An accumulator is identified by its function, its construction and three stamped figures: gas volume, gas precharge pressure and maximum working pressure. Pilot accumulators are small bladder or piston units that hold pilot pressure for emergency lowering and for keeping functions alive at start-up; suspension accumulators are larger piston or bladder units charged to suit machine weight; cylinder-mounted units act as springs. All are charged with dry nitrogen only. Match all three figures and the port thread when ordering, and never recharge or test a suspect unit with anything other than nitrogen.
What each stamped figure means
| Stamped figure | What it decides when ordering |
|---|---|
| Gas volume (liters) | The physical size class. Must match the circuit's energy requirement; a smaller unit cannot do the job. |
| Precharge pressure | Set at the factory for the duty. Drift over time is service data, not an identity change. |
| Maximum working pressure | Never exceed. The replacement's rating must meet or beat the machine specification. |
| Construction (bladder / piston) | Follows the duty: pilot work favors bladder, suspension favors piston. |
| Port thread and gas valve | Must match the machine's plumbing and charging equipment. |
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Request a quoteFrequently asked
How do I know if an accumulator has lost its precharge?
The symptoms are behavioral: the machine loses pilot functions immediately after shutdown instead of holding them for safe lowering, ride becomes harsh on suspended machines, or shock loads hit the structure harder than before. A gauge on the gas valve with the hydraulic side discharged gives the figure directly.
Can I recharge an accumulator with compressed air?
No. Nitrogen only. Air carries moisture that condenses inside the unit and corrodes it, and air is compressible in ways that change the unit's response. The stamped precharge figure also assumes an inert gas; filling with anything else invalidates it.
Is a used accumulator safe to fit?
Only with evidence. A unit whose precharge holds steadily after recharging and whose bladder or piston shows no damage is serviceable; a unit of unknown history that will not hold its gas is a sealed guess. Precharge test results and the stamping condition decide, not the price.