SF6 Apparatus Contamination and Evacuation Software
Use this software to determine the required level of evacuation to safely work SF6 insulated circuit breakers.
Enter the SO2 and HF contamination levels that you find in your breaker. Choose your method of decontamination (purification run or gas evacuation and vacuum followed by fresh air flush).
If you choose Purify then you will enter your gas contamination level after the first purification run, (this sets your purification efficiency).
If you choose air flush then you will save your gas then vent your tank to atmosphere for a single evacuation. A second pump down then vent to atmosphere, a third pump down and vent to atmosphere are calculator choices. The variable input for this option is the vacuum capability of your pump system.
You can set your choice of values for SO2 and HF safety limits. The calculator then calculates the level of contaminants after a second or third pass.
This screen shows you that if you purify your SF6 through a 90% efficient system then you may still have hazardous levels of SO2 and HF after a single pass through your purification system. The initial contamination level was 2000ppm SO2 and 3000ppm HF. The 90% efficiency level of your purification system will not clean enough contaminants to safely work in the SF6 compartment unless you can remove all gas.