These high-speed rotating Turboexpander-Compressor machines are typically used in cryogenic applications including natural gas, petrochemical, and air separation industries. As high pressure gas is expanded across the turbine, the majority of the energy potential in the gas is extracted and transferred through the shaft and to the compressor. The resultant pressure reduction combined with efficient energy extraction produces the refrigeration necessary for cryogenic gas processing. The power extracted can then be used elsewhere in the process, such as a booster compressor. The efficiency inherent in the Turboexpander-Compressor makes it the preferred turboexpander for natural gas and cryogenic gas processing within the petrochemical industry and other industrial processes requiring refrigeration.