DILO Certified Gas: Mixing, reclaiming & analysing of gases
The better alternative. For everyone involved.
Gases such as SF6 or other insulating and arc quenching gases are indispensable for the safe operation of medium and high-voltage applications thanks to their unique physical properties. Over time, however, the arc quenching and insulating gases can become contaminated, which can greatly reduce their arch quenching and insulating properties: In such cases, the gas used must be replaced with new gas. Yet every newly produced kilogram of gas means potential new emissions and an additional burden on the environment. DILO's solution is simple: Turning old into new.
Eco-efficient alternative to new gas
The idea behind DILO Certified Gas is remarkably simple: Instead of producing new SF6 gas or a new alternative arc quenching and insulating gas mixtures, the used gas is simply reclaimed or mixed. DILO offers users and operators of gas-insulated equipment the option to either mixing or completely reclaiming the contaminated gas. This is not only more sustainable than purchasing new gas - it has been proven to deliver equal or even superior quality.
DILO Services for alternative arc quenching and insulating gases
DILO relies on precise gravimetric processes for the production of alternative arc quenching and insulating gas mixtures. This ensures that all components are precisely dosed and homogeneously mixed. The result is certified gas mixtures based on C4-FN, which guarantee maximum mixing accuracy and lasting stability.
At DILO, you get everything from a single source: from mixing and separation to reclaiming, analysing and delivery in TÜV-certified pressure vessels - either in gaseous or partially liquefied form. Upon request, we also take care of collection, return, and refilling directly into your system.
Reclaiming alternative arc quenching and insulating gases
DILO services for alternative arc quenching and insulating gases at a glance
- Mixing of alternative arc quenching and insulating gases (C4-FN and other gas mixtures)
- Separation/reclaiming and return
- Analytical services in the DILO laboratory
- Vessel services: Acquisition of purchase/rental cylinders, TÜV - repeat inspection, scrapping
Our checklists for alternative arc quenching and insulating gas enquiries
FAQ – Alternative arc quenching and insulating gases
What you need to know
If you have any further questions, please do not hesitate to contact our customer service team.
Does DILO also offer alternative gases such as C4-FN mixtures?
Yes. In addition to reprocessed SF₆, DILO Certified Gas also provides services for C4-FN-based and other alternative extinguishing and insulating gas mixtures: gravimetric mixing, separation and reprocessing, take-back, and analytical services in the DILO laboratory. During gravimetric mixing, the individual components are precisely metered and homogeneously blended – this ensures a reproducible composition and reliable documentation for every single batch.
We supply the certified gas mixtures in gaseous or partially liquefied form in pressure vessels, in accordance with the relevant specifications. Here too, we manage the entire cycle – from supply, through analysis and take-back, to reprocessing or professional disposal. We would be happy to discuss which gas or gas mixture is right for your application in a direct conversation.
Recovery, recycling, reprocessing, destruction – what do the terms in the F-Gas Regulation actually mean?
These four terms are often used interchangeably in everyday language. Legally, however, they describe clearly distinct processes, which are defined in Article 3 of Regulation (EU) 2024/573. Correct classification is crucial for documenting operators’ obligations:
| Term | Definition according to Regulation (EU) 2024/573 | Meaning in practice |
|---|---|---|
| Recovery (Art. 3(11)) |
The extraction and storage of gas from containers, products and equipment during maintenance, servicing or prior to disposal. | The extraction of gas from the switchgear – the first step, not yet a quality improvement. |
| Recycling (Art. 3(12)) |
Reuse of a recovered gas following a fundamental purification process, including filtration and drying. | Simple on-site purification, typically within the same operator’s closed-loop system. |
| Reconditioning (Art. 3(13)) |
Treatment of a recovered gas, whereby it attains properties equivalent to those of a virgin substance – in authorised processing facilities capable of assessing and certifying the required quality. | The process used by DILO Certified Gas: gas separation and regeneration to new-gas quality, with a certificate of analysis. |
| Destruction (Art. 3 No. 14) |
The permanent and, as far as possible, complete conversion or decomposition of the gas into stable substances that are not fluorinated greenhouse gases. | The route for gases that can no longer be recovered economically or technically. |
Important for practical application: Under Article 8(6) of the Regulation, recovered gas may not simply be used to fill or refill equipment – it must first have been recycled or reclaimed. Furthermore, under Article 12(7), containers holding reclaimed gas must be labelled accordingly, including the batch number and the name and address of the reclamation facility.
