For 1 -10 liter Rotary Flask your process will operate well with either a Welch Self cleaning PTFE diaphragm vacuum pump or basic Welch PTFE diaphragm pump. The self cleaning pump has additional accessories, including a pressure gauge, anti-bumping switch, inlet and exhaust catch-pots and cleans itself after use. All vacuum pumps on this site are the best in their class in quality and performance for the specific applications and processes. Please contact us for assistance.