Diaphragm type accumulators are used for energy storage, shock and vibration absorption and leakage oil or volume compensation in hydraulic systems. They consist of a pressure-resistant tank (high-tensile steel) whose interior is split into a gas and a fluid side by an elastic diaphragm. When the operating pressure is increased, hydraulic fluid flows into the accumulator and compresses the gas until the gas pressure is identical to the fluid pressure. When the operating pressure is reduced, the gas expands again and, in this way, feeds the hydraulic system with hydraulic fluid.