DILO services for SF6 gas
For reclaiming used SF6 gas, DILO relies on a cryogenic separation process. By precisely applying pressure and low temperatures, by‑products are removed in several stages until pure SF6 gas with a purity of ≥ 99.9% is obtained, which can then be reused.
At DILO, you receive the complete service from a single source: from collection to reclaiming and analysis to the return delivery of the reclaimed gas Upon request, we can also take care of used gas cylinders, pressure vessels and gas that can no longer be used - including disposal, repeated inspection by TÜV and reuse.
Reclaiming of SF6 gas
DILO Certified SF6 gas compared with IEC and ASTM standards
| 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 µl/l |
| Frost point (1 atm) | ≤ -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 | – | – |
DILO services for SF6 gas at a glance
- Supply of already reclaimed SF6 gas with a purity of ≥ 99.9%
- Reclaiming and return/disposal of contaminated SF6 gas
- Analytical services in the DILO laboratory
- Vessel services: purchase of new/rental cylinders, TÜV periodic inspection, scrapping
- Collection and return transport
Our checklists for SF6 gas enquiries
FAQ – SF6 gas
What you need to know
If you have any further questions, please do not hesitate to contact our customer service team.
Can DILO collect my used SF₆ gas, recondition it and return it to me?
Yes. DILO offers the entire process chain from a single source: from the collection and return of used or contaminated SF₆ gas, through analysis and reconditioning, to the return of the reconditioned gas with a quality certificate.
On request, we also provide additional services relating to used gas cylinders and pressure vessels – for example, periodic inspections, repair and reuse, scrapping, and the professional disposal of gas that can no longer be used.
To provide an initial quote, we simply need three pieces of information: the approximate volume of gas, the known gas quality – provided an analysis is available – and your preferred timeframe. We’ll sort out everything else together.
How long does it take to supply or process DILO Certified Gas?
We distinguish between the delivery and supply of gas that has already been reprocessed and the reprocessing of the customer’s own gas quantities.
Delivery and supply: We keep reprocessed SF₆ in stock at all times. DILO Certified Gas is therefore generally available immediately in our standard containers and can be supplied at short notice – including an analysis certificate and full F-gas documentation. For customer-specific requirements, such as different container sizes, special labelling or additional certification, we simply require a short processing time.
Reconditioning: The turnaround time depends largely on the quantity delivered, the initial quality of the gas and our current workload. Experience shows that the turnaround time for the entire process – from initial analysis through separation and regeneration to quality approval and return delivery – is typically a matter of a few weeks. We will agree a firm date with you individually once we have received your enquiry.
How does DILO Certified Gas assist with disposal, documentation and F-gas compliance?
DILO Service GmbH is certified as a specialist disposal company in accordance with Section 56 of the German Closed-Loop Economy Act. Take-back, analysis, reprocessing, reuse and disposal are therefore carried out within a framework that is regularly monitored and audited.
For operators, seamless traceability is of paramount importance. Regulation (EU) 2024/573 stipulates in Article 7 that operators must, amongst other things, record whether the gas supplied has been recycled or reclaimed, as well as the name and address of the recycling or reclamation facility within the Union. We provide you with precisely this information with every delivery – together with the analysis certificate, proof of destination and the prescribed container labelling.
What is DILO Certified Gas and what services does this division cover?
