The Evidence Guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Overview of assessment

Critical aspects for assessment and evidence required to demonstrate competency in this unit

It is essential that the equipment be understood and that the importance of critical properties, settings and readings is known. Competence must be demonstrated in the operation of all ancillary equipment to the level required for this unit of competency.

Competence must be demonstrated in the ability to recognise and analyse potential situations requiring action and then in implementing appropriate corrective action.

Consistent performance should be demonstrated. In particular look to see that:

hazards are identified and controlled

product properties are kept within limits

quality is monitored to minimise wastage

process measurements/observations are continually made

all HSE requirements are followed

problems are anticipated and appropriate action is taken (i.e. problem fixed or reported).

Context of and specific resources for assessment

Assessment of this unit should include demonstrated competence on actual plant and equipment in a work environment. The unit will be assessed in as holistic a manner as is practical and may be integrated with the assessment of other relevant units of competency. Assessment will occur over a range of situations, which will include disruptions to normal, smooth operation.

Simulation may be required to allow for assessment of parts of this unit. Simulation should be based on the actual plant and include walk-throughs of the relevant competency components. Simulations may also include the use of case studies/scenarios, role plays and 3D virtual reality interactive systems. In the case of evacuation training or training for competencies practised in life-threatening situations, simulation may be used for the bulk of the training.

A bank of scenarios/case studies/what-ifs and questions will be required to probe the reasoning behind observable actions.

Method of assessment

In all plants it may be appropriate to assess this unit concurrently with relevant teamwork and communication units.

Individual enterprises may choose to add prerequisites and co-requisites relevant to their processes.

Guidance information for assessment

Assessment processes and techniques must be culturally appropriate and appropriate to the language and literacy capacity of the candidate and the work being performed.

Required skills

Required skills include:

recognising conditions which will lead to out of specification product or unsafe situation

implementing the enterprise's procedures within time constraints and in a manner relevant to the correct use of the equipment

conveying information relevant to the operation clearly and effectively

maintaining appropriate levels of quality assurance

reading and numeracy to interpret workplace documents, instrumentation and technical information

Required knowledge

Required knowledge includes:

hazards associated with the process

cryogenic hazards associated with the process and the materials

cryogenic materials, their lines and vessels

metal embrittlement

application of the hierarchy of control in controlling the hazards

Joule-Thomson principles

adiabatic/constant enthalpy expansion, inversion temperature

principles of operation of particular devices installed on plant

importance of the temperature range (and other critical variables)

gas properties (Boyles and Charles laws)

product dew point (i.e. dew point of the hydrocarbon, air or other gas being condensed)

importance of (lack of) moisture (and other contaminants) in the process stream

consequences of deviations from the desired values of critical variables

safe start-up from different conditions (e.g. warm vs cold starts)

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Procedures

All operations are performed in accordance with standard procedures. Procedures may be written, verbal, computer-based or in some other form. They include:

all work instructions

standard operating procedures

formulas/recipes

batch sheets

temporary instructions

any similar instructions provided for the smooth running of the plant

For the purposes of this Training Package, 'procedures' also includes good operating practice as may be defined by industry codes of practice (e.g. Responsible Care) and government regulations

Joule-Thomson device

A Joule-Thomson device is any device which requires a gas/vapour to do work, typically by expanding, so cooling the vapour (i.e. uses the Joule-Thomson effect). While the vapour will not usually condense in the Joule-Thomson device it will often condense immediately on leaving the device. Some devices may be constructed to allow for condensation to occur within the device, this is sometimes also called the Joule-Kelvin effect

Hazards

Hazards include:

process hazards

cryogenic materials

cryogenic hazards

cold embrittlement

other hazards

Product produced

Product produced will typically be monitored for:

value of critical variables

state (liquid/vapour)

production rate (e.g. volume or mass flow rate)

other properties

Critical variables

Critical variables will typically include:

temperature

pressure

pressure drops

purity/contaminants

and may include:

inlet guide vane (IGV) blade angles

speed of rotation

other variables

Support units

Support units include:

lubricating oil

dry gas seals

other seals

other units

Ancillary equipment

This unit also covers ancillary equipment which forms part of the Joule-Thomson system

Appropriate action

Appropriate action includes:

recognising actual and potential problems

determining problems needing action

determining possible fault causes

rectifying problem using appropriate solution within area of responsibility

following through items initiated until final resolution has occurred

reporting problems outside area of responsibility to designated person

Start up/shut down as required

Start up/shut down as required includes:

start up and shut down to/from normal operating conditions

start up and shut down to/from isolated, cold and empty

all other conditions experienced on the plant (i.e. from any condition to any condition experienced on the plant)

Health, safety and environment (HSE)

All operations to which this unit applies are subject to stringent HSE requirements, which may be imposed through state, territory or federal legislation, and these must not be compromised at any time. Where there is an apparent conflict between Performance Criteria and HSE requirements, the HSE requirements take precedence