This standard specifies a basic series of parameters that characterize low-pressure turbine expanders. This standard is mainly used for centripetal turbine expanders (hereinafter referred to as "expanders") that use expansion to obtain cooling capacity during processes such as air separation and liquefaction, and the inlet pressure is not greater than 1.6MPa. Other types of radial turbine expanders can be implemented by reference. The pressures involved in this standard are absolute pressures.