Special SF6 solutions

Units for special applications

Sophisticated technology and years of experience are the basis for individual solutions. We supply a wide range of special equipment for an emission-free SF6 gas handling – precisely tailored to the needs of our customers. We consider each new request as an exciting challenge that we are happy to face.

Purification and preparation of SF6 gas mixtures

In practice, it often happens that the used SF6 gas is contaminated with air by inadequate evacuation or not proper gas handling. Used SF6 gas containing an unacceptably high percentage of nitrogen and air can be prepared by DILO Separating plants to the desired quality. It can then be reused in gas compartments and consequently, costs for storage, disposal, transportation and the expense for new gas can be minimised.

The purity degree of the prepared SF6 gas corresponds to the following standards:
IEC 60480 – guideline for used SF6 gas
IEC 60376 – guideline for new SF6 gas
GB/T 12022/2006 – Chinese standard for new SF6 gas

  • Purity degree of the reclaimed SF6 gas: ≥ 99 %
  • Gas mixtures with an SF6 concentration of 40 – 98 % can be separated
  • Automatic analysis of the gas mixture and optimisation of the separation process
  • Integrated gas return system
  • Version for the preparation of SF6 / leaks CF4 gas mixtures is available

Units for gas insulated transmission lines (GIL)

For this special application we supply different high performance devices. Thus efficient handling of large volume GIL lines is no problem.

Product range:

Production plant for gas insulated lines (GIL)
  • Compressed-air preparation plants for pressure tests on GIL
  • Powerful vacuum pump units with Roots blower for evacuation of air (final vacuum < 1 mbar)
  • Mixing and filling plants for homogenous gas mixture with an SF6 percentage of 10 to 80 %
  • High pressure recovery units (final vacuum < 1 mbar) for storage of gas mixtures up to 250 bar
  • Large mobile filter units for drying gas
  • Cylinder bundles for storage of gas mixtures



Refrigeration units for gas insulated transformers (GIT) and accelerator plants

The essential advantage of our refrigeration units is that the cooling is carried out by means of water outside the transformer. This is to prevent the transformer from being damaged if leaks occur. The cooling systems can be connected to the gas insulated transformer directly and are optimally suited for continuous operation.

Refrigeration unit for gas-insulated transformers


  • Circulating pump: 30.0 m³/min
  • 30 l dry filter with compressor
  • Cooling capacity: ~ 45 kW

SF6 units for accelerators

We also deliver custom-tailored solutions for the SF6-gas handling of electron accelerators. Compared to the “normal” gas handling in the energy sector, larger SF6 gas volumes – usually several tons have to be handled in the field of electron accelerators.

Therefore, highperformance system components as well as large supply lines (up to DN 100) are needed, so that the gas volume can quickly and effectively be filled from the storage tank into the accelerator and recovered again. The SF6 gas is filtered during operation by aid of large filter units and dried at the same time.

On customer request we connect several accelerator units over the hall piping on the central gas handling plant.

Gas handling plant for SF6 pressure turbulence channel

SF6 gas handling plant for an SF6 pressure turbulence channel with remote control for local operation. The plant serves for evacuation, gas recovery, and filling of a large volume wind tunnel.

SF6 gas handling plant