LEC III™ Ultra Low Emission Combustion System

Sub-5 ppm NOx combustion retrofit for GE and Siemens B/E-class gas turbines. Field-proven since 1999. 100+ installations worldwide. HyFlex version supports hydrogen co-firing.

PSM’s LEC III system is a trusted solution for reducing NOx and CO emissions in gas turbines while maintaining high performance and operational flexibility. Developed and manufactured by PSM since 1999, LEC III is the company’s founding technology, with over 100+ systems sold globally across GE 6B, 7B/EA, 9E, and Siemens/Westinghouse platforms. The system delivers sub-5 ppm NOx on natural gas and low CO emissions across a wide-load range, helping operators meet strict environmental regulations without sacrificing efficiency. The HyFlex version of LEC III supports hydrogen/natural gas fuel blends, with three 9E units in the Netherlands operating on up to 25%hydrogen since 2018.

Field Proven 3-5 PPM NOx Performance

A Track Record You Can Count On

Backed by decades of real-world success, the LEC III system achieves ultra-low NOₓ levels (3–5 ppm) using advanced forward-flowing venturi design and effusion cooling technology. It operates efficiently from baseload down to 50%–60%relative load (or 80% with IBH), with low CO output in all conditions. This enables plants to meet permit requirements while improving air quality and sustainability metrics.

Seamless Integration

Drop-In Replacement or Modular Upgrade

The LEC III can be installed as a complete system or as individual part replacements for OEM DLN1 systems on B/E-Class turbines (GE Frames 6B, 7B/EA, 9E, and Siemens/Westinghouse 501B6/D5). It supports both drop-in conversions and full replacements—no major control system changes needed. This flexibility lets operators upgrade at their own pace while preserving their investment in legacy assets.

Better Combustion Starts With Better Mixing

How LEC III Lowers Emissions at the Source

The heart of LEC III performance lies in its ability to thoroughly premix fuel and air before combustion. This design minimizes NOₓ and CO formation. Key features include:

  • Effusion-cooled premixers
  • Optimized flow sleeve and venturi design
  • Fully premixed secondary fuel nozzle

These elements work together to reduce combustion dynamics, improve flame stability, and ensure cleaner operation.

Enhanced Durability with LEC NextGen

Upgraded Design for Extended Life and Flexibility

For users who require even broader operating flexibility, PSM offers LEC NextGen—a dual-fuel capable evolution of the LEC III™. Designed for compatibility with 7121EA, 9171E, and older turbine models, it offers:

  • Up to 32,000 factored fired hours between inspection
  • Dual-fuel capability
  • Enhanced wear protection with thicker liners and flowing cap
  • Compatibility with IBH and PAG steam for extended turndown

LEC NextGen delivers durability and low emissions while accommodating a wider range of fuel types and system configurations.

Why Choose LEC III™ or LEC NextGen?

Smart Combustion. Real Results.

PSM’s combustion systems are engineered to reduce emissions while supporting long-term operational goals:

  • Reduce NOₓ to <5 ppm
  • Lower CO output
  • Extend maintenance intervals
  • Improve turn-down and part life
  • Support global sustainability goals
  • 100+ installations globally and growing

Operators around the world trust LEC systems to meet regulatory demands, optimize performance, and enable decarbonization, all without costly system overhauls.

Want to learn more about Flamesheet options?

LEC-Next Gen Brochure
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350+

Gas turbine upgrades installed globally

230,000

CO2 reduction per decarbonized turbine equals removing 230,000 cars from the road

100%

Hydrogen combustion: current target for FlameSheet platform

1999

Year founded, 25+ years of gas turbine engineering

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