FreeSpin® In-Line Turboexpander

Hydrogen and natural gas are pressurized to facilitate efficient transportation in pipelines across long distances. The gas is depressurized to lower levels using regulating valves for safe delivery through local-distribution networks. The regulator is a simple and generally effective tool for pressure reduction, but significant energy is wasted in this process.

Sapphire Technologies’ FreeSpin® In-line Turboexpander (FIT) uses advanced magnetic technologies that help reduce gas pressure and provide a way to capture the energy lost in pressure reduction. The FIT systems’ generators extract kinetic energy from the pressure reduction at the various stages of gas processing and distribution and allow for the generation of electricity with no added pollution.

The FreeSpin® turboexpander system consists of an integrated high-speed turbine and high-efficiency generator that runs on magnetic bearings in a hermetically sealed, lubrication-free unit to provide more efficient and reliable performance. It can produce up to 300 kW of power and can be configured with multiple units in parallel at a pressure letdown (PLD) station to increase overall output power. With high isentropic efficiency, low capital and lifecycle costs, the FreeSpin™ turboexpander becomes a more viable option than other power generation systems. The affordable, innovative design and reliable components of the FIT enables it to overcome the significant hurdles that have prevented the widespread adoption of turboexpanders in hydrogen and natural gas applications.

The company offers standard or custom-engineered turboexpanders to meet customer requirements in any industry for a range of applications, including:

  • Natural gas pressure letdown (PLD)
  • Hydrogen liquefaction, power generation and distribution


FreeSpin™ In-Line Turboexpander

Variable Speed Drive

FreeSpin™ In-Line Turboexpander

Power Output 125 kW (168 hp) and 300 kW (402 hp)
Rotor Speed 0 to 30,000 rpm
Normalized Flow* 2,000 to 50,000 Nm3/h* (2 to 45 MMSCFD)
Rated Pressure Up to 11.0 MPa-g (1,600 psi-g)
Gas Temperature Range -260 to +120°C (-435 to +250°F)
Hazardous Zone Certification IECEx Certified Hermetic Explosion Proof
Axial Length 1,200 mm (47 in.) Flange to Flange
Diameter 600 mm (24 in.)
Weight Estimate 1,090 kg (2,400 lbs.)

* Normalized condition is 0°C (32°F), 0.1 MPa (14.5 psi)     ** Acceptable flow rate depends on the inlet temperature and pressure

Engineering Support, Installation and Maintenance Services

Sapphire Technologies supports the commissioning process for the company’s FreeSpin® In-line Turboexpander systems after installation, including piping, plumbing and wiring. The commissioning process checks the installation, prepares the unit for start-up, starts the unit and trains the site user on how the system works.

Though there is very little maintenance required for the FreeSpin® system, Sapphire Technologies supports maintenance needs as required. The primary maintenance requirement for the unit is the periodic cleaning of the air filters, which is typically completed by the user. The FreeSpin® turboexpander system can be controlled and diagnosed remotely via the magnetic bearing controller and power electronics.