Air insulated substation means air acts as the dielectric medium but in case of gas insulated substation SF6 is the dielectric medium. Gas insulated substations are having more advantages than air insulated substations.
gas insulated substations are installed especially where floor area available is limited and maintenance cost is more
Air insulated means the substation is in the open air, and the dielectric strength of the air is used to isolate conductors from each other and from ground. Gas insulated means a specific gas is used for insulation; this gas is usually an inert gas such as nitrogen. Gas insulated substations, by definition, are required to be inside a contained structure, or large piping must be placed around all conductors to hold the gas.
Gas insulated substations do have some advantages. They are preferred in cities and large towns, and are considered to be safe, reliable, and maintenance free.
sulphur hexa-fluouride
Gas insulated substations are in use in places where a normal, above ground substation would constitute an eye sore for the community. A gas (SF6) insulated substation may have underground feed lines and be nearly invisible to the average person -- except for the location where the transmission feed wires go underground from the transmission towers. distribution circuits supplied by gas insulated substations normally have an alternate feed from another substation, to allow maintenance work on the gas insulated site.
it requires lesser space compare to normal. design of switch gear is more compact , has the potentials to increase system reliability and has less maintenance and longer service life.
the DX gas station.
A gas station :)
The first gas station ever to start selling gas for 50 cents a gallon was called gargoyle gas station located in folks philledelphia. (GG) and it was very popular in the 1880's.The second gas station was called Rivers Gas station in kentucky.
Gas or train many stuff train station gas station
Tramway Gas Station was created in 1965.