Basic electrical site

Principles of combustion and heating gases

Fire triangle

When fuel or flammable materials are heated, the energy stored inside starts to react with oxygen in the air, giving off heat. This creates a vicious cycle, which causes the fire to spread. To stop the spread of a fire you have to remove one of these elements to break the triangle

Remember- When working with heat producing equipment always use heat proof mats to protect the fabric of the building and also always have a fire extinguisher ready from your PPE kit.

Types of gases used in the plumbing industry

Giant propane explosion

Chart: LPG packs more punch: both propane (red) and butane (blue) contain considerably more energy per cubic meter than natural gas (yellow); in other words, they're more calorific. Butane holds more energy than propane because a molecule of butane has three more atoms than a molecule of propane and three more chemical bonds holding it together. More bonds break when you burn butane, so more energy is released during combustion. Figures in megajoules per cubic meter.

Data from Calor Gas UK.

Gases used in blow torches-

Blowtorches can use different gases depending on the kind of work done. Professional gas torches use acetylene or MAPP gas to mix with oxygen, while smaller, home torches typically use either butane or propane

Various gases are used in plumbing situations:

- Soldering
- Heating water
- Space heating
- Cooking

Air to gas ratios

Natural gas Propane Butane
10:1 24:1 30:1

Natural gas: commonly used in domestic properties for boiler and cooker fuel. Ventilation is required in certain applications. Not hot enough for soldering.

Propane: commonly used for caravan boiler and cooking. Also used if mains gas is unavailable. Ventilation required.

Butane: commonly used in barbecues, due to high calorific value. Too hot for soldering. Ventilation required.

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