The Welch-Ilmvac 2200B-01 is a powerful, dry, chemical duty vacuum pump with a built in controller and automatic evaporation machine. The sophisticated controller of the Ilmvac Variable Speed Evaporator Vacuum System automatically sense vapor and remains at the correct pressure until evaporation is complete, eliminating bumping of product. The flow of 16 lit/min, along with the deep ultimate vacuum of 1.5 Torr, makes this pump the perfect solution for a bench top rotary evaporator. The Evaporator Vacuum System can be used for any harsh chemical service, but the lower flow makes it an excellent pump for small rotovaps/distillations/evaporations. The Evaporator Vacuum System is designed for quick and easy, infrequent maintenance.