DILO Certified Gas (DCG) brings together all services relating to the life cycle of SF₆ and alternative insulating and extinguishing gases. This provides operators of electrical equipment with a single point of contact for the entire gas cycle. Our range of services includes:
- Take-back and recovery of used gases from electrical equipment, containers and systems
- Reconditioning of used SF₆ gases through gas separation and regeneration to new-gas quality
- Production and reprocessing of C4-FN gas mixtures, as well as the supply of other alternative gases
- Laboratory analysis to determine gas quality, moisture content, decomposition products and foreign gas content
- Professional disposal of gases that can no longer be reused
- Cylinder and logistics services, including the handling of dangerous goods in accordance with ADR
- Inspection, reuse or scrapping of used gas cylinders and pressure vessels
All steps are documented and can be traced from the receipt of the gas through to its return.
What is the quality of DILO’s reconditioned SF₆?
Reconditioned SF₆ from DILO achieves the quality of new gas. The term ‘reconditioning’ is clearly defined in the F-Gas Regulation: the gas must achieve properties equivalent to those of an unused substance. Our process is designed precisely for this purpose.
We use gas separation and regeneration, which enable even heavily contaminated batches or those mixed with foreign gases to be brought back into specification. Each batch is analysed before release; we document the results in an analysis certificate, which you can use immediately for your plant documentation.
The relevant international standards serve as a reference: IEC 60376 for the specification of SF₆ for use in electrical equipment and IEC 60480 for the reuse of SF₆ after extraction from equipment.
Analytical services in the DILO laboratory
The DILO laboratory offers a wide range of gas chromatographic and FT-IR spectroscopic analyses in the field of sulphur hexafluoride (SF6) its by-products and decomposition products as well as alternative C4-FN based arc quenching and insulating gas mixtures. Additional analytical questions in the field of gas analysis can also be addressed upon request Please do not hesitate to contact us.
FT-IR spectroscopic rapid analysis
With FT-IR spectroscopy, DILO analyses gas mixtures quickly and precisely - without complex sample preparation. The method utilises the characteristic light absorption of the molecules and creates a spectrum from which the composition and concentrations are determined. This allows both SF6 decomposition products and alternative arc quenching and insulating gas mixtures (e.g. based on C4-FN) can be reliably detected. Measurements achieve accuracies of down to ≤ 1 ppm and are analysed by DILO experts.
- Accuracy down to ≤ 1 ppm: even the smallest concentrations are reliably detected
- Easy sample delivery: only one gas cylinder with a minimum pressure of (0.3 bar relative) is required
GC/MS detailed analysis
With GC/MS analysis, DILO covers a very broad analytical spectrum:: gas mixtures are first separated chromatographically and then analysed by mass spectrometry. This allows common gases such as C4‑FN, SF6 or oxygen to be reliably detected in the ppm range, as well as even the smallest by‑products and decomposition products down to the ppb range. Every sample is examined by DILO specialists and documented with a certified measurement report.
- Highest precision: detection of decomposition products down to ≤ 100 ppb
- No sample preparation: simply submit the gas cylinder with a minimum relative pressure of 0.3 bar
Analysis of submitted samples
Would you like to have your gas samples analysed by DILO?
No problem. To ensure that your sample arrives safely and without contamination at our laboratory, DILO supports you in organising sampling and transport. Upon request, you will receive a fully equipped sampling kit containing all components for professional sampling, including sample vessels, hoses and connections. DILO also takes care of the logistics for sample transport to ensure a safe and efficient process.
- Safe sampling: fully equipped DILO kits for correct sampling
- Smooth process: complete organisation of transport and laboratory delivery
Your benefts at a glance
- Lower costs: no purchase costs for new SF6 gas
- Tax savings: no CO2 taxes for importing new SF6 gas, no regional taxes on the use of new SF6 gas
- Effective environmental protection: no resource consumption for the production of new SF6 gas, no environmentally harmful disposal of used SF6 gas
- Certified quality and waste management: all processes comply with IEC 60376, ASTM D2472-15 and GB/T 12022/2014 and are fully documented
- Maximum transparency: complete traceability from sampling to refilling - ensuring full safety and traceability
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Interested in DILO Certified Gas Services?
Whether mixing, reclaiming or analysing: we will be happy to advise you and find the best solution for your project. Please do not hesitate to contact us.
