Mostly, the total cost of pneumatic control system depends on the cost of valves because of its complex construction. The purpose of this study is to develop a small-sized and low-cost control valve. In the previous study, the low-cost wearable servo valve using buckled tube driven by a RC servo motor were proposed and tested. The relation between the motor rotational angle and the output flow rate of the valve was also investigated. In this paper, the analytical model of the valve was proposed and tested. The system parameters were also identified. The experimental result and calculated result using the proposed model and identified parameters about static flowrate characteristics were compared. As a result, the calculated results agree well with experimental results. It can be concluded that the calculated result using the model can predict well the behavior of the pressure change of the valve.