Masibe ngokoqobo, lapho othile ebuza mayelana nokuqina kwe-gasket ye-PTFE, ngokuvamile ufanekisela uphawu lomlingo oluphatha u-500°F unomphela. Yindawo yokuqala lapho sikhubeka. I-PTFE yinhle, kodwa izinga lokushisa eliphezulu lihlobene, futhi ukuqina kuya ngokuthi yini oyicelayo ukuthi yenze. Ingabe ibhayisikili elishisayo eliqhubekayo? Ingabe kukhona ukuchayeka kumakhemikhali ngaphezu kokushisa? Noma ingabe i-static nje, i-flange eshisayo? Impendulo ishintsha konke.

Umbono Ongalungile Wesikhathi Esiphezulu kanye Nento Yangempela Yento

I-PTFE ehlanzekile iqala ukunyonyoba kakhulu ngaphezu kuka-400°F (cishe u-204°C). Ungathola imininingwane yedatha ethi isebenziseka kufika ku-500°F (260°C), futhi ngokobuchwepheshe, ngeke incibilike ngokushesha. Kodwa kuleyo mingcele ephezulu, izici zayo ezingokomzimba ziyathamba. I-gasket ingageleza ngokubandayo, okusho ukuthi iwohloka kancane ngaphansi komthwalo webhawodi, okuholela ekuphumuleni kwengcindezi nokuvuza ekugcineni. Ngakho, ukuqina ku-250 ° C kungumbuzo wesikhathi nokucindezela, hhayi u-yebo / cha olula.

Ngikhumbula iphrojekthi yomugqa wamakhemikhali ohlanzwa ngesitimu ngezikhathi ezithile. Izinga lokushisa lingakhuphuka libe ngu-230°C isikhathi esifushane. Sasebenzisa a I-PTFE gasket, futhi yasebenza… cishe izinyanga ezintathu. Khona-ke ukuvuza kwaqala ezimbotsheni zamabhawodi. Inkinga bekungelona izinga lokushisa eliphakeme ngese futhi, kodwa imijikelezo yokushisa ephindaphindiwe ehlanganiswe nokuzungeza kwe-flange ngesikhathi sokubhowuda. Izinto ezisetshenziswayo zaphelelwa amandla.

Kungakho amamaki e-PTFE agcwalisiwe eqala ukusebenza. Izinto ezifana ne-PTFE egcwele ingilazi noma egcwaliswe ngekhabhoni zithuthukisa ukumelana ne-creep. Angakwazi ukusingatha imithwalo ephakeme yemishini emazingeni okushisa aphakeme, anwebe impilo yesevisi. Kepha noma kunjalo, uhweba ngokunye okumsulwa kwe-PTFE's superb chemical resistance. Kuhlala kuvumelana.

Izindlela Zokuhluleka Uzifunda Ngokubona Kuphela

Ngaphansi kwezimo ezicindezelayo, umphumela omkhulu ukuwohloka kokushisa. Ukuchayeka isikhathi eside ekugcineni okuphezulu kwebanga lokushisa kubangela i-PTFE ukuthi ibe brittle. Ayincibiliki; iqala ukuqhekeka, ikakhulukazi ngesikhathi sokuvalwa lapho izinto zipholile. Uzothola i-gasket ihlakazekile ibe yizicucu lapho uvula i-flange.

Elinye iphuzu elicashile ukuqedwa kwe-flange surface. Kumasevisi wezinga lokushisa eliphezulu, isiphetho esine-serrated singacaciswa ukuze kulume kangcono. Kodwa ngezinto ezithambile ezifana ne-PTFE, lawo ma-serrations angasika ku-gasket ngokuhamba kwesikhathi, ikakhulukazi phakathi nemijikelezo yokwandisa/yokufinyela okushisayo. Ngishintshele ku-spiral-wound gasket ene-PTFE filler ezimweni ezinjalo, lapho ama-windings ensimbi athatha ukulunywa ngomshini, futhi i-PTFE inikeza uphawu. Okungcono kakhulu ukuqina.

Ingcindezi enye ingxenye yesibalo. Ulayini onezinga lokushisa eliphezulu, onengcindezi ephansi ungase uvumele i-PTFE gasket eminyakeni edlule. Lelo zinga lokushisa elifanayo elinomfutho ophakeme wangaphakathi, ikakhulukazi uma lijikeleza, lizofinyeza kakhulu impilo yalo. Umthwalo ebusweni be-gasket ushintsha njalo, usebenza impahla.

Izingibe Zokukhetha Okusebenzayo Nokufakwa

Ubukhulu be-gasket bubaluleke kakhulu kunalokho abantu abakucabangayo. Kuzinhlelo zokusebenza zezinga eliphezulu, ngivame ukuncipha. I-gasket engu-1.5mm inezinto ezincane ezingakhasa futhi zihlanekezelwe kune-3mm eyodwa. Kudinga futhi ukulayishwa kwebhawodi okuphezulu ukuze kuvalwe ekuqaleni, okuholela esicini esilandelayo esibalulekile: inqubo yokubhowula.

