What Is SF6 Gas?

Ah yes, sulfur hexafluoride gas. That stuff you may have seen on the Jimmy Fallon show that has the opposite effect of helium, making Jimmy and his guests sound like Darth Vader. Besides being a fun party trick, sulfur hexafluoride gas (SF6) has a very practical use in our modern electrical infrastructure.

Characteristics of SF6 Gas

SF6 Gas is a colorless, odorless, non-flammable, and harmless to humans and animals in low quantities. It is an incredible electrical insulator, which is why it is used as an arc quenching medium for higher voltage switch-gear. So what are the negatives? Unfortunately, SF6 has been deemed as the most potent greenhouse gas that has ever been evaluated. It has a global warming potential of 23,900 times that of CO2 when calculated over a 100 year period. To put that in perspective, you could get 23 of your buddies and fly from New York to Paris and back, and it would have the same potential effect on global warming as letting just a few pounds of SF6 out of a bottle. Yikes. Luckily, SF6 gas is very heavily regulated and monitored in most developed countries (thanks Kyoto Protocol), and the amount currently in the atmosphere is a fraction of a percentage of the overall greenhouse gas problem. And we aim to keep it that way!

Why is SF6 Gas Used in Electrical Infrastructure?

When medium to high voltage electrical systems are turned on and off, there is a massive amount of energy that is transferred from one conductor to another, which causes a large electrical arc. This is very similar to you plugging in your lamp and there being a small spark of electricity between the plug and the metal prongs on the cord. To give some context, most residential plugs are putting out about 15-20 amps. Sulfur hexafluoride can be used on switch-gear that is up to 6,300A (6.3kA), or about 420 times that of your home plug. Such a powerful electrical arc can severely damage surrounding components. Enter SF6 gas.

How is SF6 Gas Used in Electrical Infrastructure?

The actual gas is used as a dielectric medium between the two conductors in a switch. What this means is that as an arc is formed, it is quickly quenched by the SF6 Gas. The actual SF6 gas itself is ripped apart by the immense amount of energy passing through it, but much like wolverine (or Deadpool, Spiderman etc.), the gas heals itself and recombines at the atomic level. Unfortunately, other byproducts can also be formed like water and sulfur dioxide, which causes problems for the longevity of electrical components. Hence the need for good testing equipment.

The Future of SF6

Although other arc quenching methods have been developed, sulfur hexafluoride remains the most popular and cost effective for medium to high voltage. This gas will be around for a long time, with legacy systems already in place, and the global installed base of SF6 expected to grow by 75% by 2030. At GasQuip, we aim to help eliminate all emissions of SF6 gas by providing the technology and services needed to responsibly handle all SF6 applications.