The use of closed center hydraulic systems on new U. S. agricultural tractors has increased significantly in recent years. Most of these tractors use variable delivery pumps, with either constant pressure or load sensitive systems.
In its new Series 10 tractors, Ford Tractor chose to develop and produce a closed center hydraulic system using fixed displacement pumps. This system is both flexible and energy conserving. It also has many of the advantages of open center hydraulic systems and can utilize some of these components.