NASH liquid ring vacuum pump and Compressor[Oct. 4, 2010 2:44:54]
Nash Liquid Vacuum Pump and Compressor that use a rotating seal liquid in lieu of piston, vanes or rotating lobes are the sensible choice as they provide you with other alternatives: No metal to metal contact, no internal lubrication required, only one moving part- no vanes, no valves no timing gear or chains