These Edwards nXDS gas ballast purge adapters may be fitted in place of the original gas ballast control knob and used to supply an inert purge gas, such as nitrogen. They are commonly used with the nXDS-i "standard" and nXDS-ic "chemical resistant" series dry scroll vacuum pumps. It is important to replace the gas ballast control knob with this purge gas adapter when you are using the nXDS pump on chemical applications, please read below. The gas ballast is a control valve, that intentionally introduces a small room-air leak into the second stage of the vacuum pump, producing a positive flow throughput, and sweeping out vapors from volatile compounds, such as, water and others. When pumping volatile compounds, like water vapor, they are compressed inside the pump and condense into a liquid. When condensation happens the ultimate vacuum pressure of the pump is now limited to the vapor pressure of the volatile contaminating compound, for example, the room temperature vapor pressure of water is around 23.8 Torr. The gas ballast should be opened while the pump is warmed up to help evaporate and sweep out the volatile vapors. It is often good to leave the pump running overnight with the gas ballast open to rid it of volatile compounds. The gas ballast should not be used when pumping flammable compounds, as the gas ballast introduces air which contains oxygen. The gas ballast should also not be used when pumping toxic compounds, as the gas ballast introduces a leak into the room air, if the pump is turned off, a small amount of vapors from inside the pump could potentially leak out through the gas ballast port into the room air. These Edwards nXDS gas ballast purge adapters have part number A735-01-809.
Works With Edwards nXDs Series Dry Scroll Vacuum Pumps:
- Edwards nXDS6i
- Edwards nXDS10i
- Edwards nXDS15i
- Edwards nXDS20i
- Edwards nXDS6ic
- Edwards nXDS10ic
- Edwards nXDS15ic
- Edwards nXDS20ic
