Abstract: A linear sliding gate valve (10) for a metallurgical vessel comprises a slide plate (20) with a first orifice (30) and a fixed plate (22) with a second orifice (32). A slideable tray (26) supports the slide plate (20) and is arranged to slide the slide plate (20) relative to the fixed plate (22) so as to control an outflow of the metallurgical vessel by the relative position of the first and second orifices (30; 32). The slide plate (20) is rotatable relative to said slideable tray (26). The sliding gate valve further comprises a ratchet mechanism (40; 140) for providing defined angular positions of the slide plate (20). The ratchet mechanism (40; 140) is mounted on the slideable tray (26) such that the slideable tray (26) forms the fixed frame of the ratchet mechanism (40; 140).