The improvement of the structure design of control valves using the contemporary methods of computational gas dynamics (CFD) requires the verification of used mathematical model, which is the top-priority problem. This scientific paper gives the comparison of the data of numerical investigation of the flow motion in the Venturi-type control valve in the high pressure section of the turbine К-300-240 with full-scale test data. A satisfactory agreement with experimental data with regard to the value of the reduced flow coefficient and the pressure distribution along the bypass of valve seat and valve cup has been shown. A relative error of the definition of reduced flow is within 10,2 % and for the average integral pressure distribution along the bypasses of valve seat and valve cup for all modes it is equal to 5 %. It has also been shown that the solution of problem in the axial symmetry statement gives an opportunity to significantly reduce the scope of computations, but it fails to provide an opportunity for taking into account in full the nonstationary effect of flow on actuated valve parts.