Which method turns a 4/2 hydraulic DCV into a 3/2 DCV?

• A. Changing the spool
• B. Blocking a port
• C. Placing the spring on the other end
• D. Changing the operator

Answer: (B)

The important idea is the meaning of the numbers in a directional control valve. A 4/2 valve has four ports (two for the active paths to the actuator plus supply and return) and two positions. A 3/2 valve has three ports (one active path plus supply and return) and two positions. To turn a 4/2 into a 3/2, you must remove or block one of its ports so the valve can no longer provide two separate paths to the actuator. Blocking a port physically caps that passage, leaving only three usable ports and effectively converting the valve’s configuration to 3/2. The other adjustments—changing the spool, swapping the spring position, or altering the operator—do not reduce the port count; they change flow paths or actuation but not the basic number of ports.