CPCPGS3046A - INSTALL LPG SYSTEMS IN CARAVANS, MOBILE HOMES AND MOBILE WORKPLACES


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). The 2015 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 to be altered to suit.

What is this resource about?......

How do I use this resource?......

Flexible Delivery......

What do I have to do?...... 1

Unit Descriptor...... 2

Element...... 2

Performance Criteria...... 2

How will I be assessed?...... 4

Are there any pre-requisites?...... 4

What other resources will I need?...... 4

Texts...... 4

Safety...... 5

Workplace environment and safety...... 5

Introduction...... 6

Properties of LPG...... 7

Ignition and combustion principles...... 9

Gas combustion...... 10

Complete combustion...... 10

Incomplete combustion...... 10

Chilling a gas flame...... 11

Safety...... 11

Electrical safety...... 12

Regulations...... 12

Quality assurance...... 13

Planning...... 14

Other considerations...... 14

Personal protective equipment...... 15

Choosing the right tools...... 15

Determining LP gas system requirements...... 16

Determine the gas load...... 17

Calculate the storage capacity...... 17

Calculate the regulator size and any connections...... 19

Conversions...... 20

Pigtail connections...... 20

AS/NZS5601 Details requirements for caravans and catering vehicles...... 21

Checking the location and set out...... 21

Cylinder requirements...... 21

Cylinder installation...... 21

Location of a cylinder...... 21

Cylinder in a compartment...... 23

Cylinder regulator...... 24

Consumer piping...... 25

Restriction on pipe joints...... 26

Restriction on hose assemblies used as consumer piping...... 26

Consumer instruction labels and plates...... 26

Appliance installation...... 26

General...... 26

Prohibited appliances...... 27

Required clearance between appliance and fuel filler cap vent or vent...... 27

Water Heaters...... 29

Flued appliances...... 30

Air supply to appliances...... 30

Worksheet...... 32

Practical application...... 37

Assessment checklist...... 38

1

© Commonwealth of Australia 2015

CPCPGS3046A - INSTALL LPG SYSTEMS IN CARAVANS, MOBILE HOMES AND MOBILE WORKPLACES

What is this resource about?

Welcome to CPCPGS3046A – Install LPG systems in caravans, mobile homes, and mobile workplaces. 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 CPCPGS3046A – Install LPG systems in caravans, mobile homes, and mobile workplaces
  • Worksheets, which prepare you for the practical application
  • Practical application, which allows you to experience installing LP gas systems in caravans, mobile homes, and mobile workplaces
  • 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 practiceinstalling LP gas systems in caravans, mobile homes, and mobile workplaces
  • 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 required level of skills and knowledge for each of the elements involved in CPCPGS3046A – Install LPG systems in caravans, mobile homes, and mobile workplaces:

  • Plan work activities
  • Determine LP gas system requirements
  • Install system
  • Test and commission system
  • Clean up.

If you are unsure of the meaning of these elements you should read the performance criteria on the following page.

