Siemens STC-GT Compressor Series

Proven Concept for Direct Power Recovery

Siemens integrally geared process-gas radial turbines enhance power supply in processes with off-gas or process gas as byproducts. A medium to high-temperature gas can be used to drive a compressor or an electric generator directly, with no need for additional heat exchange or steam generation equipment. The Siemens STC-GT product line is the ideal solution for gas expansion within a number of chemical processes, and is designed according to both API 617 and API 672.


  • The perfect match for expansion of off-gas and process gas
  • Increases plant efficiencies
  • Reliable design concept based on integrally geared compressors


  • Purified terephthalic acid (PTA)
  • Dimethyl terephthalate (DMT)
  • Nitric acid

Design Concept

Part of the Integrally Geared Family
Based on the Siemens integrally geared centrifugal compressor concept, the STC-GT series comprises a broad range of proven design components. To ensure the highest technical and process standards, Siemens STC-GT process gas radial turbines are designed in accordance with API 617 and API 672.

Flexible Train Integration
For economic part-load operation, the Siemens STC-GT can be fitted with an adjustable inlet guide vane unit. This unit is normally located in front of the first stage, offering very good turn-down and part-load efficiencies. Depending on the process conditions, the Siemens STC-GT series stages can either be integrated in a multi-service STC-GV machine, or designed as a separate unit.


  • Stainless steel to prevent corrosion
  • Up to three stages
  • Radial inlet to each stage
  • Interheating between each stage
  • Integrally geared multi-stage design, freestanding (Siemens STC-GT) or integral part of a compressor (STC-GVT)

Technical Data

  • Gas inlet temperature up to 550 °C (1,020 °F)
  • Maximum inlet pressure 20 bar (290 psi)
  • Discharge volumes up to 600,000 m³/h (340,000 cfm)
  • Power recovery up to 45,000 kW (60,000 hp)


  • Proven design concept
  • Highest technical standards according to design codes API 617 and API 672
  • Long life due to process-optimized materials
  • Enhanced process and plant efficiency