What Is a Hydraulic Accumulator and How Does It Work?
A hydraulic accumulator is a device that stores energy by holding hydraulic fluid under pressure against a compressed gas charge, usually nitrogen. When system pressure rises, fluid enters the accumulator and compresses the gas; when pressure drops, the gas pushes the fluid back out. That stored energy lets an accumulator smooth pressure spikes, dampen shock and pulsation, supply backup power, and stabilize a hydraulic system.
How a hydraulic accumulator works
A hydraulic accumulator works by separating a nitrogen gas charge from the hydraulic fluid with a bladder, piston or diaphragm. As fluid is forced in, the nitrogen compresses and stores energy; when demand rises or pressure falls, the nitrogen expands and pushes the fluid back into the system. This store-and-release cycle happens almost instantly, which is what makes accumulators so useful.
What a hydraulic accumulator is used for
Accumulators do several jobs in a hydraulic system, often more than one at once:
● Energy storage and emergency / backup power
● Shock absorption and pulsation dampening
● Maintaining pressure and compensating for leakage
● Supplementing pump flow for short, high-demand cycles
● Stabilizing performance and protecting components
Types of hydraulic accumulators
There are three main types: bladder, piston and diaphragm. Bladder units respond fast and suit shock and pulsation dampening; piston units handle high flow, large volumes and high pressure; diaphragm units are compact and suit small circuits and instrumentation. See our bladder, piston and diaphragm accumulator pages for detail.
Why pre-charge matters
Every accumulator relies on a correct nitrogen pre-charge — the gas pressure with no fluid in the unit. If the pre-charge is wrong or lost, the accumulator won’t perform and can fail early, so it needs occasional checking and recharging. See accumulator nitrogen charging.
Need an accumulator supplied or serviced?
Northland is Edmonton’s hydraulic accumulator specialist — we supply, repair, charge, test and size accumulators for industrial and mobile equipment across Alberta. Talk to a specialist or call 780-466-1172.
Frequently Asked Questions
-
It’s a device that stores hydraulic energy using compressed nitrogen, then releases it to smooth pressure, absorb shock, or provide backup power in a hydraulic system.
-
Fluid entering the accumulator compresses a nitrogen charge; when system pressure drops, the nitrogen expands and pushes the fluid back into the system — storing and releasing energy on demand.
-
Bladder, piston and diaphragm — they differ in how they separate gas from fluid and in the flow, volume and pressure they suit.
-
Energy storage, shock absorption, pulsation dampening, emergency/backup power and pressure stabilization across industrial and mobile hydraulic systems.