Tech Tips

N2 system – N2 generator HAKKO FX-780 and FX-781


Nitrogen gas is separated when the air form compressor passing through HAKKO FX-780/FX-781 and flows to N2 flowmeter HAKKO FX-791 through the tube. The other air constituents are discharged outside.

HAKKO FX-780: Small-capacity type
HAKKO FX-781: Large-capacity type, accepts 2 irons

What is the mechanism of N2 separation?

Applied for the different permeability of each air constituent. N2 has a lower permeability than oxygen or carbon dioxide does.



Air Supply Pressure
0.3Amount of Generation0.150.370.480.660.881.11.32.6
0.4Amount of Generation0.240.570.771.
0.5Amount of Generation0.350.751.
0.6Amount of Generation0.480.971.
0.7Amount of Generation0.551.


Air Supply Pressure
0.3Amount of Generation0.280.550.841.
0.4Amount of Generation0.490.
0.5Amount of Generation0.
0.6Amount of Generation0.921.
0.7Amount of Generation1.
Usage note

Connect the tube of compressor to the valve “AIR IN”. If connecting to the valve “N2 OUT”, N2 separation performance may decrease and nitrogen gas is not discharged from HAKKO FX-791.

*The picture below shows the connection sample of small-capacity type HAKKO FX-780

Required air pressure

Compressed air supply: 0.3 ~ 0.7MPa to HAKKO FX-780 or HAKKO FX-781 and 0.5MPa is recommended. If compressed air 0.2MPa or less is supplied, the performance may decrease and if 0.8MPa or more, HAKKO FX-780/FX-781 may be damaged. The followings are required to supply compressed air of 0.3 ~ 0.7MPa.

Compressor: 0.3MPa or more air pressure and 10L/min or more flow rate. Regulator: 0.3 ~ 0.7MPa gas pressure adjustment. For further information, click here.

Maintenance for compressor, air dryer and filters

Perform periodical maintenance of the above devices to keep HAKKO FX-780/FX-781 in good condition. Check and clean them periodically in accordance with the manufacture’s recommendations. Take a special notice of filter to be replaced periodically. If not, the separation performance may decrease or HAKKO FX-780/FX-781 may be damaged due to intrusion of water, dust, etc. The life time of HAKKO FX-780/FX-781 is approx. 5 years under the condition of the 8-hours a day / 240 days a year operation.

When the HAKKO FX-780 or HAKKO FX-781 end of life, the high polymer membrane needs to be replaced. As it costs as the same price as purchasing a new one, we would recommend purchasing instead of replacing.