How can a 4/2 DCV effectively be made into a 3/2 DCV?

How can a 4/2 DCV effectively be made into a 3/2 DCV?

• A. Block the tank return port
• B. Connect the pump directly to outlet port A
• C. Block the tank return port and connect the pump directly to outlet port A
• D. None of the above

Answer: (A)

Blocking the tank return port is the way to make a 4/2 DCV behave like a 3/2. A 4/2 valve has a pressure port, two actuator ports, and a tank/return port. In operation, flow is alternately routed from the pressurized supply to one actuator port while the other side is connected to the tank, and then the roles swap. If you cap or block the tank return port, that return path is eliminated in both positions. You’re left with a single active flow path from the pump to the actuator, with no path back to tank, which effectively mirrors the way a 3/2 valve operates (pressure to the actuator in one position, and no return path in the other). The other options would bypass the valve or leave a return path that doesn’t replicate a true 3/2 behavior.

Blocking the tank return port is the way to make a 4/2 DCV behave like a 3/2. A 4/2 valve has a pressure port, two actuator ports, and a tank/return port. In operation, flow is alternately routed from the pressurized supply to one actuator port while the other side is connected to the tank, and then the roles swap. If you cap or block the tank return port, that return path is eliminated in both positions. You’re left with a single active flow path from the pump to the actuator, with no path back to tank, which effectively mirrors the way a 3/2 valve operates (pressure to the actuator in one position, and no return path in the other). The other options would bypass the valve or leave a return path that doesn’t replicate a true 3/2 behavior.