Sealing Sulphur Hexafluoride leaks from small bore pipework

Britain’s National Grid Electricity Transmission (NGET) and UK-based technology company, Rawwater, are collaborating to trial a novel means of sealing harmful environmental leaks of Sulphur Hexafluoride (SF6) by reducing emissions from small bore pipework. A powerful greenhouse gas, SF6 is a safety feature of gas insulated switchgear (GIS) equipment, a key component of electricity transmission systems.

The process uses Rawwater’s M3 (Molten Metal Manipulation) low-melting-point bismuth alloy leak-and defect-sealing technology and involves the use of either a ‘leak extinguisher’ alloy spray (M3Spray) or an easily-deployed collar (M3CollarCast) where molten alloy is cast into a reusable mold. Both application techniques require no curing time, allowing for in-service application against flowing leaks.

“We are delighted to be working with National Grid,” said Rawwater’s Kat Lennox. “It will be many years before SF6 is eradicated from electricity supply networks globally. Until that day, a rapidly-deployable solution is required to seal or mitigate SF6 leaks. We believe M3 Molten Metal Manipulation is part of the answer.”