CPCPGS3053A - DISCONNECT AND RECONNECT SERVICES FROM ‘TYPE A’ GAS APPLIANCES
CONSTRUCTION, PLUMBING AND SERVICE
INTEGRATED FRAMEWORK
TRAINING PACKAGE
CPC08
CPCPGS3053A
DISCONNECT AND RECONNECT SERVICES FROM ‘TYPE A’ GAS APPLIANCES
LEARNING GUIDE
ACKNOWLEDGEMENTS
National Plumbing Services Training Advisory Group
Plumbing Industry Commission Victoria
© Commonwealth of Australia 2015
Construction and Property Services Industry Skills Council
PO Box 151
Belconnen ACT 2616
Tel: 02 6253 0002
This work is copyright, but permission is given to trainers and teachers to make copies and contextualise the resources for use within their own training organisation or in a workplace where training is being conducted. This permission does not extend to making copies for use outside the immediate training environment for which they are made, or the making of copies for hire or resale to third parties.
This work was first published in 2004 with the assistance of funding provided by the Commonwealth Government through the Australian National Training Authority (ANTA). The2015 publication has been updated to reflect changes to the national units of competency.
The views expressed in this work do not necessarily represent the views of the Commonwealth of Australia or CPSISC. In addition, the Commonwealth of Australia and CPSISC do not give warranty or accept any legal liability in relation to the content of this work.
The website addresses and other contact information provided in this publication were compiled in good faith and were correct at the time of printing.
The updating of these resources was completed by:
National Plumbing and Services Training Advisory Group, with funding and support provided by the Construction and Property Services Industry Skills Council (CPSISC):
This guide was developed in consultation with representatives of the Plumbing Industry by NPSTAG and CPSISC to support the implementation of the CPC08 Construction, Plumbing and Services Training Package.
Contents
What is this resource about?......
How do I use this resource?......
Flexible Delivery......
What do I have to do?......
Unit Descriptor......
How will I be assessed?......
Are there any pre-requisites?......
What other resources will I need?......
Texts......
Web sites......
Video or audio cassettes......
Safety......
Introduction......
Properties of gas......
Natural gas......
Liquefied petroleum gas......
Working safely with gas......
Workplace health and Safety......
Properties of gases......
Relative density (RD)......
Combustion principles......
Heating value......
Air requirements......
Products of combustion......
Incomplete combustion of gases......
Avoiding incomplete combustion......
Ignition temperature......
Flammability limits......
Gas pressure and flow rates......
Gas pressure......
Low pressure......
Medium and high pressure......
Factors influencing gas pressures in a distribution system......
Flow rate......
Safety......
Care of the neon test pencil......
Personal protective equipment......
Electrical safety......
Planning work activities......
Planning the disconnection......
Determine job requirements......
Classification of air distribution systems......
Disconnect or reconnect mechanical service equipment......
Isolation of the appliance......
Gas connection......
Electrical connections......
Cold water connections......
Domestic storage water systems......
Instantaneous water heaters......
Hot water boilers......
Ducted heaters......
Flue connections......
Verify job completion......
Reinstalling the appliance......
Supporting the appliance......
Final gas connection......
Hose assemblies......
Commissioning the appliance......
Carry out an electrical safety check......
Electrical connection......
Purging......
Preparing to test burner pressure......
Testing burner pressure......
Adjusting burner pressure......
Checking the pilot flame......
Adjusting pilot flame......
Adjusting aeration......
Demonstrating operation of appliance......
Clean up......
Worksheet
Practical application......
Assessment checklist......
© Commonwealth of Australia 2015 1
CPCPGS3053A - DISCONNECT AND RECONNECT SERVICES FROM ‘TYPE A’ GAS APPLIANCES
What is this resource about?
Welcome to CPCPGS3053A – Disconnect and reconnect services from ‘Type A’ gas appliances. This resource will help you gain the skills and knowledge necessary to demonstrate competence in this unit.
How do I use this resource?
