If your MS system includes oil-sealed rotary vane forepumps, you must routinely purge (ballast) volatile solvents and water vapor from the oil.
The best time to ballast the oil is at the end of the workday after you flush the inlet components. Daily purging of the oil removes water and other dissolved chemicals, which can cause corrosion and decrease forepump performance over its lifetime.
Refer to the forepump’s documentation for instructions and recommendations about ballasting. Make sure to close the ballast valve before continuing normal operation.
CAUTION
Make sure the pump is properly vented during balast; otherwise harmful chemicals can release into the lab.