Recharging of Hydraulic Accumulator

A hydraulic accumulator is a pressure storage reservoir in which an incompressible hydraulic fluid is held under pressure that is applied by an external source of mechanical energy. The external source can be an engine, a spring, a raised weight, or a compressed gas.Pre-charging an Accumulator. An accumulator typically is pre-charged with dry nitrogen. Nitrogen does not react unfavorably with hydraulic oil under pressure, and since it composes nearly 78 percent of the earth's atmosphere, it is the least expensive gas that can be used safely.