This resource is divided into four main sections:
- A learning unit, which contains background information on CPCPGS3053A – Disconnect and reconnect services from ‘Type A’ gas appliances
- Worksheets, which prepare you for the practical application
- Practical application, which allows you to experience disconnect and reconnect services from ‘Type A’ appliances
- Assessment materials, which help you demonstrate competency.
To complete this unit of competence you will need to:
- read the information contained in the learning unit
- complete the worksheets as instructed
- have your answers checked by your trainer or supervisor
- work with your trainer or supervisor to practise disconnect and reconnect services from ‘Type A’ appliances
- read the assessment checklist together with the assessment sheets
- complete the assessment.
Learning Resources are not intended to be the only source of information nor are they intended to be an exhaustive form of instruction.
Flexible Delivery
The Trainer or Supervisor may adapt and deliver this Learning Resource to suit people from diverse backgrounds to meet equity principles and conform to Legislative policies.
What do I have to do?
To demonstrate competence in this unit you will be required to show the level of skills and knowledge for each of the elements involved in CPCPGS3053A – Disconnect and reconnect services from ‘Type A’ gas appliances. The elements are:
- plan work activities
- determine job requirements
- disconnect or reconnect mechanical service equipment
- verify job completion
- clean up.
If you are unsure of the meaning of these elements you should read the performance criteria on the following page.
To be competent in this unit you will need to demonstrate:
CPCPGS3053A / Disconnect and reconnect Type A gas appliancesUnit Descriptor / This unit of competency specifies the outcomes required to disconnect and reconnect services from Type A gas appliances operating on natural gas (NG), or liquefied petroleum gas (LPG), or tempered liquefied petroleum gas (TLPG) up to 200kPa.
The work is confined to disconnecting and reconnecting a like appliance.
Element / Performance Criteria
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.
1Prepare for work / 1.1Appliance and equipment specifications and appropriate manufacturer manuals are obtained
1.2Work health and safety (WHS) and environmental requirements associated with disconnecting and reconnecting Type A gas appliances are adhered to throughout the work
1.3Quality assurance requirements for company operations are identified and adhered to
1.4Tools, equipmentand materials are selected consistent with disconnecting and reconnecting services, are checked for serviceability, and faults are reported
1.5Appropriate test equipment is selected for the job
1.6Tasks are planned in conjunction with others involved in or affected by the work
2Identify appliance requirements / 2.1Appropriate appliance for gas supply type is selected according to job specification
2.2Appliance installation is checked to ensure its compliance with relevant Australian standards
2.3Appliance is checked for safe operation and its performance is checked against specification
2.4Sustainability principles and concepts are observed when preparing for and undertaking work process
3Disconnect or reconnect equipment / 3.1Electrical safety check is carried out according to state or territory authorities' procedures and statutory and regulatory authorities’ requirements
3.2Safety-check data is recorded in format required by job specification
3.3Appliance is isolated from gas service according to statutory and regulatory requirements
3.4Work is carried out according to job instruction without damage to surrounding equipment or structures
4Test operation of equipment / 4.1Mechanical services, gas, water and other service connections are checked for leaks
4.2Appliance is operated to ensure it conforms to appliance specification
4.3Mechanical services equipment is adjusted according to specification
5Clean up / 5.1Work area is cleared and materials disposed of, reused or recycled according to legislation, regulations, codes of practice and job specification
5.2Tools and equipment are cleaned, checked, maintained and stored according to manufacturer recommendations and workplace procedures
5.3Informationis accessed and documentation completed according to workplace requirements
Required knowledge
/ Required knowledge for this unit is:- application of ignition and combustion principles relating to conveyed materials or materials used in confined work spaces
- electrical safety and requisite precautions
- how to access relevant information, including codes and technical standards
- job safety analysis (JSA) and safe work method statements
- procedures for disconnecting and reconnecting Type A gas appliances
- properties of gas, gas safety, combustion principles, pressure and flow rates
- relevant statutory and authority requirements related to disconnecting and reconnecting Type A gas appliances
- SI system of measurements
- workplace and equipment safety requirements
An up to date version of the ‘Unit Descriptor’ may be located on the Australian Government web site training.gov.au
How will I be assessed?
