The Hydraulic switching control systems could have a significant higher performance in contrast to the convectional systems which operate based on the flow throttling such as servo or proportional valves. The goal of the present work is to design and build a switching valve which has the least possible power dissipation and controls the output flow by means of continuous on/off with a proper frequency. The mission is fulfilled by cutting the flow by a rotating disk into two main quotas: one goes directly to the tank and the other to the actuator, placed at the end of the pressure line. To calculate the efficiency of the system, a mathematical model is presented including the following power dissipation sources: throttling losses in some of the valve states, leakages, fluid compressibility and viscous friction acting on the rotating disk. Geometrical parameters of the valve are directly affecting the losses, so they're to be optimized before the manufacturing and testing processes. The results of the analyses prove the performance of the proposed valves is increased compared to throttling methods. Also the flow versus duty cycle diagram presents an almost linear behavior which is the desired one. The current solution has no dead region, in contrary to the positive overlap proportional valves. Key words: digital hydraulics, performance increase, digital valve, fast on/off valve, switching valve, rotary valve