Question 33 1AE01 - First Assistant Engineer

The Correct Answer is B **Explanation of Option B (Metered-Out Circuit):** A metered-out circuit controls the speed of an actuator (like a cylinder) by placing a flow control device (typically an adjustable orifice or flow control valve) in the exhaust or return line *from* the actuator. In the illustrated circuit (GS-0106), if the flow control valve is positioned between the cylinder port and the return tank (controlling the fluid leaving the cylinder), it acts as a restriction that governs how fast the cylinder can retract or extend by limiting the flow rate of the oil exiting the cylinder. This type of circuit is highly effective for controlling resistive loads (loads opposing the cylinder motion) and preventing a load from running away, as pressure is maintained on the load side of the cylinder. **Explanation of Incorrect Options:** * **A) Metered-In Circuit:** This circuit places the flow control valve in the line leading *to* the actuator (the inlet line). While effective for resistive loads, it is generally less stable than a metered-out circuit when dealing with overrunning or negative loads, and it is not the configuration shown if the valve is located on the exhaust side. * **C) Bleed-In Circuit:** This term is not standard nomenclature for hydraulic speed control methods. The common term involving "bleed" is "bleed-off." * **D) Bleed-Off Circuit:** Also known as a bypass circuit, this configuration uses a flow control valve placed in a line parallel to the actuator (a bypass line). This valve bleeds off or diverts excess pump flow directly back to the tank, thereby controlling the flow available to the actuator. This is distinct from restricting the exhaust flow, which is characteristic of the metered-out circuit.