Your trainer or supervisor will decide with you how you will be assessed. Your assessment activity may include completion of the student worksheet and practical task selected by your trainer or supervisor. Your assessment should allow you to demonstrate all the skills and knowledge required to disconnect and reconnect services from ‘Type A’ appliances.
This unit may be assessed in conjunction with other units of competence. Your trainer or supervisor will tell you if you are to be assessed this way.
Are there any pre-requisites?
Prior to commencing CPCPGS3053A – Disconnect and reconnect services from ‘Type A’ gas appliancesyou must have successfully completed the following pre-requisite:
- CPCPCM2043A - Carry out WHS requirements
Project work may also group pre-requisite and or co-requisite competencies together to carry out such projects. It is recommended that the following competencies are grouped with this unit of competency:
- CPCPGS3058A – Install and commission ‘Type A’ gas appliances.
- CPCPGS3054A – Calculate and install natural ventilation for ‘Type A’ gas appliances.
What other resources will I need?
To assist you the following resources have been suggested and should be available to you to do this competency:
Texts
- AS/NZS5601 -Gas Installations Relevant Version.
- State and Territory regulations may override this Learning Guide.
Web sites
Video or audio cassettes
Safety
Workplace health and safety (WHS) requirements need to be observed in accordance with legislation. You need to know the WHS laws governing your job.
In any work situation you can reduce the risk of injury to yourself and others by using appropriate personal protective equipment (PPE). The types of PPE that you will need include:
Overalls – used for the protection of the installer when working in different conditions
Boots – it is recommended that soft soled footwear is worn while working on roofs, as deep grooved footwear pick up small stones and debris that might damage or scratch the roof sheets
Safety glasses or goggles to protect the eyes from injury when cutting the sheets with a power saw
Ear plugs or muffs to protect the installer’s hearing form excessive noise
Dust masks or respirators to protect the user from breathing in dust or fine particles when cutting the sheets with a power saw
Gloves, for the protection of the installer’s hands when working with different types of pipes, tools and equipment.
Introduction
In this unit you will look at disconnecting and reconnecting services from ‘Type A’ Appliances operating on natural gas, liquid petroleum gas (LPG), simulated natural gas (SNG), tempered liquefied petroleum (TLP) or town gas (TG).
The disconnection and reconnection of gas appliances is the removal and then the replacement of a gas appliance for any of the following reasons:
- changing to a new appliance
- relocate the existing appliance
- cleaning purpose
- servicing
- alteration to any of the connected plumbing services, including flues, gas, water, (hot and cold), mechanical services, (ducting, water heating piping).
The type of gas appliance that you could be disconnecting and reconnecting would include any domestic gas appliance such as:
- cookers
- hot water services
- space heaters
- ducted heaters
- swimming pool heaters.
In the commercial area it would include appliances used for:
- cooking
- heating
- hot water
- heating in hotels, restaurants, shops, small factories.
Before you can begin to disconnect and reconnect services from ‘Type A’ gas appliances, you should have knowledge of the following:
- properties of gas, gas safety
- ignition and combustion principles of conveyed materials or materials used in confined work spaces
- gas pressure and flow rates
- electrical safety
- classification of air distribution systems.
Properties of gas
Gas is used widely throughout the world as a fuel, and comes in two basic forms, natural or manufactured. In Australia gas is marketed in four different forms. They are:
- natural gas (NG)
- liquefied petroleum gas (LPG)
- tempered Liquefied Petroleum (TLP)
- simulated Natural Gas (SNG).
Natural gas
Natural gas (Methane) consists of approximately 75 to 95 per cent Methane
(a combination of hydrogen and carbon) and is the most widely used gas in Australia.
Liquefied petroleum gas
Liquefied petroleum gas (Propane) or LPG is obtained from two sources. Firstly, it is made by oil refineries during the processing of crude oil into petrol; some of the by-products are gaseous hydrocarbons, two of which are butane and propane.
Secondly it comes with the extraction of crude oil and natural gas from the ground. The gases are separated for the crude oil when it comes ashore and is piped off to a gas processing plant for distribution as NG or LPG for gas appliances which is normally almost pure propane. LPG for vehicle use is a mixture of both butane and propane and should not be used with gas burning appliances.
