Reconditioning SF6-Gas

In practice, the SF6 gas used is often contaminated with air, moisture and/or tetrafluoromethane (CF4), oil or other components due to inadequate evacuation or incorrect gas handling. This is no longer a problem since DILO offers the ecological and economical alternative to disposal:

Reconditioning and reuse of your used SF6 gas instead of final disposal.

Used SF6 gas, which no longer complies with IEC 60480, can now be treated at DILO. You can send your unusable SF6 gas up to an SO2 content of 250 ppmv to DILO, where the gas is reconditioned and after separation DILO returns the same quantity of SF6 gas in new gas quality to you, safety data sheet for the reconditioned SF6 gas included.

Our customers benefit from the reconditioning of SF6 gas at DILO by:

  • Reduced costs for SF6 disposal
  • Minimised costs for new SF6 gas
  • Low transport and storage costs
  • Emission-free preparation of gas
  • Improved "carbon footprint" by reconditioning or preparation and reuse
  • Quick processing time
  • Gas purity corresponding to the quality of new gas

Thanks to the interaction between multiple DILO treatment units, even extremely poor SF6 gas qualities can be reconditioned to 99.9% purity. This not only exceeds reuse standards, but DILO Certified Gas even exceeds the relevant specifications for new gas when using in electrical equipment.

Quality levels after preparation:

Substance DILO Quality"Certified Gas" IEC 60376:2018* (New gas) ASTM D2472-15
SF6 > 99,9 Vol.%(> 99,99 wt%) > 98,5 Vol.% ≥ 99,8 wt%
H2O ≤ 8 µl/l < 200 µl/l ≤ 8 ul/l
Frost point (100 kPa) ≤ -62 °C -36 °C -62 °C
Total acidity (HF equiv.) < 0,1 µl/l < 7 µl/l ≤ 0,3 ppmw
Air < 500 µl/l < 10.000 µl/l ≤ 500 ppmw (≙ 2500 µl/l)
CF4 < 500 µl/l < 4.000 µl/l ≤ 500 ppmw (≙ 830 µl/l)
Oil mist < 1 mg/kg < 10 mg/kg
SO2 < 0,1 µl/l


The following points must be observed before dispatch to DILO:

  • The quality of the gas must be known and the SO2 value must not exceed 250 ppmV (Download check lists). If the quality is unknown, an analysis in the DILO Lab is possible in advance.
  • The cylinder(s)/vessel(s) must be marked with the UN 3163 label for used SF6 gas
  • Only green vessels may be sent to DILO (yellow = toxic and corrosive)
  • As an additional service, we offer to change the labelling of the vessels from “yellow” to “green”.