Uma ungatholi umthwalo webhawodi zisuka nje, khohlwa isikhathi eside izinga lokushisa eliphezulu ukusebenza. I-Under-torquing, futhi uphawu lokuqala alulungile. Ukusebenzisa ngokweqile, futhi ucindezele i-PTFE ngaphezu kokululama, ukusheshisa ukukhasa. Ukusebenzisa i-torque wrench elinganisiwe kanye nokulandelana kokuqinisa kwephethini ephambanayo akuwona nje umkhuba omuhle; umehluko phakathi kwe-gasket ehlala unyaka owodwa noma emithathu.

Lokhu sikufunde kanzima ebhange lezishintshi zokushisa. Ithimba labalungisayo lisebenzise izikrufu zokuthinta isivinini. Ama-gaskets (uhlobo lwe-PTFE oluqinisiwe) aphephule kungakapheli amasonto efinyelele izinga lokushisa lokusebenza. Umthwalo ongalingani, owedlulele udale amaphuzu engcindezi asendaweni lapho ukushisa kuphelile.

Isetshenziswa Nini Futhi Nini Ukuhamba

Ngakho-ke, ingabe i-gasket ye-PTFE ephakeme kakhulu yenza umqondo kuphi? Ngesevisi eqhubekayo, ngizoqaphela ngaphezu kuka-200°C ngaphandle uma kuyibanga eligcwele futhi ingcindezi iphansi. Indawo yayo emnandi isenkonzweni ebolayo lapho izinga lokushisa lilinganiselwe kodwa amakhemikhali akhipha ama-elastomer amaningi. Isibonelo, imifudlana ye-asidi eshisayo ku-150-180 ° C.

Ukuze uthole izinga lokushisa eliphezulu langempela, ama-flange anengcindezi ephezulu, njengasekuphehlisweni kwamandla, ubheka ama-graphite, amanxeba okuvunguza, noma amalunga ohlobo lwendandatho. I-PTFE akuyena umdlali lapho. Ngibone imininingwane evela kumafemu onjiniyela abiza i-PTFE ngokungaboni ukuthi angagqwala kulayini ongu-280°C, futhi iyindlela yokuvalwa. Kufanele uhlehle ngemikhawulo yezinto ezibonakalayo.

Ngezinye izikhathi, isixazululo sigqitshwa. Iphrojekthi engisebenze ngayo nomhlinzeki ofana I-Handan Zitai Fetesser Comment Co, Ltd. (bazinze e-Yongnian, ihabhu elikhulu lokubopha e-Hebei, ungabathola e- zitasteners.com) akubandakanyi nje i-gasket kuphela kodwa lonke uhlelo lokubhowula. Sasidinga amabhawodi anamandla amakhulu akwazi ukugcina umthwalo ekushiseni ukuze kugcinwe i-gasket ye-PTFE isebenza. Iwuhlelo, hhayi ingxenye eyodwa.

Ukubuka Kwesikhathi Eside Nezinye Ezihlukile

Ukuqina ekugcineni kumayelana nezindleko eziphelele. I-PTFE gasket eshibhile ehlulekayo ezinyangeni eziyisi-6 ibiza kakhulu emsebenzini kanye nesikhathi sokuphumula kune-spiral-wound gasket ebiza kakhulu ehlala iminyaka emi-5. Udinga ukubheka ishejuli yesondlo kanye nokubaluleke kakhulu komugqa.

Ngokushintshwa kwama-flange akhona, hlala ukala igebe kuzinga lokushisa lokusebenza uma ukwazi. Ama-flange amadala ajika. I-gasket oyifakayo ebandayo kufanele ivaleke ngokushisa, ku-geometry ehlanekezelwe. Ngezinye izikhathi, inketho eqinile kakhulu ukulungisa i-flange kuqala.

Ekugcineni, ukuphendula kukuphoqa ukuthi ubuze eminye imibuzo eyishumi nambili. Ithini iphrofayili yezinga lokushisa eliqondile? Iyini i-medium? Siyini isimo se-flange nokubopha? Ayikho impendulo eyodwa, isethi nje yokuhwebelana esekelwe kokuhlangenwe nakho—futhi ngezinye izikhathi, ekuhlulekeni kwangaphambilini. Umgomo awukona unomphela; eyesikhawu sesevisi esibikezelwayo, esithembekile ongakwazi ukusihlela ngaso. Futhi ngalokho, ukuqonda imikhawulo yomhlaba wangempela wezinto ezibonakalayo ukuphela kwento esebenzayo.