A significant amount of today's aerial devices, boom lifts, and utility trucks utilize electro-hydraulic proportional valves to control the direction and speed of many of their boom functions. By using proportional valves on these applications, it provides the operator with the ability to operate each function at high speed to move the platform close to his work quickly, or to meter flow slowly to allow him to inch his way closer without damaging structural members on the machine, or damaging the intended work area.
Most of the electro-hydraulic proportional control valves on the market today, were designed with relatively high speed or high flow rates in mind. Since a large quantity of these types of machines have one or more “low flow” function requirements, the higher flow proportional valve automatically adds cost, weight and complexity to an otherwise simple application.
To address this problem, a “Low Flow” direct acting electro-hydraulic proportional valve that offers the same individual spool pressure compensation as that of the higher-flow valves with less parts, smaller package sizes, and
This report compares the traditional higher flow pilot operated proportional valve designs with the newer, lower flow, direct actuated proportional valve and shows how they can be used together in application to benefit the end user.