Selected hydraulic test results of cylindrical and conical vortex valves in a pilot-plant scale are presented to discuss the effects of the geometric parameters and the spatial orientation of a vortex chamber. Tests performed include the effects of the inlet and outlet diameters, swirl radius, chamber height, and diameter on the hydraulic characteristics. A novel, universal variable K, describing the geometry of vortex valves and grouping their geometrical parameters, is introduced. This constant K increases the quantitative accuracy of the relationship between the discharge coefficient and the geometrical parameters. A test methodology for hydrodynamic vortex regulators has been developed and was applied to environmental engineering, based on dimensional analysis. This research presents the empirical equations enabling to predict the discharge coefficient according to the geometrical parameters of the devices. The investigated relationships allow for a rational parameter selection for hydrodynamic vortex regulators.