Unit of competency details

Unit descriptor 

This unit of competency specifies the outcomes required to purge consumer gas piping systems.

Application of the unit 

Site location for work application may be either domestic or commercial, and may be a new work site or an existing structure being renovated, extended, restored or maintained.

Prerequisite units 

CPCPCM2023A

Carry out OHS requirements

Employability skills 

This unit contains employability skills.

Elements describe the essential outcomes of a unit of competency.

Performance criteria describe the performance needed to demonstrate achievement of the element. Where bold italicised text is used, further information is detailed in the required skills and knowledge section and the range statement. Assessment of performance is to be consistent with the evidence guide.

ELEMENT 

PERFORMANCE CRITERIA 

1. Prepare for purging.

1.1. Design drawing and specification are obtained.

1.2. Safety  (OHS ) requirements associated with purging consumer gas piping systems, and workplace environmental requirements , are adhered to throughout the work.

1.3. Quality assurance  requirements for company operations are identified and adhered to.

1.4. Work is planned in conjunction with others involved in or affected by the work.

1.5. Appropriate tools and equipment  for the conduct of purging , including personal protective equipment, are identified, selected and checked for serviceability.

1.6. Work area and materials  are prepared to support efficient purging of consumer gas piping system.

2. Identify purge requirements.

2.1. Installation is checked to ensure compliance with standards and relevant specifications.

2.2. Volume of piping system is determined from design drawing and standards, and calculations are recorded in format required by job specification.

2.3. Method of purging is selected in compliance with standards and authorities' requirements.

2.4. Purge medium is selected in compliance with standards, and calculations of the purge medium volume are recorded in format required by job specification.

3. Carry out and test purge operation.

3.1. Outlet point for purge gas is located and purge site is checked for ignition sources.

3.2. Purge is carried out in accordance with standards or statutory and regulatory authority  requirements.

3.3. Completion of purge is verified by test equipment, or by recognised and approved workplace testing procedures.

4. Clean up.

4.1. Work area is cleared and materials disposed of or recycled in accordance with state and territory legislation and workplace procedures.

4.2. Tools and equipment are cleaned, checked, maintained and stored in accordance with manufacturer recommendations and workplace procedures.

4.3. Information  is accessed and documentation completed in accordance with workplace requirements.

REQUIRED SKILLS AND KNOWLEDGE 

This section describes the skills and knowledge required for this unit.

Required skills 

Required skills for this unit are:

• communication skills to:

• access information
• complete workplace documentation
• determine requirements
• enable clear and direct communication, using questioning to identify and confirm requirements, share information, listen and understand
• follow instructions
• inform relevant authorities and supervisors of completion of job
• plan work with others
• read and interpret:

• documentation from a variety of sources
• drawings and specifications

• record data in writing
• use language and concepts appropriate to cultural differences
• use and interpret non-verbal communication, such as hand signals

• determining purging requirements of a consumer gas piping system in terms of volume, method and medium of purge
• conducting purging and testing for its completeness
• identifying and accurately reporting to appropriate personnel any faults in tools, equipment or materials
• numeracy skills to apply measurements and calculations
• organisational skills, including the ability to plan and set out work
• teamwork skills to work with others to action tasks and relate to people from a range of cultural and ethnic backgrounds and with varying physical and mental abilities
• technological skills to:

• access and understand site-specific instructions in a variety of media
• use mobile communication technology.

Required knowledge 

Required knowledge for this unit is:

• characteristics of materials used in the purging process
• effect of heat on the materials used during the purging and testing process
• electrical safety and requisite precautions
• how to access relevant information, including codes and technical standards
• job safety analysis (JSA) and safe work method statements (SWMS)
• procedures for purging gas piping systems, including isolation processes and procedures
• properties of gas, gas safety, combustion principles, ignition principles, pressure and flow rates
• relevant statutory and authority requirements related to purging gas piping systems
• SI system of measurements
• workplace and equipment safety requirements.

EVIDENCE GUIDE 

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 

This unit of competency could be assessed in the workplace or a close simulation of the workplace environment providing that simulated or project-based assessment techniques fully replicate plumbing and services workplace conditions, materials, activities, responsibilities and procedures.

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

A person who demonstrates competency in this unit must be able to provide evidence of:

• locating, interpreting and applying relevant information, standards and specifications for determining requirements, and purging and testing consumer gas piping systems
• applying safety requirements throughout the work sequence, including the use of personal protective clothing and equipment and the elimination of possible ignition sources
• as a minimum the ability to, given the plans and specifications, conduct purging, testing and recording of the purge operations (one to be a fuel and inert purge and the other to be an inert and fuel purge) for a consumer gas piping system of greater than 0.03 cubic metres, which includes a subsidiary meter, ensuring:

• correct identification of method, medium, calculations and procedures to purge the piping system
• correct selection and use of appropriate processes, tools and equipment
• completing all work to specification
• compliance with regulations, standards and organisational quality procedures and processes
• communicating and working effectively and safely with others.

