How to Charge HYDAC Hydro-pneumatic Diaphragm Accumulators

Hydro-pneumatic accumulators need to be pre-charged with an inert gas in order to work at all. Selection of the correct gas pressure is vital, as it defines the stored hydraulic fluid volume and pressure, which are important for the safe and correct operation of any machine. It is important that the correct gas pressure is maintained, and periodic inspection is therefore necessary.

This gas used in hydro-pneumatic accumulators is almost always industrial grade nitrogen. The use of other gasses in these applications is dangerous, and should not be considered.

The nitrogen pre-charge pressure of an accumulator can only be assessed when it has been fully de-pressurised of hydraulic fluid.

This means that the accumulator must be positively isolated from a live system and released of all hydraulic energy, or that the entire system has been completely shut-down and fully de-pressurised, or that the accumulator is not currently connected to a system, for example, it is on a work bench.

The HYDAC FPU-1 Universal charging and testing unit can be fitted directly to HYDAC diaphragm and piston accumulators.
The accumulator gas valve will be opened and re-sealed by operating a hex key in a socket head cap screw, and during the charging process, it will be operated by the main spindle of the charge head.

Use only the correct equipment, that is the universal charging and testing unit, and follow this process.

HYDAC Australia host regular training courses on many topics, including hydraulic accumulator technology in Melbourne, Australia. For more information, please visit our website, www.hydac.com.au.

Important:

The purpose of this video is to give you some guidance of how to charge an hydro-pneumatic accumulator. Note that only people with special technical training should undertake this task.