In a closed-center hydraulic circuit, how is actuator movement energy typically delivered?

• A. The pump continuously pushes flow regardless of demand
• B. The directional valve blocks flow to the reservoir and holds pressure until commanded
• C. The flow is diverted to a separate cooling loop
• D. The actuator is powered by gravity

Answer: (B)

In a closed-center circuit, energy for actuator motion is stored as hydraulic pressure and released on demand. The directional valve, when in its neutral holding position, blocks flow back to the reservoir, so the pump pressurizes the line and maintains pressure on the actuator side. When motion is commanded, the valve shifts to connect the high-pressure line to the actuator and provide a path back to tank, letting the stored pressure push the actuator. This on-demand, pressure-driven delivery is efficient and ensures movement only when asked. The other ideas don’t fit: continuous flow regardless of demand wastes energy, diverting flow to a cooling loop doesn’t move the actuator, and gravity isn’t a reliable power source for hydraulic actuation.