SF6 Leakage in a 225kV Substation
SF6 Leakage in a 225kV Substation
(OP)
Could anyone advise about the different methods of repair for the leakage of the SF6 Gas in a GIS 225kV susbtations.
Also i will appreciate if anyone can recommend specific web sites for this concern.
Also i will appreciate if anyone can recommend specific web sites for this concern.
Elecme






RE: SF6 Leakage in a 225kV Substation
In a previous life we used a SF6 leak detector from GasVue with great success. http://www.sunline.net/lis/gasvue.htm
Sorry I can't help with much more. Cheers
RE: SF6 Leakage in a 225kV Substation
I'd call any of the major circuit breaker manufacturers - they will be able to do the necessary maintenance.
I'm sure you know that a HV breaker that is low on SF6 may fail catastrophically trying to interrupt a fault.
RE: SF6 Leakage in a 225kV Substation
Since all GIS design varies for each manufacturer and voltage levels. The spare parts are can not be interchanged or found outside the GIS factory.
Using unqualified personel could be dangerous and enviromental questionable since the SF6 is classified as a green house gas.
In my oppinion, the potential savings do not justify the risk. Therefore, It is strongelly suggested to contact the equipment manufacturer (after sale/service department) specially if the installation are still are under guaranty.
If you are looking for ben educated in handling, storage and SF6 reclaiming technology I suggest to log in the following sites:
http://www.epa.gov/highgwp1/sf6/pdf/loppt.pdf
http://www.epa.gov/highgwp1/sf6/pdf/dililloppt.pdf
http://www.tde.alstom.com/p-c/ftp/docs/papers/PS909RJE.pdf
RE: SF6 Leakage in a 225kV Substation
RE: SF6 Leakage in a 225kV Substation
You have a valid questionan. How the Sf6 travell to the atsmosphere? This is a mistery for me. Perhaps the enclose publication could help us.
Science Magazine, 28 July 2000.
".....How do we know the atmospheric increase of this gas? The Max Planck Institute for Chemistry in Mainz has participated in expeditions in Antarctica to extract air samples from the thick firn layers (snow).
These layers can be up to 100 meter thick and contain old air, sometimes reaching to the beginning of the last century. This air has been extensively analyzed in our institute and in Norwich, England. The new gas was discovered at extremely low concentrations.
At the surface the concentration is the same as in the air at the moment, and amounts to about 0.1 ppt (parts per trillion; one ppt is one part in 1012). At 100 meter depth in the snow its concentration was close to the detection level of 0.01 ppt.
This shows the grown of the gas during the second half of the last century. Because the increase of the new gas is very much like that of SF6, we suspect a link between the two gases."
RE: SF6 Leakage in a 225kV Substation
Now that it has entered the regulatory world, the physical reality of the situation is no longer relevant.
RE: SF6 Leakage in a 225kV Substation
What do you recomend for the repair of this leakage?
Elecme
RE: SF6 Leakage in a 225kV Substation
1.- SF6 gas leakages are very nasty, as one hair beneath a joint or o-ring can cause leakage, you have to use very sensitive detectors as recommended.
2.- leakages as I experienced are normaly in flanges area, so problems in joints and rings due many times of ageaing of bad compounds, installation defects, moisture, etc.
So first take out the gas of that section (service car or SF6 pump), taking account safety regulations (EPA, OSHA, or own countrie`s).
Clean the flange surfaces and polish if necessary, and use silicone grease so as to seal from moisture to enter.
Some makers use special grease (Fomblim, BarrierTA) in the SF6 side and for the rings.
3.- Vacumm must be applied and maintened so as to evacuate any moisture, and finally remplish with gas (from service car or bottles).
4.- Check for leakage (detectors such as used for industrial Freon refrigeration systems, or soapy water).
This may vary, so will be better to ask your GIS maker for the complete procedure.
I hope will serve you