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.

Evidence required to demonstrate competence in this unit must be relevant to and satisfy the requirements of the elements and performance criteria, and include the ability to:

start up/shut down the Joule-Thomson system

monitor the system

recognise early warning signs of equipment/processes needing attention or with potential problems

determine the most likely cause of routine problems

take appropriate action to ensure a timely return to full performance

isolate and de-isolate equipment

identify hazards and apply hazard control procedures.

Evidence must be provided that demonstrates knowledge of:

cryogenic hazards associated with the process and the materials, including metal embrittlement

cryogenic materials, their lines and vessels

Joule-Thomson principles

physics relevant to Joule-Thomson system, including Boyles and Charles laws, adiabatic/constant enthalpy expansion, inversion temperature and product dew point (i.e. dew point of the hydrocarbon, air or other gas being condensed)

importance of the temperature range, (lack of) moisture (and other contaminants) in the process stream, and other critical variables

hierarchy of control

hazards that may arise in the job/work environment, and:

their possible causes

potential consequences

appropriate risk controls.

The unit should be assessed holistically and the judgement of competence based on a holistic assessment of the evidence.

The collection of performance evidence:

should occur over a range of situations which include typical disruptions to normal, smooth operation of an operating plant

will typically include a supervisor/third-party report or other evidence, focusing on consistent performance and problem recognition and solving. A supervisor/third-party report must be prepared by someone who has a direct, relevant, current relationship with the person being assessed and who is in a position to form a judgement on workplace performance relevant to the unit of competency

must include the use of an appropriate industrial item of equipment requiring demonstration of operation, start-up and shutdown procedures and responding to problems

may use industry-based simulation for part only of the unit where safety, lack of opportunity or significant cost is an issue.

Assessment should occur in operational workplace situations. Where this is not possible, or where personal safety or environmental damage are limiting factors, assessment must occur in a sufficiently rigorous simulated environment reflecting realistic operational workplace conditions. This must cover all aspects of workplace performance, including environment, task skills, task management skills, contingency management skills and job role environment skills.

Assessment in a simulated environment should use evidence collected from one or more of:

walk-throughs

pilot plant operation

demonstration of skills

industry-based case studies/scenarios

‘what ifs’.

Knowledge evidence may be collected concurrently with performance evidence (provided a record is kept) or through an independent process, such as workbooks, written assessments or interviews (provided a record is kept).

Assessment processes and techniques must be appropriate to the language, literacy and numeracy requirements of the work being performed and the needs of the candidate.

Conditions for assessment must include access to all tools, equipment, materials and documentation required, including relevant workplace procedures, product and manufacturing specifications associated with this unit.

The regulatory framework will be reflected in workplace policies and procedures and is not required to be independently assessed.

Foundation skills are integral to competent performance of the unit and should not be assessed separately.

Assessors must satisfy the assessor competency requirements that are in place at the time of the assessment as set by the VET regulator.

In addition, the assessor or anyone acting in subject matter expert role in assessment must demonstrate both technical competency and currency. If the assessor cannot demonstrate technical competency and currency they must assess with a subject matter expert who does meet these requirements.

Technical competence can be demonstrated through one or more of:

relevant VET or other qualification/Statement of Attainment

appropriate workplace experience undertaking the type of work being assessed under routine and non-routine conditions

appropriate workplace experience supervising/evaluating the type of work being assessed under routine and non-routine conditions

Currency can be demonstrated through one or more of:

being currently employed undertaking the type of work being assessed

being employed by the organisation undertaking the type of work being assessed and having maintained currency in accordance with that organisation’s policies and procedures

having consulted/had contact with an organisation undertaking the type of work being assessed within the last twelve months, the consultation/contact being related to assessment

conducting on-the-job training/assessments of the type of work being assessed

being an active member of a relevant professional body and participating in activities relevant to the assessment of this type of work.

This section describes those language, literacy, numeracy and employment skills that are essential to performance.

Foundation skills essential to performance are explicit in the performance criteria of this unit of competency.

Operations