A hydraulic accumulator is a pressure vessel that performs many tasks in the hydraulic system. They are used to maintain pressure, store and recapture energy, reduce pressure peaks, power chassis suspensions and reduce shock, vibration, and pulsations.
Under gas pressure, accumulators store a volume of fluid that can be fed back into the hydraulic system when needed. With an increase in pressure in the hydraulic system, the hydraulic accumulator collects the pressure fluid. The result: The gas is compressed. If the pressure drops, the compressed gas expands again and forces the stored fluid into the hydraulic circuit.