NSW Gasfitting key terms

Work on gas installations or appliances that requires a licensed gasfitter, covering installation, alteration, disconnection, servicing and commissioning of consumer gas piping and connected appliances.

A licensed gasfitter holding the supervisor certificate that authorises them to supervise and certify the gasfitting work of others and to sign compliance documentation for completed work.

The business-level authorisation allowing a person or company to contract for gasfitting work, provided the work is supervised and certified by a nominated qualified supervisor.

A certificate issued by the licensed gasfitter on completion of work, declaring that the installation complies with the relevant standard and regulation and notifying the work to the authority.

The Australian Standard governing the design, installation and commissioning of natural gas and LP gas consumer piping and appliances, forming the technical basis for compliance in New South Wales.

All gas piping, fittings, valves and appliances downstream of the gas supply point that serve the consumer's premises, and for which the gasfitter is responsible.

The point where gas leaves the supply meter or regulator and enters the consumer's piping, marking the boundary between the distributor's assets and the consumer installation.

A device that reduces the pressure of gas from the distribution main to the pressure required at the consumer's meter, maintaining a steady outlet pressure as demand varies.

The force exerted by gas on the walls of its container, measured in kilopascals and critical to correct appliance operation, combustion performance and safe piping design.

The pressure at which an appliance or section of piping is designed to run under normal conditions, verified at commissioning and checked against the appliance data plate.

The pressure applied during a strength or leak test of piping, typically higher than operating pressure, held for a specified period to prove the installation is sound.

A documented procedure in which piping is charged with air or inert gas and monitored with a gauge to confirm it holds pressure without leakage before gas is introduced.

A check for gas escape using an approved detection method such as soap solution or an electronic detector, applied to joints and connections after gas is introduced.

The controlled displacement of air or inert gas from piping or an appliance with the fuel gas, or of gas with air, so that combustible mixtures are not created or left behind.

The final stage of installation in which the appliance is started, adjusted and tested for correct gas pressure, combustion and safety performance, and the results are recorded.

The chemical reaction in which fuel gas combines with oxygen, releasing heat and producing carbon dioxide, water vapour and, when incomplete, carbon monoxide.

The ideal mixture in which exactly enough oxygen is supplied to burn all the fuel, producing maximum heat release with no surplus fuel or oxygen remaining.

The proportion of air supplied above the theoretical requirement for complete combustion, needed in practice to ensure all fuel burns but kept low to limit heat loss.

The ratio of air to fuel entering a burner, which determines flame stability, combustion efficiency and the level of carbon monoxide produced.

A colourless, odourless and highly toxic gas produced by incomplete combustion, which must be kept to minimal levels and detected by combustion analysis.

Burning that leaves unburnt fuel or produces carbon monoxide, caused by insufficient oxygen, poor mixing, blocked flues or over-gassing of the burner.

Measurement of flue gas oxygen, carbon dioxide, carbon monoxide and temperature with an electronic analyser to assess burner efficiency and confirm safe, complete combustion.

A duct or passage that carries products of combustion from an appliance to the outside air, designed to ensure safe dispersal and prevent combustion gases entering the building.

The outlet end of a flue, positioned to clear building openings, air intakes and combustible surfaces by the specified distances so combustion products disperse safely.

The escape of combustion products from an appliance into the room rather than up the flue, indicating a fault such as blockage, downdraught or inadequate draught.

A permanent opening, such as a wall vent or ceiling register, sized to supply combustion air and dilute contaminants for an appliance in accordance with the standard.

A control system that senses the presence of a flame and shuts off the gas supply if ignition fails or the flame is extinguished, preventing unburnt gas release.

A sensing device that generates a small voltage when heated by a flame, holding a safety valve open and closing it when the flame is lost.

An unintended escape of fuel gas from piping, fittings or an appliance, which must be isolated, made safe and repaired before the installation is returned to service.

A valve installed on consumer piping or at an appliance inlet that allows the gas supply to be shut off for servicing, emergency control or disconnection.

The use of electronic instruments or odour to identify the presence of fuel gas or carbon monoxide in air, guiding evacuation and isolation decisions in an emergency.

A fuel gas supplied through mains networks, composed mainly of methane, which is lighter than air and has a narrow flammable range and high ignition temperature.

Liquefied petroleum gas, supplied as propane or butane in cylinders, which is heavier than air, accumulates in low areas and has a wider flammable range than natural gas.

The arrangement of LP gas cylinders, regulators, pigtails and changeover valves at a property, sited and secured to meet separation and ventilation requirements.

A capped or plugged tapping on piping or an appliance regulator where a manometer or gauge is connected to measure operating or test pressure.

An instrument, often a water-filled U-tube or digital gauge, used to measure low gas pressures and confirm readings at test points during commissioning and testing.

The systematic process of diagnosing appliance or installation faults by gathering symptoms, testing pressures, flame and electrical controls, and confirming the repair.

Obligations requiring licensed, safe and honest work, clear documentation and proper notification, so consumers receive compliant installations and recourse for defective work.