Ukuvalwa okuncane ngaphakathi kwevalvu yakho kuyahluleka, okubangela ukuvuza okukhulu. Lokhu kwehluleka okungalindelekile kuholela ekungasebenzini kwesikhathi sohlelo, umonakalo obizayo, kanye namakhasimende angajabule asola umkhiqizo wakho ngokuthi unephutha.

Khetha i-EPDM yezinhlelo zokusebenza eziningi ezisekelwe emanzini, ikakhulukazi lapho kutholakala khona ukukhanya ngaphandle, ilanga, noma i-ozone. Khetha i-NBR yezinhlelo zokusebenza ezifaka amafutha, amafutha, amafutha, noma uketshezi olusekelwe kuma-hydrocarbon. Ukukhetha okulungile kuncike ngokuphelele oketshezini nasendaweni ezungezile.

Bengikhuluma nomlingani wami uBudi ngenkinga omunye wamakhasimende akhe ayenayo. Babehlinzeka ngama-valve omsebenzi wokufuya izinhlanzi e-Indonesia owawusebenzisaamajeneretha e-ozoneukugcina amanzi ehlanzekile. Ngemva kwezinyanga ezimbalwa, amavalvu aqala ukuvuza. Inkinga kwakungeyona umzimba wevalvu; kwakuyizivalo ze-NBR ezijwayelekile ngaphakathi. I-ozone yayihlasela irabha, iyenza iqhekeke. Sabacebisa ukuthi bashintshele kumavalvu anezivalo ze-EPDM, futhi inkinga yaxazululwa ngokushesha. Yile mininingwane emincane yezinto ezibonakalayo enquma impumelelo noma ukwehluleka kwephrojekthi.

Yikuphi okungcono, i-EPDM noma i-NBR?

Ubona izinketho ezimbili zokuvala ivalvu, kanti inketho ye-NBR ishibhile. Uyalingeka ukuba uyikhethe ukuze wonge izindleko, kodwa ukhathazekile ukuthi kungenzeka ukuthi akuyona isinqumo esifanele.

Akukho lutho olungcono kakhulu; lwenzelwe imisebenzi ehlukene. I-EPDM ingcono kakhulu emanzini, esimweni sezulu, nasekumelaneni nokushisa. I-NBR ingcono kakhulu ekumelaneni namafutha, amafutha, kanye namafutha.

Ukucabanga ukuthi into "ingcono" nje kuyiphutha elivamile. Ukukhetha kumayelana nokuhambisana kwamakhemikhali.I-EPDM (i-Ethylene Propylene Diene Monomer)inesakhiwo samakhemikhali esizinzile kakhulu esenza ukuthi imelane kakhulu nesimo sezulu, ukukhanya kwelanga (UV), i-ozone, kanye namanzi ashisayo nabandayo. Lokhu kwenza kube ukukhetha okuhle kakhulu kwezimboni eziningi ezihlobene namanzi njengokunisela, amachibi okubhukuda, kanye namapayipi ajwayelekile.I-NBR (Irabha ye-Nitrile Butadiene)Ngakolunye uhlangothi, yaziwa ngokumelana kwayo okuhle kakhulu namafutha asekelwe kuphethiloli, uphethiloli, namafutha. Kodwa-ke, iyaphuka ngokushesha uma ivezwa ekukhanyeni kwe-ozone kanye ne-UV. Ngakho-ke, uma ivalvu ingeyomugqa wamanzi, i-EPDM iyisinqumo esihle kakhulu. Uma ingeyohlelo lokuphatha uwoyela noma amakhemikhali athile, i-NBR yiyona kuphela impendulo efanele.

Uyini umehluko phakathi kwerabha ye-EPDM ne-PVC?

Iklayenti lakho libuza "ngerabha" evalvini. Kulula ukudideka phakathi kwepulasitiki eqinile yomzimba wevalvini nezinto eziguquguqukayo ezisetshenziselwa izivalo ezingaphakathi kwayo.

Ziyizinto ezihluke ngokuphelele zemisebenzi ehlukene. I-PVC iyi-thermoplastic eqinile esetshenziselwa ukwenza umzimba we-valve kanye nebhola. I-EPDM iyirabha yokwenziwa eguquguqukayo esetshenziselwa ukwenza ama-O-rings kanye nezihlalo ezidala uphawu.

