Diaphragm Accumulators

Compact Energy Storage for Hydraulic Systems

Diaphragm accumulators are compact, responsive devices used to store energy, absorb shock and vibration, and compensate for fluid volume changes in hydraulic systems. Their fast reaction time and simple construction make them ideal for mobile and industrial applications where space is limited and performance is critical.

At Hydraulics Online, we supply diaphragm accumulators from a wide range of global manufacturers – including Bosch Rexroth, Hawe, Hydac, Parker, and QHP – with impartial advice to help you find the right solution for your system.

Our website shows only a selection of what we supply. For impartial advice and access to our full range of hydraulic components, contact our expert team.

diaphagm accumulators. For impartial advice and access to our full range of hydraulic components, contact our expert team.

A diaphragm accumulator consists of a high-tensile steel pressure vessel divided internally by a flexible, gas-tight diaphragm. One side of the diaphragm is pre-charged with nitrogen gas, while the other side is connected to the hydraulic circuit.

Here’s how it works:

When system pressure increases, hydraulic fluid enters the accumulator and compresses the gas.
When system pressure drops, the gas expands, pushing fluid back into the system.

This process allows the accumulator to store and release energy as needed, helping to stabilise pressure and improve system responsiveness.

Energy Storage – stores hydraulic energy for later use, reducing pump demand
Shock and Vibration Absorption – dampens pressure spikes and mechanical shocks
Leakage and Volume Compensation – maintains pressure in the event of fluid loss or thermal expansion
Emergency Power Supply – provides backup pressure in case of pump failure

These functions make diaphragm accumulators essential in mobile machinery, automation systems, and high-cycle industrial equipment.

Fast response time – ideal for systems with rapid pressure fluctuations
Compact and lightweight – perfect for space-constrained installations
High efficiency – minimal internal leakage and excellent energy recovery
Simple construction – fewer components for easier maintenance
Wide pressure range – suitable for low to medium-pressure systems

What gas is used in diaphragm accumulators? Dry nitrogen is typically used due to its inert properties and stability under pressure.

Are diaphragm accumulators suitable for mobile equipment? Yes – their compact size and fast response make them ideal for mobile and off-highway applications.

Can diaphragm accumulators be serviced or recharged? Many models allow for gas recharging, and some offer replaceable diaphragms depending on the design.