A hydraulic accumulator is a pressure vessel that performs several critical functions within a hydraulic system. It is used to maintain system pressure, store and recover energy, reduce pressure spikes, support power chassis suspensions, and minimize shock, vibration, and pulsations.

Under gas pressure, accumulators store a volume of hydraulic fluid that can be fed back into the system when required. As pressure in the hydraulic system increases, the accumulator collects the pressurized fluid, resulting in the compression of the gas. When system pressure drops, the compressed gas expands and forces the stored fluid back into the hydraulic circuit.