Open drive screw compressors


The open type screw compressors OSKA, OSNA, OSK and OSN are designed for universal use in large commercial or industrial applications and marine refrigeration systems as well as explosion protection zones.

BITZER screw compressors offer decisive advantages:

  • high cooling capacity and performance coefficient with and without economiser operation
  • integrated, efficient capacity control: 100 % – 75 % – 50 %
  • from model OS.85, three-step or infinite slider control
  • high-quality and reliable shaft seal
  • reliable continuous operation through patented lubrication system and generously dimensioned bearings
  • suitable for all current refrigerants
  • standard motors can be flanged directly to the optional coupling housing without costly alignment work. Clutches are also available as accessories.

The capacity range of single compressors covers up to ten displacement stages parallel operation with up to six compressors is possible. Parallel circuits offer further advantages of the system:

  • high system reliability and redundancy without over-dimensioning
  • virtually infinite capacity control
  • high part load efficiencies by powering compressors up and down
  • compact compressor system with simple maintenance and service.


Additional Information

Technical details

  • Energy efficient
  • Universal
  • Robust design
  • Quiet and low vibration
  • Multifunctional through parallel compounding
  • Automatic start unloading
  • High-quality shaft seal
  • Approves, long-life bearing with pressure unloading