To increase productivity a new concept of proportional pressure, flow and control cartridges have been developed to enhance vehicle operation at a reasonable cost. Actuators have also been developed to stroke directional valves, or piston pumps and motors.These low power consumption devices readily interface with microprocessors.Engineers have been looking for new generations of electrohydraulic valves which will increase operator performance by simplifying the operation of vehicles with automatic controls where possible plus eliminating the brute strength manual type valving to decrease operator fatigue.Maintenance has always been a severe set back to productivity. By utilizing effective yet efficient cartridge proportional valves that are designed for simplicity of use and repair, drastic savings are shown.Previous designs were bulky and very contamination sensitive. They did the job, but were both expensive and had very high maintenance levels. These new linear products are all open loop and require no LVDT feedback.