The adjustable sliding gate orifice type 8090 uses almost the entire performance of the GS1/GS3 proven GS valve series and is suitable for precise and continuous adjustment of a defined flow. It can be adjusted and secured manually in the installed state during operation. Stops in the end positions and a high-resolution position indicator enable reproducible setting. Among other things, the orifice facilitates the hydraulic adjustment of cooling systems, e.g. when commissioning large engines in CHPs and on ships.