Both these gases can be liquefied by either refrigeration or moderate pressure, which makes it easy to transport and storage. The LPG returns to a gaseous state when the pressure is released.
Other forms of gas that you will occasionally be required to deal with are:
tempered liquefied petroleum gas (TLPG)
- simulated natural gas (SNG)
- town gas (TG).
Tempered liquefied petroleum gas or TLPG, is made very simply and efficiently from LPG in a small and relatively inexpensive plant which mixes LPG with air in very controlled proportions. TLPG is used as a substitute for town gas.
Simulated natural gas or SNG is made in virtually the same way as TLPG. Air is mixed with LPG. Then a combination of other gases is used to alter the burning properties for the gas to simulate natural gas.
TLPG and SNG gases are odourless and non-toxic in their natural state, so an odourent has to be added. It is however possible to suffocate in a confined space where large amounts of the gases may gather.
Town Gas or TG is gas made from either black or brown coal. The coal is roasted at high temperatures which causes the coal to give off a gas which is collected and stored in holders for use as town gas. This form of gas is no longer in use in Australia.
Working safely with gas
Revision of CPCPCM2043A - Carry out WHS requirements, before commencing this unit is advisable
Working safely with gas requires you to be responsible whenever a gas escape or a dangerous gas installation is found.
AS/NZS5601 - Gas installments (relevant version)clauses 2.10 and 2.11 deal with the procedure you must follow when a gas leak occurs and or you find a faulty appliance installation.
Most accidents in the gas industry are caused by unsafe acts or unsafe conditions.
Unsafe acts include:
- incorrect testing of gas lines
- looking for gas escapes with a naked flame
- working on live gas lines without proper equipment
- installing gas appliance flues incorrectly
- working on gas appliances without safety glasses.
Unsafe conditions include:
- gas escapes
- poorly ventilated rooms in which gas appliances are used
- incorrectly installed appliances
- over gas rated appliances
- faulty safety devices
- accumulation of both unburnt and burnt gases
- unburnt gases are a potential source of danger in the form of:
explosions
fires
asphyxiation from the lack of air
with burnt gases the danger is from asphyxiation from either carbon monoxide or carbon dioxide.
WorksheetNow go to the Worksheet and answer Questions 1 – 8.
Workplace health and Safety
WHS provisions aim to protect workers from the hazards they are exposed to in the workplace. You need to carry out a risk assessment in order to be equipped with the correct personal protective equipment (PPE) and electrical safety apparatus before installing appliances. You need to use safe techniques for manual handling appliances and remember that lifting equipment may be required.
The PPE that may be required for the disconnect and reconnect services from ‘Type A’ appliances includes:
- overalls
- boots
- gloves
- safety glasses or goggles
- dust masks or respirators
- hard hats.
Properties of gases
For the four types of gases you are likely to encounter in gas work, each gas has characteristics or differences you must be aware of to work safely with each gas.
The table below gives the different properties of the gases above including acetylene.
Relative density air = 1 / 0.6 / 1.55 / 1.12 / 0.6 to1.2 / 0.6
Heat Value mJ/m³ / 37.4 / 95.31 / 24.7 / 37 to 48 / 20.5
Volumes of air to burn completely one volume of gas / 10 / 25 / 6 / 9 to 10 / 4.5
Flammable limits / 5% to 14% / 2.5% to 9.5% / 2.5% to 9.5% / 2.5% to 9.5% / 5% to 40% / 2.5% to 80%
Ignition temperature °C / 680 to 750 / 510 to 580 / 510 to 580 / 510 to 580 / 550 / 400
Relative density (RD)
Every substance has weight or ‘mass’, including gas. To compare weights of gases a comparison is made between the ‘density’ or weight of a given volume of gas and the same volume of air.
Air is the standard used to measure all other gases against, air has a relative density of 1.0.
Gas with a ‘RD’ less then this will be lighter than air and will rise, eg (NG 0.6) and dissipate into the surrounding air, whereas gases with a RD more than 1.0 will be heavier than air (LPG 1.55) and will sink and collect in low areas.