The operating principle of oil bath rotary pumps is similar to that of lubricated rotary pumps, with the difference that here the stator is immersed in lubrication oil. This way, the oil performs both classic function of lubrication and sealant for air leaks.
Included there is a ballast device, which can be activated at the operator’s choice, designed to prevent the condensation of water vapors.

The oil bath rotary pumps are able to reach considerably higher pressure values than any other type of vane pump. The lack of a filtering system at the outlet discourages their use at pressures close to atmospheric pressure. There are two major types of these pumps. The first is the single-stage model, consisting of a single rotor/stator assembly.
The second is the double stage, where two rotor/stator groups are connected in series, i.e. the discharge of the first group is connected to the suction of the second: this type achieves lower absolute pressures than single-stage pumps.

Oil bath rotary pumps


The main fields of application are:

  • refrigeration
  • conditioning
  • laboratory applications
  • lyophilization
  • spectrometry
  • ultracentrifugation
  • research institutes
  • universities
  • pre-vacuum units in ultra-high vacuum units