Thupi la valavu iyi ndiye gawo lalikulu la mavalavu owongolera omwe ali ndi mphamvu yokakamiza m'mapayipi a mafakitale. Yopangidwa ndi chitsulo chapamwamba kwambiri, imakhala ndi mphamvu zambiri ndipo ndi yoyenera kugwiritsidwa ntchito kutentha kwambiri, kuthamanga kwambiri komanso kutsegula ndi kutseka pafupipafupi. Imapezeka nthawi zambiri pomanga mavalavu a mpira, mavalavu ozungulira ndi mavalavu owongolera m'mafakitale monga mafuta, gasi wachilengedwe, uinjiniya wa mankhwala ndi malo opangira magetsi.