A one-stage direction and flow control valve was studied theoretically and experimentally. A direction and flow control valve maintains a constant flow rate by changing the spool-orifice area under the variation of valve pressure drop, since the spool-orifice area is varied by the action of flowforce on the spool. A direction and flow control valve has the advantage of simple and lowcost structure compared to a conventional flow control valve utilizing a pressure regulating spool which regulates the pressure drop caused by flow through the metering orifice. The static and dynamic characteristics of a one-stage direction and flow control valve was analyzed and design data are presented. Experimental results on the flow control characteristics of the manufactured valve show satisfactory agreement with simulation results. Simulation and experimental study on the static flow characteristics of a two-stage direction and flow control vlave was also presented.
