Mpweya wotetezera mpweya
Valavu yam'mlengalenga momwe kutentha kogwirira ntchito sikutsika 200 ℃, ndi mpweya wa kompresa wokhazikika pachitetezo pakapanikizika kwa zida zopitilira mtengo wololedwa, valavu itseguka yokha ndikutsitsa kukakamizika kwathunthu. Mphamvu ikamatsika pamtengo womwe wanenedwa. Valavu imazimitsa zokha, kuti zida ziziyenda bwino.