Lokhu kuyiphuzu lokudideka okuvamile. Ake sikwenze kube lula kakhulu. Cabanga ngevalvu njengomnyango. I-PVC iwuhlaka lomnyango oluqinile noluqinile kanye nomnyango ngokwawo. Ihlinzeka ngesakhiwo namandla. I-EPDM iwukukhumula kwerabha okuguquguqukayo okuvala uhlaka. Uma uvala umnyango, ukukhumula kwesimo sezulu kuyacindezela ukuze kudalwe uphawu oluphelele, olungangeni manzi. Awukwazi ukwenza umnyango ngokukhumula kwesimo sezulu, futhi awukwazi ukwenza uphawu oluguquguqukayo ngohlaka lomnyango oluqinile. Kumavalvu ethu, i-PVC inikeza indawo yokubopha engacindezeleki. I-EPDM inikeza izingxenye ezithambile neziguquguqukayo ngaphakathi ezivimba ukugeleza kwamanzi. Ayikho into efana nophawu “lwerabha lwe-PVC” kula mavalvu; izivalo ziyinto ehlukile, ekhethekile.

Uyini umehluko phakathi kwe-EPDM ne-NBR 70?

Ubheka ishidi lokucacisa bese ubona i-“NBR 70″. Uyazi ukuthi i-NBR iyini, kodwa awuqiniseki ukuthi inombolo ethi “70″ isho ukuthini noma ukuthi iqhathaniswa kanjani ne-EPDM.

I-“70″ ku-NBR 70 ibhekisela ku-durometer yayo, noma isilinganiso sobulukhuni. Ibonisa ukuthi irabha ilukhuni kangakanani. Kokubili i-EPDM ne-NBR kuza ngobunzima obuhlukahlukene, kanti i-70 Shore A iyindinganiso evamile.

Inombolo ayiyona ingxenye yohlobo lwezinto ezibonakalayo; iyisilinganiso sezakhiwo zayo ezibonakalayo. Ukuqina kwerabha ezithambile kulinganiswa ku-“Ugu A"isikali." I-durometer engu-70 iwubulukhuni obuvamile kakhulu, obuphakathi nomgwaqo. Iqinile ngokwanele ukumelana nokusunduzwa endaweni yayo ngaphansi kwengcindezi kodwa isaguquguquka ngokwanele ukudala uphawu oluhle. Ungathola i-NBR 50 (ethambile) noma i-NBR 90 (enzima kakhulu). Okufanayo kusebenza ku-EPDM; ungaba ne-EPDM 70 futhi. Ngakho-ke, ukuqhathanisa kwangempela kuhlala kuphakathi kwezinto eziyisisekelo—I-EPDM vs. i-NBRInombolo yobunzima ikutshela ukuthi ifanele yini ingcindezi yesistimu yakho. Eziningi zezinhlelo zokusebenza ezijwayelekile zamanzi nomoya, uphawu lwe-durometer lwama-70 lunikeza ibhalansi ephelele yokusebenza nokuqina.

Iyini izinga lokushisa le-EPDM uma liqhathaniswa ne-NBR?

Udinga ukukhetha ivalvu yesistimu engase ishise kakhulu elangeni noma ibande kakhulu ebusika. Ukukhetha isivalo esingakwazi ukusingatha izinga lokushisa kuzokwenza ukuthi iqhekeke futhi ivuza.

I-EPDM inobubanzi obuphezulu bokushisa, ngokuvamile kusukela ku--50°C kuya ku-150°C (-58°F kuya ku-302°F). I-NBR inobubanzi obulinganiselwe, ngokuvamile kusukela ku--40°C kuya ku-120°C (-40°F kuya ku-248°F).

Ukusebenza kwezinga lokushisa kuyisizathu esikhulu esenza i-EPDM ibe yisinqumo esingcono kakhulu. Amandla ayo okuhlala iguquguquka emazingeni okushisa aphansi kakhulu ayenza ithembeke kakhulu ezindaweni ezibandayo. Izinga layo lokushisa eliphakeme kakhulu lisho ukuthi ingakwazi ukusingatha imigqa yamanzi ashisayo futhi cishe ayinakonakala emishinini ehlala elangeni elishisayo. I-NBR, yize ilungile, ingaba lukhuni futhi iqhekeke uma ibanda kakhulu, okungenza ukuthi ingakwazi ukuvala. Emazingeni okushisa aphezulu, ingaguga futhi iqine ngokushesha kune-EPDM. Yingakho eShayina, ama-valve amaningi ajwayelekile, ashibhile asebenzisa i-NBR, kodwa sihlala sincoma i-EPDM kunoma yiluphi uhlelo lokusebenza olubhekene nokushisa okukhulu noma oludinga ukuthembeka kwesikhathi eside.

Ukuqhathanisa Okusheshayo Kwezinto Zokuvala

Isiphetho

Uma ufuna amanzi, isimo sezulu, kanye nokushisa okuphezulu, khetha i-EPDM. Uma ufuna amafutha kanye nophethiloli, khetha i-NBR. Ukuqondanisa uphawu nohlelo lokusebenza kuyimfihlo yevalvu ye-PVC ethembekile, ehlala isikhathi eside, engavuzi.