The LM2500+G4 is an advanced variant of the LM2500+ aeroderivative gas turbine, designed to provide increased output and thermal efficiency through a set of targeted design upgrades. It retains the core architecture of the LM2500+ but introduces changes to the flow path that increase overall engine performance.

The primary difference between the LM2500+G4 and the LM2500+ is the increased flow capacity in the high-pressure (HP) compressor, HP turbine, and low-pressure turbine. These modifications raise the overall pressure ratio from 23.6 to 24.2, resulting in higher thermal efficiency and greater mass flow. The design changes are relatively limited, focusing mainly on minor geometry adjustments to blades and vanes to accommodate the increased flow.

In the high-pressure turbine, the G4 version includes improved blade cooling and upgraded materials. These changes enable the turbine to handle higher temperatures, contributing to both improved performance and component durability. To maintain proper rotor thrust balance with the updated flow path, the effective area of the compressor discharge pressure seal was also adjusted.

In terms of operational performance, the LM2500+G4 offers measurable improvements over the LM2500+ across a variety of ambient conditions. For example, it delivers approximately 11% more power in cold conditions and 12% more in hot conditions (running data to -50 deg F and start data to –40 deg F). In combined-cycle mode, the G4 variant is expected to provide a power increase of 8.5% and a heat rate improvement of 0.75% compared to the LM2500+.

The LM2500+G4 supports two power turbine configurations:

• A six-stage, low-speed power turbine, typically used for power generation applications with a nominal speed of 3600 rpm.
• A two-stage High-Speed Power Turbine (HSPT), used for mechanical drive applications, designed for a nominal speed of 6100 rpm, with an operating range from 3050 to 6400 rpm.

Both configurations support operation over a cubic load curve, which allows the turbine to match power output with varying mechanical loads — a feature especially useful in pipeline compression and similar variable-load industrial applications.

The LM2500+G4 SAC 50Hz Combined Cycle 1x1 is a gas turbine system that combines a gas turbine with a steam turbine to improve overall power generation efficiency. This configuration captures waste heat from the gas turbine exhaust and uses it to produce steam, which then drives the steam turbine, generating additional electricity. This approach helps maximize power output while making better use of fuel energy.

Building on the LM2500+ design, the LM2500+G4 increases power capability by about 10% without reducing the lifespan of critical hot section components. This is achieved by increasing airflow, enhancing materials, and improving internal cooling. Despite these upgrades, the core compressor and turbine stages, as well as most airfoil and combustor designs, remain consistent with the LM2500 model.

The LM2500+G4 features a 17-stage high-pressure compressor that raises the engine’s pressure ratio and airflow, boosting the total power output of the gas turbine to over 31 MW. It uses a Single Annular Combustor (SAC) equipped with water injection to help control emissions while maintaining stable combustion. The SAC’s simple, proven design provides uniform flame temperature and reliable operation.

This balanced system is common in industrial and energy applications where efficiency and power output must be optimized, especially under varying ambient conditions. The combined cycle setup offers a reliable and efficient solution for electricity generation in demanding environments.

The 2” Globe-Style Gas Metering Valve is designed to provide precise regulation of fuel gas flow in industrial and aero-derivative gas turbines. Its globe valve design offers excellent throttling capabilities, allowing fine control over fuel delivery to maintain the optimal fuel-to-air mixture necessary for efficient combustion. This precise control is crucial for achieving stable turbine performance, reducing emissions, and optimizing fuel consumption.

Constructed with robust materials, the valve is built to withstand the high pressures and temperatures commonly encountered in gas turbine applications. Its durable design ensures long service life and reliable operation even under demanding conditions. The valve features foolproof electrical cables and connectors, enhancing installation safety and reducing the risk of connection errors.

The valve’s compact size and right-angle configuration facilitate straightforward integration into existing turbine fuel systems. Compared to previous models, this valve is an upgrade due to its improved electrical interface and enhanced durability, which reduce maintenance needs and increase operational reliability.

By accurately controlling fuel flow, the 2” Globe-Style Gas Metering Valve helps prevent issues such as flame instability and combustion inefficiency, contributing to smoother turbine operation and lower maintenance costs. It is widely used across various turbine models, including aero-derivative and small- to mid-frame industrial turbines, where precise fuel metering is critical for maintaining performance and compliance with environmental standards.

The Gas Check Valve is a unidirectional valve used in LM2500 gas turbine systems to prevent the reverse flow of combustion gases into critical fuel and oil lines. Its primary function is to maintain the correct flow direction, ensuring that gases only travel toward the combustion chamber and not back into upstream components, where reverse flow could cause damage, safety risks, or system inefficiencies.

This check valve is engineered to operate under the high-pressure and high-temperature conditions typical of industrial gas turbine environments. It serves as a passive safety component, requiring no external power to function, and contributes to the overall reliability and integrity of the turbine system.

Commonly found in aero-derivative gas turbines used in oil and gas applications, the check valve is essential for maintaining proper system performance. Its inclusion in the turbine’s gas path helps ensure safe operation by minimizing the risk of combustion gas contamination in auxiliary systems.