Accumulator Bladder

Shanghai Siken Industries Inc.

Web: www.siken-inc.com

An accumulator bladder is the flexible, balloon-like rubber (elastomeric) membrane inside a bladder-type hydraulic accumulator.

Function

It separates the hydraulic fluid (oil) from the compressed gas (usually nitrogen) inside the accumulator shell.

• When hydraulic pressure rises, fluid enters the accumulator and compresses the gas by squeezing the bladder.

• When system pressure drops, the compressed gas expands the bladder and pushes the stored fluid back into the hydraulic circuit.

This allows the accumulator to:

• Store energy

• Smooth pressure fluctuations

• Absorb shocks and pulsations

• Provide emergency hydraulic power (e.g., in BOP/Koomey units or other systems)

Key points

• The bladder is pre-charged with nitrogen to a specific pressure.

• It is the most common type of separator used in hydraulic accumulators (others are piston or diaphragm types).

• Over time, bladders can wear, crack, or lose elasticity and need replacement.

In short: the bladder is the flexible barrier that makes a hydraulic accumulator work by allowing gas to compress and expand while keeping it separate from the oil.