Context of and specific resources for assessment 

This competency is to be assessed using standard and authorised work practices, safety requirements and environmental constraints.

Assessment of essential underpinning knowledge will usually be conducted in an off-site context.

Assessment is to comply with relevant regulatory or Australian standards' requirements.

Resource implications for assessment include:

• an induction procedure and requirement
• realistic tasks or simulated tasks covering the minimum task requirements
• relevant specifications and work instructions
• tools and equipment appropriate to applying safe work practices
• support materials appropriate to activity
• workplace instructions relating to safe working practices and addressing hazards and emergencies
• material safety data sheets
• research resources, including industry related systems information.

Reasonable adjustments for people with disabilities must be made to assessment processes where required. This could include access to modified equipment and other physical resources, and the provision of appropriate assessment support.

Method of assessment 

Assessment methods must:

• satisfy the endorsed Assessment Guidelines of the Construction, Plumbing and Services Training Package
• include direct observation of tasks in real or simulated work conditions, with questioning to confirm the ability to consistently identify and correctly interpret the essential underpinning knowledge required for practical application
• reinforce the integration of employability skills with workplace tasks and job roles
• confirm that competency is verified and able to be transferred to other circumstances and environments.

Validity and sufficiency of evidence requires that:

• competency will need to be demonstrated over a period of time reflecting the scope of the role and the practical requirements of the workplace
• where the assessment is part of a structured learning experience the evidence collected must relate to a number of performances assessed at different points in time and separated by further learning and practice, with a decision on competency only taken at the point when the assessor has complete confidence in the person's demonstrated ability and applied knowledge
• all assessment that is part of a structured learning experience must include a combination of direct, indirect and supplementary evidence.

Assessment processes and techniques should as far as is practical take into account the language, literacy and numeracy capacity of the candidate in relation to the competency being assessed.

Supplementary evidence of competency may be obtained from relevant authenticated documentation from third parties, such as existing supervisors, team leaders or specialist training staff.

RANGE STATEMENT 

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.

Safety  (OHS ) is to be in accordance with commonwealth, state and territory legislation and regulations and may include:

• handling of materials
• hazard control
• personal protective clothing and equipment prescribed under legislation, regulations and workplace policies and practices
• safe operating procedures, including recognising and preventing hazards associated with:

• hazardous materials and substances
• service lines
• surrounding structures and facilities
• trip hazards
• use of tools and equipment
• work site visitors and the public
• working at heights
• working in proximity to others

• use of firefighting equipment
• use of first aid equipment
• workplace environment and safety.

Environmental requirements  include:

• clean-up protection
• waste management.

Quality assurance  requirements may include:

• Australian standards
• Environment Protection Authority (EPA)
• internal company quality assurance policy and risk management strategy
• International Standards Organisation
• site safety plan
• workplace operations and procedures.

Tools and equipment  may include:

• barriers
• buckets
• gas analyser
• hand and power tools
• ladders
• purge stacks
• restricted height scaffolding
• signs
• testing equipment.

Purging :

• may occur before commencing work and on completion of work using either air, fuel gas or an inert gas on pipe volumes up to and exceeding 0.03 cubic metres, to applicable regulatory requirements
• installation to be purged, calculations, method, medium and conduct of purging is to conform to standards or requirements of local regulatory authority
• methods of purging are to include:

• fuel and inert purge
• inert and fuel purge.

Materials  for purging may include:

• purging media of air, nitrogen, carbon dioxide or fuel gas.

Statutory and regulatory authorities  include:

• state or territory statutory authority
• statutory gasfitting authority
• statutory plumbing authority.

Information  may include:

• charts and hand drawings
• diagrams or sketches
• instructions issued by authorised organisational or external personnel
• job drawings
• manufacturer specifications and instructions
• material safety data sheets (MSDS)
• memos
• organisation work specifications and requirements
• regulatory and legislative requirements, particularly those pertaining to:

• building codes
• OHS and environmental requirements
• plumbing and gasfitting authority regulations

• recognised formulas or tables accepted by the regulatory authority
• relevant Australian standards
• safe work procedures relating to purging and testing consumer gas piping systems
• signage
• verbal, written and graphical instructions
• work bulletins
• work schedules, plans and specifications.

Unit sector 

Plumbing and services

Co-requisite units 

Nil

Functional area