Kusebenza ohlelweni lwamafutha nowokugcoba amafutha, uwoyela ungashintshwa ngokunqumela, futhi okuthengiswayo ngakunye kuhlinzekwa nge-valve yesheke ukuvikela uwoyela wokukhishwa kwephampu ye- hlobo, ungasetshenziswa ngephampu yokuthambisa kawoyela.
