Background
Gas-insulated switchgear (GIS) used to be filled with pure SF₆. SF₆ has a very strong greenhouse effect, so standards later allowed a 70% N₂ mixture, that is 30% SF₆ plus 70% N₂, with the concentration deviation held within ±1%.
The difficulty
Equipment makers apply a tighter factory limit, usually 30% ± 0.5%. SF₆ has a high molecular mass and a low saturation vapor pressure, which places demands on both the flow measurement algorithm and the gas path design.
What we did
The measurement and control algorithms of the V series suit SF₆ well. Together with customers we optimized the gas path and operating method of mixing equipment, and we have built up considerable experience in using MFCs well in this kind of equipment.
What we can provide
Besides MFC products, we can advise on gas path layout, MFC configuration and mounting position, and commissioning methods. The final concentration depends on the complete mixing system and its verification; each project must be confirmed against pressure, flow and gas path conditions.
