FreeSpin® is a turboexpander-generator runs on pressure, consumes no water or fuel, and generates zero greenhouse gas emissions.

Hermetically sealed enclosure
No water, oil required
No-combustion pressure conversion
Sapphire Technologies’ FreeSpin® In-line Turboexpander (FIT) is a turboexpander-generator system that uses advanced magnetic technologies to recover the energy lost in pressure reduction processes.
FIT converts the kinetic energy of a fluid into rotational energy, enabling the generation of electricity with no added pollution.

Pressure energy recovery uses zero fuel and produces zero emissions. The system is hermetically sealed inside a single housing and does not utilize dynamic seals, which often cause environmental hazards upon failure.
FIT runs on active magnetic bearings which eliminate the need for a gearbox and a lubrication system. These bearings offer significant advantages over conventional bearings in terms of operating efficiency, remote monitoring capabilities, power consumption, and reliable performance in harsh environments.
The high-speed permanent magnet generator is simply constructed and operates with very little losses. It has variable speed and load capabilities and provides greater power density and a smaller footprint than conventional generator systems.
FIT’s control system uses artificial intelligence to analyze thousands of sensor inputs per second and safely operate the permanent magnet generator. Output data informs predictive insights that reduce failure risk and support smarter asset management.


The inlet guide vanes direct gas-flow toward the expander wheel at the optimal angle. These are designed much like a water wheel, but the concentric cavity gradually increases in cross section from inlet to outlet allowing for expansion of the gas. Radial turboexpanders are designed with axial flow inlets and radial flow outlets such that the gas is expanded radially through the turbine wheel.
High pressure gas enters through the expander wheel where the kinetic energy is extracted from the gas stream. The gas leaves the expander wheel at a lower pressure and temperature. The turbine wheels are typically designed to optimize aero efficiency. Application variables affecting turbine wheel design include inlet/outlet temperature, inlet/outlet pressure, volumetric flow rate and fluid characteristics. When the pressure ratio is too large to reduce through a single stage, multi-stage turboexpanders are required.
The permanent magnet synchronous generator is utilized in a high-speed, direct-drive turboexpander for power generation. The permanent magnet (PM) generator in the FreeSpin® In-line Turboexpander is directly coupled to the turbine shaft and converts the rotational mechanical energy from the turbine into useable electricity via the variable speed drive. The direct-drive, permanent-magnet generator has variable speed and load capabilities and can run at speeds up to 30,000 rpm. The patented technology also offers high-speed operation, simplified controls for power generation and no maintenance.
The PM generator consist of two basic parts. A stator coil powered by an alternating current to create an electric field and a rotor made of special magnetic material that rotates within that field. The high-speed PM generators utilize the latest technology in high-strength rare-earth magnetic materials to achieve high efficiency and a high-power density. In comparison to other generator types, the PM generator has higher efficiency therefore improving the overall system efficiency and has higher power density allowing for a compact size at all power levels.
The magnetic bearings in the FreeSpin® turboexpander are highly reliable, reduce operating costs and expand machine operating parameters. An AMB allows the dynamic components of the FIT to operate in a levitated condition, consuming very little energy and eliminating maintenance as compared to conventional bearings. The AMBs are controlled by magnetic bearing controller, which controls and monitors conditions of the AMB system, allowing complete control of the system and adaptive control under varying load conditions.
The AMBs have built-in diagnostics capabilities that provide users with insight into the generator’s health and performance by monitoring axial and radial load conditions. With a connection to the computer, identifying, analyzing and archiving the health and historical performance of the machine are all possible remotely. This protects the machine and provides process characteristics enabling diagnostics of the gas flow. The graphical user interface (GUI) provides insight into all aspects of magnetic bearing and machine performance and can be utilized to view real-time data, such as changes in mass flow, temperature of internally powered components and density without any additional equipment.
Sapphire Technologies’ service team supports the field installation and commissioning of FIT.
During commissioning, our technicians and engineers will verify all aspects of FIT installation and prepare the system for start-up. The system will be tuned to factory specifications and the operator will be trained on system operation.
Though there is little maintenance required for FIT, Sapphire Technologies supports field maintenance requests as required. Remote monitoring capabilities allow for maintenance issues to be diagnosed and resolved quickly.

A turboexpander-generator converts pressure energy into usable electricity and cooling. In FreeSpin®, high-pressure gas expands through a turbine wheel that drives a generator, while the expansion process also creates a low-temperature fluid that can be used in heat exchange processes.
FreeSpin® runs on pressure already present in gas infrastructure. It does not require additional fuel, consumes no water, and generates electricity through a no-combustion process. That makes it a practical way to recover energy that would otherwise be lost during normal pressure reduction.
As gas expands through the turboexpander, pressure energy is converted into rotational energy to drive the generator. At the same time, the gas cools rapidly during expansion, creating a low-temperature fluid stream that can be integrated into facility heat exchange processes.
FreeSpin® is a strong fit when a project has access to gas infrastructure and needs fast-to-deploy on-site power, integrated cooling, improved site efficiency, or a way to get more value from existing pressure drop. It is especially relevant for data centers, industrial facilities, and other sites where speed to power, cooling performance, and operating cost matter.