Here is a complete line of Accumulators offerings
The bladder accumulator consists of a fluid section and a gas section, with the bladder acting as a gas-proof screen.
Eaton diaphragm accumulators utilize the compressibility of a gas (nitrogen) in storing hydraulic energy. The gas is required because fluids are practically incompressible and thus, cannot store energy by themselves.
Fluids are practically incompressible and cannot therefore store pressure energy. The compressibility of a gas (nitrogen) is utilized in hydro pneumatic accumulators for storing fluids.