What characterizes a closed-center hydraulic circuit?

What characterizes a closed-center hydraulic circuit?

• A. It allows continuous flow to the reservoir when idle.
• B. It keeps the main line pressurized and blocks flow to the reservoir when idle.
• C. It supplies constant maximum flow to the actuator.
• D. It uses gravity to drain fluid when idle.

Answer: (B)

Closed-center circuits keep the main hydraulic line pressurized when there’s no demand, and the control valve blocks flow back to the reservoir. This means the pump is still circulating fluid, but it isn’t allowed to return to tank, so the line stays charged and there’s no idle flow. Only when a command opens the circuit does fluid move to the actuator and then return through the system. This setup reduces wasted energy and heat from pumping fluid that just circulates at idle, and it often uses a pressure-controlled pump to hold that pressure with minimal flow. This differs from an arrangement that allows continuous flow to the reservoir when idle (that would be open-center), and it isn’t about sending a constant maximum flow to the actuator or relying on gravity to drain fluid.

Closed-center circuits keep the main hydraulic line pressurized when there’s no demand, and the control valve blocks flow back to the reservoir. This means the pump is still circulating fluid, but it isn’t allowed to return to tank, so the line stays charged and there’s no idle flow. Only when a command opens the circuit does fluid move to the actuator and then return through the system. This setup reduces wasted energy and heat from pumping fluid that just circulates at idle, and it often uses a pressure-controlled pump to hold that pressure with minimal flow.

This differs from an arrangement that allows continuous flow to the reservoir when idle (that would be open-center), and it isn’t about sending a constant maximum flow to the actuator or relying on gravity to drain fluid.