Unobangela wokungaphumeleli kokuphuka emva kweenyanga ezili-18 zevalve yentsimbi engenasiphene isebenze iinyanga ezili-18, kwaye ivalve yokwaphuka yabhaqwa yaza yahlalutywa ivalve yokwaphuka, izicubu zesigaba segolide, kunye nokwakheka kweekhemikhali. Iziphumo zibonisa ukuba indawo eqhekekileyo yevalve liqokobhe kwaye into yokucoca iphinda iphonononge indawo, oko kukuthi, ukumelana neyona ndawo inkulu yoxinzelelo lwerhasi, umthombo wokhukuliseko kunye nomthombo wokuqhekeka ovela kwingcambu yomsonto ongaphakathi, owandisiweyo ukuya kumphezulu weqokobhe levalve ukuya ngaphandle. Ngaphantsi kwevalve umzimba owaphukileyo umlomo usicaba, kwaye iintanda phakathi kweenkozo ziphelele, zibonisa iimpawu zamaqhekeza akrispy. Kukho ukutenxa okukhulu kumxholo we-CR kunye ne-Ni kwisakhiwo somzimba wevalve yokucoca, kunye nomxholo we-ferrite mkhulu kune-10%, okunciphisa ukuqina kweplastiki yezinto. Lo ngumba wendalo ekusilela kwezinto; Ukhukuliseko luxutywe kunye nesigaba sesibini se-carbon-rich kunye ne-chromium ekubuyiseleni izinto eziphathekayo, kunye nokuqhekeka kwindawo apho ugxininiso loxinzelelo lugxininiswe. Ngaphantsi kwempembelelo yoxinzelelo olutshintshileyo, ukuqhekeka kwandiswa ngakumbi, kwaye izinto ziya kuphuka ekugqibeleni.