Which statement best describes a bladder-type accumulator?

• A. It consists of a shell with a flexible bladder inside the shell.
• B. It is constructed in two halves with a diaphragm barrier.
• C. It is a fully enclosed vertical cylinder with nitrogen gas.
• D. It uses a piston barrier between hydraulic oil and gas.

Answer: (A)

Bladder-type accumulators store energy by placing a flexible bladder inside a rigid shell to keep hydraulic oil separate from the pressurized gas. The gas side, usually charged with nitrogen, compresses as fluid enters the bladder, and expands to push fluid back when pressure drops. This setup allows smooth pressure delivery and pulsation damping while preventing mixing of oil and gas. Other designs use a diaphragm or a piston barrier, or rely on a simple gas chamber without a bladder, so the description of a shell with a flexible bladder inside exactly matches this type.