8. Ukuze uvikele ukulimala kwemishini okubangelwa ukulayisha ngokweqile, kukhona i-valve yokulayisha ephezulu kakhulu kudivayisi ye-hydraulic. Lapho into edonswayo idlula umthwalo olinganiselwe, i-valve elayishwe ngokweqile izokwehlisa ngokuzenzakalelayo, futhi i-hydraulic ehlanganisiwe ye-hydraulic ene-tonnage enkulu isetshenziswa esikhundleni salokho.