CPCPGS3046A / Install LPG systems in caravans, mobile homes, and mobile workplaces
Unit Descriptor / This unit of competency specifies the outcomes required to determine the requirements for installing and commissioning liquefied petroleum gas (LPG) systems with an operating pressure not exceeding 2.75kPa in caravans, mobile homes and mobile workplaces
Element / Performance Criteria
Elements define 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
1 / Identify LPG system requirements. / 1.1 / Plans, specifications and any special instructions are obtained.
1.2 / Work health and safety (WHS) and environmental requirements associated with installing and commissioning LPG systems in caravans, mobile homes and mobile workplaces are adhered to throughout the work.
1.3 / Quality assurance requirements for company operations are identified and adhered to.
1.4 / Gas load and design requirements are determined from plans, specifications, and job drawing or workplace instructions.
1.5 / System capacity is calculated to ensure adequacy for the required load and compliance with relevant Australian standards and installation requirements.
1.6 / Appropriate regulator and piping are identified in terms of size, connection sizes and capacity, according to relevant Australian standards and installation requirements.
1.7 / Location of cylinders, appliances and piping set out is identified according to job requirements and in compliance with relevant Australian standards and installation requirements.
1.8 / Quantity of piping, components and fittings is estimated in compliance with relevant Australian standards and installation requirements.
2 / Prepare for installation. / 2.1 / Materials, equipment, appliances and cylinders are ordered and checked for compliance with docket and order form, and for acceptable condition.
2.2 / Appropriate tools and equipment for installing and commissioning LPG systems in caravans, mobile homes and mobile workplaces, including personal protective equipment, are identified and selected.
2.3 / Work is planned in conjunction with others involved in or affected by the work.
2.4 / Work area and materials are prepared to support efficient installation of the system.
2.5 / Sustainability principles and concepts are observed when preparing for and undertaking work process.
3 / Install LPG system, including flue and ventilation. / 3.1 / Cylinders, regulators, associated pipework, appliances and fixings are installed in compliance with manufacturer requirements, relevant Australian standards and installation requirements.
3.2 / Ventilation requirements are determined and installed according to relevant Australian standards.
4 / Test and commission LPG system. / 4.1 / Appropriate test equipment is selected.
4.2 / System is tested according to relevant Australian standards and manufacturer requirements.
4.3 / System is commissioned according to relevant Australian standards and manufacturer requirements.
4.4 / Test data is recorded in format required by regulatory and installation requirements.
4.5 / Compliance plates and signage are located and fitted according to statutory and regulatory authorities’ requirements, relevant Australian standards and installation requirements.
5 / Clean up. / 5.1 / Work area is cleared and materials disposed of, reused or recycled according to legislation, regulations, codes of practice and job specification.
5.2 / Tools and equipment are cleaned, checked, maintained and stored according to manufacturer recommendations and workplace procedures.
5.3 / Information is accessed and documentation completed according to statutory requirements.

Required knowledge

/
  • 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)
  • process for determining material requirements
  • procedures for installing and commissioning gas systems in caravans, mobile homes and mobile workplaces
  • properties of gas, gas safety, combustion principles, gas pressures, and cylinder installation and ventilation requirements
  • relevant statutory requirements related to installing LPG systems
  • 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 install LP gas systems in caravans, mobile homes, and mobile workplaces.

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 CPCPGS3046A – Install LPG systems in caravans, mobile homes, and mobile workplacesyou must have successfully completed the following pre-requisite:

  • CPCPCM2043A – Carry out WHS requirements

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/NZS 5601 part 1 and 2 Gas Installations(relevant version)
  • AS/NZS1596 – 2000 Storage and handling of LP gas
  • State or Territory regulations may override this learning guide.

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. Revision of CPCPCM2043A – Carry out WHS requirements, before commencing this unit is advisable.

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 may require:

  • 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 from 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.

Workplace environment and safety

Handling of materials / Manual lifting and handling techniques must always be followed according to WHS requirements. You should move materials into position by hand where possible. Excessive manual handling should be avoided and cranes and other mechanical lifting devices should be employed when necessary.

Introduction

The aim of this unit is to teach you to design, install and test LPG in caravans,mobile homes, and mobile workplaces.

States or Territories gas Authorities apply different certification schemes when the installation is completed. It is therefore of the utmost importance that you have made the installation in a safe, tradesman–like manner to ensure the safety of the consumer. The principles learnt here may be applied to new or existing vehicles and marine craft. They are also relevant for any appliance replacement or servicing that may be carried out in existing caravans.

A definition of a caravan isfound in (relevant version) (AS/NZS 5601):

‘a structure that is or was designed or adapted to move from one place to another, whether it is towed, transported or self-propelled, and which is intended for human habitation or use as a workplace. This includes camper vans, mobile homes, on-site vans, and commercial food vans. It does not include fabricated transportable homes or demountable classrooms, etc’.

A typical basic installation in a caravan,mobile homes, and mobile workplace would be a cooker and refrigerator which are supplied by one 9 kg gas cylinder. Occasionally a room heater and/or hot water service may also be installed.

The installation you will be doing is for a caravan,mobile homes, or mobile workplace so these training notes will be written about these types of installation.

Before you can plan and install LP gas cylinders in caravans,mobile homes, and mobile workplaces, there are a number of issues that you must know about. These include:

  • the properties of LP gas
  • ignition and combustion principles
  • pressure and flow rates
  • gas safety
  • electrical safety.

Note
There are two main types of LP gas: Propane and Butane. Because of our climatic conditions, we use Propane for fuel gas.
Automotive LP gas is a mixture of Butane and Propane and is not suitable for use with gas appliances.
Butane is also found in disposable gas canisters which can be recognised by the rubber valve in the top of the canister. A needle valve similar to the one used for inflating footballs, etc with a pump is inserted through the rubber valve to obtain gas.
All references to LP gas from this point on refer to Propane.

