valukanalite süsteemi osa gaaside ärajuhtimiseks vormiõõnsusest ja vormi täitumise kontrollimiseks mis võib samaaegselt toita valandit sulametalliga, an element of the gating system which is designed to provide a connection between the mold cavity and the atmosphere, which fills with metal during pouring, thus facilitating the escape of gases, the rising of slag, and revealing the level of metal in the mold