This unit of competency covers the skills and knowledge required to operate a range of equipment generally covered by the title 'Joule-Thomson device'. This unit of competency covers all Joule-Thomson type devices, such as turbo expanders, expansion turbines and expansion engines. These devices are typically encountered in any cryogenic process and are a critical part of the 'cold end' or refrigeration cycle. This unit of competency applies to operators who are required to start up and shut down the equipment, monitor its performance, identify operational problems and take appropriate action, and maintain records. Generally any adjustment to the Joule-Thomson device will be made remotely by the control panel operator.In a typical scenario, an operator monitors and operates a cryogenic plant which liquefies hydrocarbons, air or other gas. The purpose of the liquefaction may be to then separate the components by distillation or other means, or there may be other reasons for liquefying the gas (e.g. to reduce volume for shipping). The gas being liquefied may also be the refrigerant fluid used for at least part of the cooling/liquefaction cycle. This may be undertaken in conjunction with other refrigeration and/or cooling processes.This unit of competency applies to an individual who may work alone although under routine direction and supervision. They may work as part of a team or group and will work in liaison with other shift team members and the control room operator, as appropriate. The operator will typically operate the entire cooling and liquefaction operation and so will also be operating a compressor, a heat exchanger and a dryer. No licensing, legislative or certification requirements apply to this unit at the time of publication.