Efficient Use of Directional-Control Valves in Fluid-Logic Circuits

Various types of directional-control valves have been systematically analyzed to determine the logic output functions obtained for different input-signal combinations. It was found that a surprisingly large variety of fairly complex logic functions can be obtained with a single valve. The results are summarized in five tables, which include 186 (i.e., all the significant) input-signal combinations. Several examples are presented, illustrating how the tables can be used to implement given fluid-logic functions with a minimum number of valves. It thus becomes possible to exploit the logic capacity of these valves to their fullest extent, which can result in considerable reduction in number of valves.