Oil-sealed Liquid Ring Systems – Pros & Cons

EMSE water-less (oil sealed) liquid ring system utilizes design features of both liquid ring and rotary vane vacuum pumps. The heart of the system is a liquid ring vacuum pump which can take a slug of water without damage. They are free of vibration and run very quiet. The pump system requires no water. It is completely air cooled. There is no need to be concerned with the sometimes substandard water quality causing corrosion of the vacuum pump internals. There are no water and sewerage costs as well as no requirements for chilled water. Best of all, because it is a liquid ring pump, it is virtually maintenance free. Oil and filter changes are required only after 2 years. In fact, these pumps are provided with a five year warranty.



  • Simple, time-proven design
  • Capable of taking slugs of water
  • Air cooled
  • No rust and scale problems
  • Low maintenance
  • No water and sewage costs
  • Low operating costs
  • 5 year warranty


  • Unsuitable for a dedicated anesthesia evacuation system
  • Lower capacity per horsepower when compared with the lubricated rotary vane pumps

The EMSE Design Guide

The EMSE interactive Design Guide calculates total demand, recommends multiple system designs, calculates intake, exhaust, riser, branch and zone piping sizes--all optimized based on user input. Start designing your system now.

Go to Design Guide