A semi-empirical model has been elaborated for analyzing and predicting the flow characteristics
of small electro-pneumatic (EP) valves within a wide range of pressure ratio. As a
basis for characterization of flow coefficient, an analytical model has been established
for a simplified geometry. This model has been corrected corresponding to more complex
valve geometries, utilizing the results of axisymmetric quasi-3D (Q3D) computations
using the Computational Fluid Dynamics (CFD) code FLUENT. By this means, a semi-empirical
modelling methodology has been elaborated for characterization of through-flow behavior
of pneumatic valves of various geometries.