ie-rgii-non-domestic-gas-safety key terms

The body of Irish law, principally the Energy (Miscellaneous Provisions) Act 1995 and related regulations, that requires gas works to be carried out safely and only by registered competent persons.

A person registered with the Regulatory Body for Gas Installers in Ireland (RGII) to carry out specified categories of domestic and non-domestic gas work lawfully.

A signed statement by the installer confirming that the gas installation or appliance work complies with the relevant standards and regulations, issued to the customer and retained in records.

Commercial, industrial or public buildings where gas is used for purposes other than a private dwelling, typically involving larger loads, complex pipework and higher-risk appliances.

A predominantly methane fuel supplied through distribution networks, with a relative density below air and a calorific value typically around 38 to 40 MJ per cubic metre.

A mixture of propane and butane stored as a liquid under pressure, which vaporises for combustion and is denser than air, so leaks tend to accumulate at low level.

A measure of the interchangeability of gases, calculated from calorific value divided by the square root of relative density, used to confirm an appliance suits the gas supplied.

The lower and upper concentrations of gas in air within which ignition can occur; methane has roughly 5 percent LFL and 15 percent UFL, and outside these limits combustion cannot be sustained.

Complete combustion in which exactly the theoretical quantity of air is supplied to burn all the fuel, producing carbon dioxide and water vapour with no excess oxygen.

Air supplied beyond the theoretical requirement, expressed as a percentage, which ensures complete combustion but reduces efficiency by carrying heat away in the flue.

A colourless, odourless, toxic gas produced by incomplete combustion, which binds to haemoglobin and can cause death; its presence signals unsafe combustion or flueing.

The measurement and interpretation of flue gas oxygen, carbon dioxide, carbon monoxide and temperature to judge combustion quality, efficiency and safety of an appliance.

An instrument with electrochemical or infrared cells that samples flue gases to measure oxygen, carbon monoxide, carbon dioxide and temperature and calculates efficiency ratios.

The percentage of carbon dioxide in flue gases, used with oxygen readings to indicate whether an appliance is receiving the correct amount of combustion air.

A check performed on open-flued appliances to confirm combustion products are drawn into the flue rather than escaping into the room, commonly using a smoke match or detector.

A verification that an open flue has adequate draught and no blockage, performed before and after appliance servicing by observing smoke or flame behaviour at the terminal.

The negative pressure created within a flue by buoyant hot gases, which must be sufficient to remove combustion products safely under all operating conditions.

A gas appliance designed to draw combustion air from the room and discharge flue products to outside, requiring a verified flue and adequate room ventilation.

An appliance that takes combustion air directly from outside via a balanced flue and returns products outdoors, so it does not consume room air.

A concentric or twin-duct terminal arrangement supplying combustion air to and removing products from a room-sealed appliance, balanced against wind effects.

Purpose-provided permanent openings or mechanical supply delivering the air volume required for safe combustion and dilution of products in non-domestic plant rooms.

Selection of pipe diameters so that gas pressure at each appliance remains within the manufacturer's tolerance at maximum demand, accounting for length, fittings and load.

The loss of gas pressure along a pipe run caused by friction in pipe and fittings, which must be limited so appliances receive their rated inlet pressure.

The pressure at which gas is delivered to an appliance, which must match the manufacturer's stated value for correct combustion and heat input.

The volume or energy of gas consumed by an appliance per unit time, measured at the meter to verify correct input and combustion performance.

A pressure test of the gas installation using air, nitrogen or gas to confirm there are no leaks, with duration and permissible drop set by installation volume and standard.

A check confirming that a meter or valve does not pass gas when closed, performed with a gauge or flame observation before work and after reinstatement.

The controlled displacement of air from a new or reopened gas installation with gas, or of gas with air before decommissioning, to avoid a flammable mixture.

Documentation capturing test pressures, gas rates, combustion readings and appliance settings recorded when an installation is first placed into service.

The valve, usually at the meter or service entry, that isolates the gas supply to the premises and is used in an emergency or for safe isolation of work.

The documented sequence of actions on detecting a gas leak or carbon monoxide alarm: isolate, ventilate, avoid ignition sources, evacuate and contact the emergency service.

Fixed sensors, often in plant rooms or commercial kitchens, that detect flammable gas or carbon monoxide and trigger alarms, isolation or ventilation at set thresholds.

The policies, responsibilities and records a non-domestic gas user maintains to control gas risks, including maintenance, inspection and emergency arrangements.

The pack given to the client on completion, including declarations, commissioning data, operating instructions, warning notices and maintenance recommendations.

A formal label or notice attached to an appliance or installation found unsafe or at risk, describing the defect and the action taken, such as isolation.

A gas system serving process plant, boilers or large burners, typically with high pressures, dedicated gas trains and more complex control and safety interlocks.