Electro/Hydraulic Cartridge Style Directional control valves are helping to meet the design objectives of increased productivity, reliability and serviceability of todays mobile equipment. These compact screw-in type 2 Way, 3 Way, and 4 Way valves are presently being used on a variety of construction equipment which include Motor Graders, Excavators, Scrapers and Front-End Loaders. They are used in pilot control circuits for shifting large valves, transmission shift controls, Hi-Low speed circuits, in addition to clutch and differential lock functions.Typically these valves are installed in a form drilled and tapped cavity which is machined into a valve housing. Solenoid cartridge valves and other valving components installed in multi-drilled bodies provide a complete self-contained hydraulic circuit. This paper describes these valves and the various applications involving the cartridge valve concept.