Belzona’s advanced leak repair technology effectively seals leaks of greenhouse gas SF₆ in high-voltage electrical equipment

Rapidly applied solution allows repairs without outages, keeping grid infrastructure operational

Belzona SF6-FIX has been successfully deployed across multiple National Grid substations in the UK

National Grid is aiming to halve SF₆ emissions from its transmission network by 2030

SF₆ leak successfully sealed with Belzona SF6-FIX

National Grid is using a new solution from Belzona to rapidly and effectively seal SF₆ leaks, reducing emissions while keeping key grid infrastructure in service.

Belzona, a leading repair composites and coatings manufacturer, has developed a new solution now utilised by National Grid to seal leaks of Sulphur hexafluoride (SF_6).SF₆is an insulating gas commonly used in high voltage electricity equipment to prevent short circuits and ensure network reliability. While designed to be sealed, aging equipment can develop leaks, often requiring an outage for repairs.

Belzona SF6-FIX is a durable system of expertly applied specialist materials, that seals equipment leaks by encapsulating the affected area.

In late 2021, Belzona was invited to discuss its SF₆ leak mitigation solution with National Grid, leading to a trial application in 2022, followed by further testing and development in collaboration with the company.

Building on the success of these early repairs, Belzona has since completed multiple SF₆leak-sealing projects at substations across the UK, including Seabank, Stocksbridge, and Tilbury. With all repairs reported as performing well, Belzona SF6-FIX is now set to be deployed at additional locations, with 16 sites surveyed in 2024 and further applications planned for 2025.

As National Grid continues its efforts to reduce emissions and enhance network reliability, Belzona SF6-FIX is proving to be an effective solution for mitigating SF6 leaks across critical infrastructure.

In February 2025, National Grid engineers visited Belzona UK’s training facility in Hawarden to undergo comprehensive training on the application of Belzona SF6-FIX.

All Belzona UK technicians and engineers have been trained to National Grid Persons Standard, with some Belzona technicians also completing the National Grid Competent Persons training, ensuring their ability to carry out repairs on-site with greater ease.

Phil Robinson, Application and Training Director at Belzona said:

“It has been fantastic to work with National Grid to reduce SF₆ leaks using Belzona SF6-FIX. This collaboration demonstrates how innovative repair technologies can support the sustainable and efficient operation of power grids. By sealing SF₆ leaks quickly and reliably, we’re helping to minimise environmental impact while ensuring the resilience of the UK’s electrical infrastructure."

Rob Mills, Commercial and Portfolio Manager – SF₆ Emission Abatement at National Grid Electricity Transmission, said:

“Our collaborative work with Belzona, using its SF₆ leak seal technology, is helping us reduce SF₆ emissions while keeping our critical infrastructure in service. This means we can keep electricity flowing, while reducing the environmental impacts – a double benefit for consumers.”

Belzona SF6-FIX Supports National Grid’s Emission Reduction Goals

As National Grid continues its drive towards reducing greenhouse gas emissions, solutions like Belzona SF6-FIX will remain crucial in tackling SF₆ leaks and supporting the reliable operation of critical energy infrastructure.

The solution will play a key role supporting National Grid’s ambition to reduce emissions of SF₆ from its transmission network by 50% by 2030 (based on 2018/19 emissions).

For more information, please visit Belzona's website.

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