Rabala ya mafakitale

Rabala yachilengedwe imatha kupirira zinthu monga madzi abwino, madzi amchere, mpweya, mpweya wopanda mphamvu, alkali, ndi mchere; komabe, mafuta amchere ndi zinthu zosungunulira zopanda mphamvu zimaiwononga. Imagwira ntchito bwino kwambiri kutentha kochepa ndipo imagwiritsidwa ntchito kwa nthawi yayitali osapitirira 90°C. Imagwira ntchito bwino pa -60°C. Gwiritsani ntchito chitsanzo pamwambapa.

Mafuta opangidwa ndi mafuta kuphatikizapo mafuta, mafuta odzola, ndi mafuta odzola ndi oyenera kugwiritsa ntchito mphira wa nitrile. Kutentha kogwiritsidwa ntchito kwa nthawi yayitali ndi 120°C, 150°C mu mafuta otentha, ndi -10°C mpaka -20°C kutentha kochepa.

Madzi a m'nyanja, ma asidi ofooka, ma alkali ofooka, njira zamchere, kukana bwino kwa okosijeni ndi ozoni kukalamba, kukana mafuta komwe kuli kochepa poyerekeza ndi rabara ya nitrile koma bwino kuposa rabara ina wamba, kutentha komwe kumagwiritsidwa ntchito kwa nthawi yayitali komwe kuli kotsika kuposa 90 °C, kutentha kwakukulu komwe kumagwiritsidwa ntchito komwe sikupitirira 130 °C, ndi kutentha kochepa komwe kuli pakati pa -30 ndi 50 °C zonse ndi zoyenera rabara ya chloroprene.

Rabala ya fluorine imabweramumitundu yosiyanasiyana, zonse zomwe zimakhala ndi asidi wabwino, okosijeni, mafuta, ndi zosungunulira. Kutentha kwa nthawi yayitali kumakhala kotsika kuposa 200°C, ndipo kungagwiritsidwe ntchito ndi pafupifupi zinthu zonse za asidi komanso mafuta ena ndi zosungunulira.

Pepala la rabala limagwiritsidwa ntchito kwambiri ngati gasket yolumikizira mapaipi kapena ma hole opunthidwa nthawi zambiri ndi mabowo amanja, ndipo kupanikizika sikupitirira 1.568MPa. Ma gasket a rabala ndi ofewa kwambiri komanso abwino kwambiri pakulumikizana pakati pa mitundu yonse ya ma gasket, ndipo amatha kupanga kutseka ndi mphamvu yochepa yomangika. Chifukwa cha makulidwe ake kapena kuuma kwake kochepa, gasket imafinyidwa mosavuta ikapanikizika mkati.

Mapepala a rabara amagwiritsidwa ntchito mu zinthu zosungunulira zachilengedwe monga benzene, ketone, ether, ndi zina zotero zomwe zingayambitse kulephera kwa seal chifukwa cha kutupa, kukula kwa thupi, kufewa, komanso kumamatira. Kawirikawiri, sizingagwiritsidwe ntchito ngati mulingo wa kutupa uli woposa 30%.

Ma rabara ndi abwino kwambiri pa vacuum ndi mpweya wochepa (makamaka pansi pa 0.6MPa). Rabala ndi lolemera ndipo mpweya umalowa pang'ono. Mwachitsanzo, pa zotengera za vacuum, rabara ya fluorine imagwira ntchito bwino ngati gasket yotsekera chifukwa kuchuluka kwa vacuum kumatha kufika pa 1.310-7Pa. Rabara iyenera kuphikidwa ndi kupopedwa musanagwiritse ntchito pa vacuum 10-1 mpaka 10-7Pa.

Pepala la Mphira la Asbestosi

Ngakhale kuti rabara ndi zodzaza zosiyanasiyana zawonjezedwa ku gasket, vuto lalikulu ndilakuti silingathe kutseka kwathunthu pores ang'onoang'ono omwe alipo, ndipo pali pang'ono polowera ngakhale kuti mtengo wake ndi wocheperako kuposa ma gasket ena ndipo ndi wosavuta kugwiritsa ntchito. Chifukwa chake, ngakhale kuthamanga ndi kutentha sikuli kochulukirapo, sikungagwiritsidwe ntchito pazinthu zodetsa kwambiri. Chifukwa cha carbonization ya rabara ndi zodzaza zikagwiritsidwa ntchito mu mafuta ena otentha kwambiri, nthawi zambiri kumapeto kwa kugwiritsa ntchito, mphamvu imachepa, zinthuzo zimakhala zomasuka, ndipo kulowa kumachitika pamalo olumikizirana ndi mkati mwa gasket, zomwe zimapangitsa kuti gasket iwonongeke komanso ituluke. Kuphatikiza apo, kutentha kwambiri, pepala la rabara la asbestos limamatira mosavuta pamwamba pa flange sealing, zomwe zimapangitsa kuti njira yosinthira gasket ikhale yovuta.

Kusunga mphamvu kwa gasket kumatsimikiza kupanikizika kwa gasket m'njira zosiyanasiyana zikatenthedwa. Zipangizo zokhala ndi ulusi wa asbestos zimakhala ndi madzi oundana ndi madzi oundana. Pa kutentha kopitilira 500°C, madzi oundana amayamba kugwa, ndipo mphamvu yake imakhala yotsika. Pa kutentha kopitilira 110°C, magawo awiri mwa atatu a madzi oundana pakati pa ulusiwo agwa, ndipo mphamvu yomanga ya ulusiwo yachepa ndi pafupifupi 10%. Pa kutentha kopitilira 368°C, madzi onse oundana agwa, ndipo mphamvu yomanga ya ulusiwo yachepa ndi pafupifupi 20%.

Mphamvu ya pepala la rabara la asbestos imakhudzidwa kwambiri ndi zinthu zomwe zili mkati. Mwachitsanzo, mphamvu yopingasa ya pepala la rabara la asbestos losagonja mafuta la No. 400 imasiyana pakati pa mafuta odzola a ndege ndi mafuta a ndege ndi 80%, zomwe zimachitika chifukwa chakuti kutupa kwa rabara mu pepalalo ndi mafuta a ndege kumakhala koopsa kuposa mafuta odzola a ndege. Poganizira zomwe tafotokozazi, kutentha kotetezeka kogwirira ntchito ndi kuchuluka kwa kuthamanga kwa pepala la rabara la asbestos la m'nyumba XB450 ndi 250 °C mpaka 300 °C ndi 3 3.5 MPa; kutentha kwakukulu kwa pepala la rabara la asbestos losagonja mafuta la No. 400 ndi 350 °C.

Ma ayoni a chloride ndi sulfure amapezeka mu pepala la rabara la asbestos. Ma flange achitsulo amatha kupanga batire yowononga madzi mwachangu akamayamwa madzi. Makamaka, pepala la rabara la asbestos losagwira mafuta lili ndi sulfure yochulukirapo kangapo kuposa pepala la rabara la asbestos wamba, zomwe zimapangitsa kuti lisagwiritsidwe ntchito m'malo osakhala mafuta. Mu mafuta ndi zosungunulira, gasket imatupa, koma mpaka pamlingo wina, kwenikweni siikhudza mphamvu yotsekera. Mwachitsanzo, mayeso omiza mafuta m'mlengalenga kwa maola 24 kutentha kwa chipinda amachitidwa pa pepala la rabara la asbestos losagwira mafuta la Nambala 400, ndipo akulamulidwa kuti kuwonjezeka kwa kulemera komwe kumachitika chifukwa cha kuyamwa mafuta sikuyenera kupitirira 15%.