Polytetrafluoroethylene(Teflon ko PTFE), wanda aka fi sani da "sarkin filastik", wani sinadari ne na polymer da aka yi da tetrafluoroethylene ta hanyar polymerization, tare da kyakkyawan kwanciyar hankali na sinadarai, juriya ga tsatsa, hatimi, rashin man shafawa mai yawa, rufin lantarki da kuma juriya mai kyau wajen hana tsufa.

PTFE yana da sauƙin shiga cikin sanyi kuma yana ratsawa ƙarƙashin matsin lamba da zafin jiki mai yawa, don haka gabaɗaya ana amfani da shi don ƙarancin matsin lamba, matsakaicin zafin jiki, tsatsa mai ƙarfi kuma baya barin gurɓatar yanayin zafi, kamar ƙarfi mai ƙarfi, alkali, halogen, magani da sauransu. Zafin aiki mai aminci shine 150℃ kuma matsin yana ƙasa da 1MPa. Ƙarfin PTFE da aka cika zai ƙaru, amma zafin amfani ba zai iya wuce 200℃ ba, in ba haka ba juriyar tsatsa zai ragu. Matsakaicin matsin amfani na marufin PTFE gabaɗaya bai wuce 2MPa ba.

Saboda ƙaruwar zafin jiki, kayan za su yi rarrafe, wanda hakan zai haifar da raguwar matsin lamba a hatimi sosai. Ko da zafin ya dace, tare da tsawaita lokaci, matsin lamba na saman hatimin zai ragu, wanda zai haifar da "alamar sassaucin damuwa". Wannan lamari zai faru a cikin kowane irin gaskets, amma sassauta damuwa na PTFE pad ya fi tsanani, kuma ya kamata a yi taka tsantsan.

Ma'aunin gogayya na PTFE ƙanƙanta ne (matsin matsin lamba ya fi 4MPa girma, ma'aunin gogayya shine 0.035~0.04), kuma gasket ɗin yana da sauƙin zamewa waje lokacin da ake matse shi kafin a matse shi, don haka ya fi kyau a yi amfani da saman flange mai kauri da mai kauri. Idan an yi amfani da flange mai faɗi, ana iya taɓa diamita na waje na gasket ɗin tare da ƙulli don hana gasket ɗin zamewa a waje.

Saboda kayan aikin rufin gilashi suna yin tsatsa bayan fesa wani Layer na enamel a saman ƙarfe, layin gilashi yana da rauni sosai, tare da fesawa mara daidaituwa da kwararar Layer na glaze, madaidaicin saman flange ɗin ba shi da kyau. Gasket ɗin haɗin ƙarfe yana da sauƙin lalata layin glaze, don haka ana ba da shawarar amfani da kayan da aka yi da allon asbestos da marufi na roba PTFE. Marufi yana da sauƙin dacewa da saman flange kuma yana da juriya ga tsatsa, kuma tasirin amfani yana da kyau.

Akwai masana'antu da yawa a cikin zafin jiki, matsin lamba ba shi da yawa a cikin ƙarfin lalata mai ƙarfi, amfani da bel ɗin roba na asbestos na PTFE, don ramukan magudanar ruwa da aka wargaza sau da yawa. Saboda samarwa da amfani suna da matukar dacewa, suna da farin jini.