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General Product Information

Improving the overall performance and competitiveness

One of the innovative solutions offered by Siemens to help you improve the overall performance and competitiveness of your gas turbine and combined cycle power plant is the Operational Flexibility Upgrade.

The Operational Flexibility Upgrade is an integration of proven products optimizing the individual power plant performance and increasing the operational flexibility within a long term service agreement. The Operational Flexibility Upgrade combines proven technology including improved blade and vane design and enhanced combustion technology. This modernization package is the entry card into a flexible operating regime extending the Original Equipment Manufacture coverage beyond 100,000 equivalent operating hours (EOH) and can be implemented at any outage during the long term service agreement program. 


The Operational Flexibility Upgrade includes a turbine performance upgrade modifying key turbine components and hot gas parts which may allow for a significant firing temperature increase. These results are achieved by new coatings for turbine blades and vanes and cooling air reduction in the hot gas path. Finally the CMF++ compressor is also part of the last OFU upgrade version. This modernization has been designed to help yield potential power increase, heat rate improvement and additional exhaust energy. In addition to the achieved performance increase, the Operational Flexibility Upgrade can allow for a maintenance interval extension resulting in an increased availability for the entire plant.


Your benefits


The Operational Flexibility Upgrade can be a cost-effective means to help you improve the overall performance of your gas turbine and combined cycle power plant integrating various technical solutions.

The Operational Flexibility Upgrade offers you a clearly technical and monetary quantifiable benefit.


Benefits may include: *

  • More operational flexibility for intermediate and cyclic operation
  • Up to 13 MW gas turbine power output increase in simple cycle operation
  • Up to 21 MW combined cycle power output improvement (1x1)
  • Up to 0.4 % points combined cycle efficiency improvement
  • NOX emission reduction down to 15 ppm possible


The hardware technology of the Operational Flexibility Upgrade is state-of-the-art for new SGT5-4000F (V94.3A) Siemens Gas Turbines manufactured since 2008.


* Subject to specific technical plant evaluation

Scope of Supply


The scope of this upgrade includes an optimized hot gas path, turbine and compressor components including instrumentation and control modifications:


Optimized hot gas path and turbine components:     

  • Latest design turbine blades stages 1 and 2
  • Latest design turbine vanes stages 1, 2, 3 and 4
  • Turbine ring segments and turbine vane carrier with modified cooling holes and turbine leakage air reduction
  • Improved metallic heat shield design
  • Cooling air reduced combustion chamber with improved cooling air pattern, new impingement cooled tile holders and optimized ceramic heat shields
  • Premix-Pilot burner with reduced swirl


Optimized compressor components:     

  • New inlet guide vane and the first two stages of compressor blades and vanes
  • New hydraulic inlet guide vane actuator and position sensor
  • New combined axial and radial compressor bearing with hydraulic axial shifting device and required hydraulic pump skid
  • Auxiliary systems for modified inlet guide vane adjusting device, hydraulic clearance optimization, two stage burner operation, and the fuel gas preheating equipment


Depending on the actual gas turbine configuration, the above mentioned hardware scope can be reduced. The Operational Flexibility Upgrade will be typically implemented at the 100,000 EOH outage.


Siemens Power Service offers a full range of field service capabilities to help you manage your maintenance and outage schedules. The Operational Flexibility Upgrade is retrofitable.


With the above mentioned scope of supply the Operational Flexibility Upgrade is applicable for the SGT5-4000F (V94.3A) frame and may be combined with other modernizations, e.g. Advanced Stability Margin Controller, Wet Compression, Evaporation Cooling, FODS and ACCSpro.

Click here to get the product information as a PDF:
Operational Flexibility Upgrade for SGT5-4000F Gas Turbines

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