Question 10 3AE02 - Third Assistant Engineer (Alt)

The Correct Answer is D **Explanation for Option D (Accumulator):** An accumulator is a device designed to store hydraulic energy in the form of pressurized fluid. It typically consists of a container separated into two chambers by a piston, bladder, or diaphragm; one chamber holds hydraulic fluid, and the other holds compressed gas (usually nitrogen). When the pump is running, it pressurizes the fluid into the accumulator, compressing the gas. If the pump temporarily shuts down, or if there is a sudden demand for high flow or instantaneous force, the compressed gas expands, rapidly forcing the stored hydraulic fluid into the system. This stored energy provides an immediate source of hydraulic force even when the primary pump is inactive or unable to meet the immediate demand. **Why the other options are incorrect:** * **A) Sump actuator:** This term does not refer to a standard, discrete component used for storing energy in a hydraulic system. "Sump" refers to the fluid reservoir (tank), and an actuator is a device that converts hydraulic power into mechanical motion (like a cylinder or motor). Neither the sump nor an actuator fulfills the function of storing pressure to provide instantaneous reserve force. * **B) Pressure compensator valve:** This is a control device, often integrated into a pump, designed to adjust the pump's output flow or pressure to match the system's needs. It maintains a specific pressure setpoint but does not store pressurized fluid energy to be used when the pump is off. * **C) Modulator:** A modulator (or modulating valve) is a type of control valve used to gradually change or "modulate" flow or pressure in a system (often found in braking or transmission systems). Like the compensator, it regulates fluid behavior but does not store hydraulic energy for later use.