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SF6 Surveys and Top-up

National Grid Engineering & Consultancy Solutions can give your business an all-in-one contact to cover your sulphur hexafluoride (SF6) needs, providing SF6 leak detection surveys, gas leak repairs and top-ups for assets.

Our engineers, trained to the latest regulations and gas handling techniques, are equipped with precise specialist instruments allowing us to pinpoint and resolve any issue, and in turn, reduce financial and environmental cost for your business. We provide:

  • certified SF6 engineers in line with UK and EU regulations 

  • expert knowledge of the SF6 filled equipment 

  • quick deployment to cover England and Wales 

  • one point of contact 

  • latest leak detection systems, analysers and gas carts 

  • effective reporting

Our solutions

We offer a range of solutions to suit your needs:

Leak detection surveys

Our highly experienced SF6 engineers can carry out leak detection surveys on your site using specialist thermal imaging technology, either to locate a specific leak or to survey entire SF6 filled installations; such as Gas Insulated Switchgear substations. This allows us to make strong recommendations as to where closer monitoring and repairs may be required.

Gas leak repairs

We will work with you to develop gas leak repair solutions that will be tailored to your site specifications to reduce financial and environmental cost. We use bespoke reporting tailored to your requirements. These reports identify the location of your leaks and can form the basis of a rectification plan.


Our experts can attend your site with equipment to empty or top up your SF6 assets. We can complete this service both pre and post maintenance. Alternatively, we can top up leaking assets for them to continue performing until a repair can be carried out.

Gas handling

Our team will use specialist gas handling equipment to remove and temporarily store SF6, allowing us to perform the necessary maintenance to restore your asset.

Customer stories: EDF Sizewell B

Sizewell B

National Grid Engineering and Consultancy Solutions complete SF6 gas works on several gas zones for EDF’s Sizewell B nuclear power station.

Read the full story

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