Properties of LPG

  • LP gas is colourless and heavier than air. It will flow downwards and collect on the ground unless there is ventilation or air movement.
  • A strong pungent odorant (Ethyl mercaptan) is added to assist in the detection of even minor leaks.
  • LP gas is non-toxic, but if inhaled in sufficient volume, asphyxiation may occur.
  • If a given volume containing between 2-9.6% of LP gas in an air-mix is ignited, it will flash and, if in a confined space, it will explode.
  • LP gas is stored under pressure to maintain its liquid state. When the pressure is released, it vaporises and in the process expands to 270 times its liquid volume. 1 litre = 0.270 m3 of gas vapour.
  • The travel of flame in LPG vapours in open air is about five metres/second
  • Ambient temperature increases the vapour pressure of LPG inside containers and also causes the LPG liquid to increase in volume. LPG cylinders and tanks are so designed that they should never be filled with liquid to more than 83% of their total capacity.
  • LP gas will cause deterioration of natural rubber. Therefore only approved jointing compounds, lubricants and synthetic hoses must be used.
  • The ignition temperature of Propane is between 493-5490 C.

The average properties of Commercial LP gas (propane) at 150C
Formula / C3H8
Specific Gravity of liquid (water = 1) / 0.51
Specific Gravity of gas (Air = 1) / 1.53
Boiling Point of liquid (vaporisation) at atmospheric pressure 0C / – 420C
Kilograms per litre liquid / 0.508
Litres per kilogram liquid / 1.97
Cubic metres gas per kilogram liquid (101.325 kPa) / 0.528
Cubic metres gas per litre liquid (101.325 kPa) / 0.268
Flammability Limits (% gas in air)
Lower / 2.4
Upper / 9.6
Latent heat of vaporisation at Boiling Point (m3/kg) / 0.536
Air required for combustion (volume/volume)
Stoichiometric / 23.8
With 40% excess air / 33.3
Heating Values (megaJoules)
mJ/m3(gas at 150C, 101.32bkPa) / 96
mJ/litre (gas at 150C,101.325 kPa) / 0.0955
mJ/litre (liquid at 150C) / 25.6
mJ/kg / 50.01
Vapour Pressure (kiloPascals)
ºC / kPa absolute / kPa gauge
-15 / 295 / 195
0 / 480 / 380
20 / 850 / 750
40 / 1395 / 1295
55 / 1915 / 1815

Ignition and combustion principles

Combustion is a rapid chemical reaction between a fuel and oxygen, which gives off heat. Usually the oxygen comes from the air, which is about 21% oxygen and 78% nitrogen.

Most fuels contain carbon and hydrogen and when combined with elements like oxygen, heat is given off. In gas, carbon and hydrogen usually don’t appear as pure elements. Instead they are combined into chemical compounds called hydrocarbons.

When hydrocarbons are burned, the heat of combustion breaks them down and they begin to react with the oxygen, forming a new group of compounds called aldehydes. These in turn break down and react with the rest of the oxygen producing carbon dioxide and water vapour.

Nitrogen, being an inert gas, passes through the combustion reaction unchanged.

The heated gases, carbon dioxide, nitrogen and water vapour are called the products of combustion or flue gases.

Once the gas or air mix is heated to the required temperature for ignition – between 4930 C and 5490 C for propane – the resultant chemical reaction is generally sufficient to maintain further combustion.

Combustion or burning of gas (or any other fuel) can only occur when three factors are united. They are the fuel, oxygen and ignition. Combining them together forms a combustion triangle.

The combustion triangle

Should one of the factors be omitted, combustion cannot take place.

Gas combustion

Gas combustion is generally described as:

  • complete
  • incomplete.

Complete combustion

Complete combustion is the total breakdown of the fuel into carbon dioxide, nitrogen and water vapour. This is discussed in the previous section.

Complete combustion occurs when the correct volume of oxygen (obtained from the surrounding air) is supplied for each volume of gas to be burnt.

The ratio is 24 parts air to 1 part gas (propane). We call this the ideal fuel/air ratio or stoichiometric ratio.

Note
Stoichiometric ratio means chemical equation of combustion.

Complete combustion ensures:

  • maximum appliance efficiency
  • safe products of combustion produced and released into the atmosphere.

The air to gas ratio to a burner is maintained by ensuring sufficient: