What component stores fluid under pressure and absorbs pressure surges?

• A. Reservoir
• B. Valve
• C. Pump
• D. Accumulator

Answer: (D)

In hydraulic systems, an accumulator stores fluid under pressure and absorbs pressure surges. It typically uses a gas-charged chamber (often nitrogen) separated by a bladder or piston. When fluid is pumped in, the gas is compressed, storing energy. If a sudden demand or a rapid valve closure causes a pressure spike, the compressed gas expands and damps the surge, keeping system pressure steadier and providing immediate fluid to actuators as needed. This also reduces pump cycling and protects components from shocks. A reservoir simply holds fluid, a valve controls flow, and a pump generates pressure, but none are designed to both store pressurized fluid and damp pressure spikes like an accumulator.