In a 5/2 or 5/3 pneumatic valve, what do the numbers indicate?

• A. Diameter and Material
• B. Number of Ports and Number of Positions
• C. Weight and Length
• D. Voltage and Current Rating

Answer: (B)

In the notation for pneumatic valves, those two numbers describe the valve’s basic geometry and how it operates. The first number is the total number of ports the valve has for air flow—these include the pressure supply, the working ports to the actuator, and the exhausts. The second number tells how many distinct flow configurations (positions) the valve can hold. A 5/2 valve has five ports and two possible configurations (two states of flow). A 5/3 valve still has five ports but three possible configurations, introducing a center or neutral position. This framing helps you understand how air can be routed through the valve without getting into the specifics of diameter, material, or electrical ratings.