How many ports and positions does a standard 4/3-way directional control valve have?

How many ports and positions does a standard 4/3-way directional control valve have?

• A. 4 ports and 3 positions
• B. 3 ports and 4 positions
• C. 4 ports and 2 positions
• D. 5 ports and 3 positions

Answer: (A)

In valve notation, a 4/3 designation means four ports and three positions. The four ports are P (pressure supply), T (tank or return), and two work ports to the actuator, usually labeled A and B. The three positions refer to the distinct spool alignments: in one side position P connects to A (with B to T), in the other side position P connects to B (with A to T), and the center position is a neutral state where the flow paths are arranged so that neither A nor B is connected to P (often a closed-center or other center configuration). This setup allows a double-acting cylinder to extend or retract depending on the side to which the valve is shifted, with a neutral center in between.