Rotary evaporators are typically used to remove solvents following chemical reactions. Combined with gentle heat from the evaporator bath, controlled vacuum is used to bring solvents to boiling or near-boiling. Efficient solvent distillation requires vacuum balanced to achieve sufficient pressure reduction and molecular flow without losing sample or overrunning the condensing capabilities of your rotovap. To select the right vacuum pump for rotary evaporation, Welch Vacuum suggests to follow these 5 steps:

  1. Select a chemical resistant dry diaphragm vacuum pump for routine evaporations.
  2. Buy a vacuum pump capable of quickly evaporating your least volatile solvent. Fast stripping of DMF requires a 2 torr (2.67 mbar) diaphragm pump.
  3. The ability to adjust vacuum level and react quickly to bumping / foaming conditions are keys to preserving your sample and using your time efficiently.
  4. Automated diaphragm vacuum systems can help you save both sample and time.

Welch Vacuum offers a wide range of vacuum pumps and systems suitable for different flask sizes, allowing you to achieve ultimate vacuum levels of 75 to 1 mbar (56.3 to 0.75 torr), and flow rates of up to 138 l/min (4.87 cfm) in your rotary evaporators. Our portfolio also includes a variety of manual and electronic vacuum regulation options, including digital controllers to ensure reliable results.