This classification covers hydraulic accumulators that absorb pressure fluctuations in hydraulic systems and store/release energy. It includes various accumulator types such as bladder-type, piston-type, and diaphragm-type units, along with related components like charging valves, safety valves, and pressure switches. Used for rapid feed in press machines, clamping operations in injection molding machines, and auxiliary power in machine tools, these devices provide pressure stabilization, shock absorption, and emergency backup power for hydraulic circuits. Unlike hydraulic pumps or cylinders, these specialized equipment focus on pressure energy storage and release functions, contributing to improved system responsiveness and energy efficiency.