaye inokumelana okuhle kakhulu nobushushu obuphantsi. Ngokukodwa, i-EPDM isebenza ngokufanelekileyo kumanqanaba obushushu ukusuka kwi--49F ukuya kwi-293F (-45C ukuya kwi-145C), nto leyo eyenza ukuba ilungele ukusetyenziswa kuyo nayiphi na iqondo lobushushu.

Nangona iirabha ezininzi zikwazi ukumelana nobushushu obuphezulu, zimbalwa kuphela ezinokumelana nobushushu obuphantsi njenge-EPDM. Oku kwenza kube lukhetho lokuqala kuye nabani na ozama ukuvala kwiindawo ezibandayo okanye ngezinto ezibandayo. IiValve zeBhola zeTrue Union ezineIi-O-Rings ezitywiniweyo ze-EPDMIzicelo eziqhelekileyo ze-EPDM ziquka ukufakelwa kombane, ii-linings zedama lokubhukuda, imibhobho yamanzi, izinto zokuqokelela iiphaneli zelanga, ii-O-rings, nokunye.

Ukongeza ekunyamezeleni ubushushu obuphezulu, i-EPDM inokumelana okukhulu neekhemikhali. Ezi ziquka amanzi ashushu, umphunga, izicoci, izisombululo ze-caustic potash, izisombululo ze-sodium hydroxide, ioyile ye-silicone/igrisi, kunye nezinye ii-asidi ezininzi kunye neekhemikhali ezixutyiweyo. Ayifanelekanga ukusetyenziswa neemveliso zeoyile yeminerali ezifana neeoyile zokuthambisa, iioyile okanye amafutha. Ukuze ufumane ukuhambelana kweekhemikhali ezithile ze-EPDM, cofa apha. Ezi mpawu zimangalisayo, kunye nexabiso layo eliphantsi, zenza i-EPDM ibe yinto ethandwayo yokutywina.

Iiseal zeViton
I-Viton yirabha yokwenziwa kunye ne-fluoropolymer elastomer. Igama elithi “Fluoropolymer” lithetha ukuba le nto inokumelana okuphezulu nezinyibilikisi, ii-asidi kunye neziseko. Igama elithi “elastomer” ngokusisiseko linokutshintshiselana nelithi “irabha”. Asiyi kuxoxa ngomahluko phakathi kwe-elastomer kunye nerabha apha, kodwa siza kuxoxa ngento eyenza i-Viton ibe yekhethekileyo. Le nto idla ngokubonakala ngombala oluhlaza okanye omdaka, kodwa eyona nto iyenza yahluke kakhulu kuxinano lwayo. Uxinano lwe-Viton luphezulu kakhulu kuneentlobo ezininzi zerabha, nto leyo eyenza i-Viton seal ibe yenye yezona zinamandla.

I-Viton inomlinganiselo omkhulu wokunyamezela ubushushu ukusuka kwi--4F ukuya kwi-410F (-20C ukuya kwi-210C). Ubushushu obuphezulu obunokunyanyezelwa yi-Viton buyenza ilungele ukusetyenziswa kubushushu obuphezulu. I-Viton isetyenziswa kakhulu kwii-O-rings, iiglavu ezimelana neekhemikhali kunye nezinye iimveliso ezibunjiweyo okanye ezikhutshiweyo. Ii-O-rings ezenziwe nge-Viton zilungele ukuntywila kwi-scuba, iinjini zeemoto kunye neevalvu ezahlukeneyo.

Xa kufikwa ekuchaseni iikhemikhali, iViton ayinakuthelekiswa nayo. Iyachasana nokugqwala okuvela kwiintlobo ngeentlobo zolwelo kunye neekhemikhali kunayo nayiphi na i-elastomer engenafluorinated. Ngokungafaniyo ne-EPDM, iViton iyahambelana neeoyile, amafutha, izinto zokuthambisa kunye nee-asidi ezininzi ezingaphiliyo. Ikwachasana kakhulu nokucinezelwa, i-atmospheric oxidation, ilanga, imozulu, amafutha eemoto aneoksijini, ii-aromatics, iifungi, isikhunta, nokunye. Ikwachasana kakhulu nokutsha kunezinye irabha. Funda ngakumbi malunga nezinto ekufuneka zenziwe kunye nezinto ekufuneka zenziwe ngeekhemikhali zeViton.

Ingxaki ephambili ngeViton lixabiso layo. Kwimveliso, ixabisa malunga nezihlandlo ezisibhozo ukwenza inani elifanayo lezinto ezifana ne-EPDM. Xa uthenga imveliso equlethe inani elincinci lezi zinto zerabha, ixabiso lisenokungatshintshi kakhulu. Kodwa xa u-odola ngobuninzi, ungalindela ukuba iindawo zeViton zibize kakhulu kune-EPDM.

Izitywino zeViton kunye neEPDM
Itshathi yerabha yokutywina yeViton vs EPDM

Ngoko ke yeyiphi eyona nto ilungileyo? Le mibuzo ayilunganga ngokupheleleyo. Zombini ezi zinto zinezicelo ezithile apho zilungele khona, ngoko ke konke kuxhomekeke kumsebenzi eziza kuwenza.Iivalvu zokujonga ibhola zePVCkunye neeValve ze-CPVC Swing Check ziyafumaneka ngee-seals zeViton okanye ii-seals ze-EPDM. Ezi seals zenziwe ngee-O-rings ezifakwe kwi-fittings. Zonke ezi valves zenzelwe ukuba zisuswe lula ukuze kube lula ukuzilungisa, ukuze zibe nee-body ezisuswayo.

Ukuba ufuna ivalvu kwinkqubo yamanzi, nokuba ingakanani na iqondo lobushushu, ivalvu ene-EPDM seal idla ngokuba lolona khetho lulungileyo. Ngaphandle kokumelana nobushushu obahlukeneyo kancinci, umahluko ophambili phakathi kwezi zinto zimbini kukumelana kwazo neekhemikhali. I-Viton ilungele ukusetyenziswa nepetroli nezinye izinto ezibolayo, kodwa xa usebenzisa into engenabungozi njengamanzi, oku kuhlala ixesha elide akufuneki.