Siemens STC-SR Compressor Series

Perfect Compressor Solution for Air Separation

Numerous applications, e. g. methanol production, Gas-to-Liquids (GTL) and Coal-to-liquids (CTL), steel plants or Integrated Gasification Combined Cycle (IGCC), require large amounts of air or oxygen. Having built the world’s largest air compressor so far in operation, Siemens has outstanding expertise in compressors with large volume flows.

The Siemens STC-SR compressor series is the answer for today’s air separation requirements – demanding ever larger compressor units with increased efficiencies. These axial-radial turbocompressors are designed according to API 617 and optimized to handle large volume air flows while maintaining excellent efficiency, thus perfectly meeting customer needs.


  • The perfect match for air flows up to 1,300,000 m³/h
  • Axial-radial design allowing for intercooling and higher pressure ratios
  • Excellent efficiency


Design Concept

Modular Design
The design principle common to the Siemens STC-SR turbocompressors is a modular concept. It is based on finely graded machine elements and flow components that have proven their reliability for more than 50 years. This compressor series comprises an axial process stage together with one, two or three radial stages. It is configured in one casing with intercooling possible after each process stage.

Highest Flow Rates
Designed for large volume air flows within small casings, Siemens axial-radial compressors guarantee excellent efficiency. Fulfilling the highest technical standards, the compressor design is in accordance with API 617.


  • Up to ten axial and three radial stages
  • Up to three process stages
  • Intercooling possible after each process stage
  • Outstanding blading technology
  • Tilting pad bearing for journal and axial thrust bearing

Control Systems

  • Broad range of appropriate control systems:
    • Performance control
    • Independent anti-surge protection
    • Anti-choke control
  • Control by either speed variation or adjustable guide vanes, or a combination of both

Technical Data

  • Flow rates from 50,000 to 1,300,000 m³/h (30,000 to 765,700 cfm)
  • Pressure ratio between 5.8 and 16.0
  • Various control systems to optimize operation
  • Driver: electric motor or steam turbine, depending on process and energy resources


Combining reliable technology with innovative development, Siemens STC-SR axial-radial turbocompressors assure the following benefits to optimize your business:

  • Compression of largest volume flows
  • Highest degree of efficiency
  • Modular and robust machine design
  • High quality due to proven components and API standards
  • Low operating and maintenance costs