Siemens STC-ECO Compressor Series

Electrical, Canned and Oil-free

The Siemens compressor series STC-ECO meets the challenges of upstream dirty-gas compression and other demanding applications which have traditionally suffered from poor seal reliabilty. Siemens STC-ECO is a family of hermetically sealed, canned motor/compressors suitable for application in the upstream, midstream and downstream parts of the oil and gas industry. The integration of a high speed motor and a multistage centrifugal compressor allows minimizing the number of interfaces to basically: the power feed to the motor and the suction and dicharge nozzle of the compressor. Visionary craftsmanship founded on Siemens’ intellectual power in rotating equipment and electrical engineering. Blending of several leading technologies into a simple concept with unique benefits. Born out of creativity and harnessed through rigorous component qualification and unit testing in close cooperation with major oil companies. STC-ECO is Siemens response to the need to reduce the environmental footprint and life cycle cost in oil and gas operations. Therewith the Siemens STC-ECO is our platform for further evolution of the concept towards subsea compression.


  • The minimized amount of components in the system increases the overall reliability of the unit or plant
  • The use of a can avoids gas from entering the electrical components like the stator and the magnetic bearings
  • No dry seals and seal support systems reduces the emissions
  • Robust design allowing high nozzle loads
  • Siemens has made the STC-ECO in a vertical arrangement, this has the advantage of reduced footprint and a single drain point


  • Petrochemical plants
  • Refineries
  • Fertilizers
  • Oil and Gas industry (on-/offshore)
  • Compression solutions for: Natural gas, liquefied natural gas (LNG), FPSOs, fluid catalytic cracking (FCC), wet gas, sour gas (gas gathering, gas / oil separation)

Design Concept

Siemens STC-ECO – A fully proven solution

Representing a quantum leap in compressor technology, the hermetically sealed motor-compressor STC-ECO has been co-developed by Shell and Siemens, two companies enjoying a long-standing mutually cooperative relationship. Key to the success of the project, the Shell research team has been part of the joint development group. The concept was later qualified, developed, improved and installed with other major international and national oil companies as well. To date, the Siemens STC-ECO is the only API-conforming sealless compression solution available for dirty-gas applications without need for clean-gas supply.

Siemens has several references with the STC-ECO operating with dirty process gas in modulating mode, with our first reference established in 2006. During this time, the units were subjected to a wide range of contaminants, including sand and water – but also high CO2 und H2S content. Several in-house and site tests support our confidence in providing its robustness and achieving the desired 5-years maintenance interval, which have been among the key performance criteria in the development of the Siemens STC-ECO. The Siemens STC-ECO is delivered as a compact, modular and mobile skid-mounted unit available with an integrated air cooler or water cooler.

Control Systems

  • Perfect protection and process control via flexible Siemens control systems:
  • Anti-surge protection
  • Performance controllers acting on mass flow, suction or discharge pressure
  • Fully or semi-automatic start-up and shutdown sequences exactly matched to your process demands
  • Certified safety systems available
  • Local and remote control
  • Load-sharing controller for parallel trains

Technical Data

  • Volume flows from 250 to 10,000 m3/h
  • Discharge pressure up to 220 bar
  • Speed up to 13,000 rpm
  • Electric motor drive (canned, variable speed)
  • Active magnetic bearing technology


Due to flexible design and sophisticated technology, Siemens STC-ECO compressors represent the following benefits to strengthen your industrial processes:

  • Canned and hermetically sealed design
  • Suited for comprehensive range of process gases (handles any gas)
  • Project-specific design
  • Excellent degree of efficiency
  • Low operating and maintenance costs
  • Compact and low weight
  • Zero emissions
  • Speed variation of 30 to 105 percent speed
  • Increased uptime and safety
  • Suitable for application in the upstream, midstream and downstream parts of the Oil and Gas industry