The ability to use any liquid allows the liquid-ring vacuum pump to be ideally suited for solvent (vapor) recovery. For example, if a process such as distillation or a vacuum dryer is generating toluene vapors, then it is possible to use liquid toluene as the sealant, provided the cooling water is cold enough to keep the vapor pressure of the sealant liquid low enough to pull the desired vacuum. Ionic liquids in liquid-ring vacuum pumps can lower the vacuum pressure from about 70 mbar to below 1 mbar. References Pumps Gas technologies