Valve ea Heke ea Seretse

Li-valve tsa heke ea seretse ke heke e tiileng, kutu e ntseng e phahama, li-valve tsa heke tse nang le litiiso tse tšoarellang, li-valve tsena li entsoe ho latela maemo a API 6A. E sebelisoa haholo bakeng sa seretse, samente, ho pshatla le tšebeletso ea metsi 'me li bonolo ho li sebelisa ebile li bonolo ho li hlokomela.