What is the function of a hydraulic accumulator?

• A. To cool hydraulic fluid.
• B. To store hydraulic energy and smooth out pressure fluctuations.
• C. To measure pressure.
• D. To remove contaminants from fluid.

Answer: (B)

Hydraulic accumulators act as energy storage and pressure buffering devices. They have a gas-charged chamber (in bladder, piston, or diaphragm type) that stores hydraulic energy as fluid pressurizes the gas side. When system pressure rises above the set point, the gas compresses and stores energy; when demand suddenly increases or pressure tends to drop, the stored fluid is released to maintain a steady pressure and provide instant flow. This smooths out pump pulsations, reduces pump cycling, and helps protect components from pressure spikes, while also compensating for small leaks and temperature-related volume changes. They aren’t used to cool fluid, measure pressure, or remove contaminants—those functions come from heat exchangers, gauges, and filters, respectively.