The term “liquefied gas” may seem a contradiction in terms since all things in nature are either a liquid, a solid or a gas.Yet, it is the unique character of LP Gas that makes it such a popular and widely used fuel. LP Gas at normal temperature and pressure is a gas. It changes to a liquid when subjected to modest pressure or cooling. In liquid form the tank pressure is about twice the pressure in a normal truck tire.
The reason LP Gas is liquefied is to make it easy and efficient to transport and store. One unit of liquid has the same energy content as 270 units of gas. If left as a gas the container to hold the fuel would be 270 times larger than what is required as a liquid. In other words, LP Gas has density (compactness) for storage and transportation, yet all the benefits of a clean vaporous fuel when used at the burner tip.
LP Gas usually consists of a mixture of propane and butane for standard heating and cooking purposes. Propane starts vaporising above -45°C, so it is more versatile for general use. Butane starts vaporising above -2°C and requires a propane / butane mixture in cold environments as it will not vaporise as readily as propane.
(Source: World LP Gas Association)
All refillable cylinders available in the UK should have their Tare weight (the weight of the empty cylinder), which can vary slightly, either stamped into the base ring or cowl or on a tag around the valve stem. In the table below we've listed the empty and full weights from the information supplied by several manufacturers. Hopefully this will help you work out how much gas you have left.
| Cylinder Weights | ||
| BP Gas light | ||
| (Butane) | ||
| Nominal Size | Weight of Cylinder | Total weight of full Cylinder |
| 5 kg | 3.7 kg | 8.7 kg |
| 10 kg | 6.7 kg | 16.7 kg |
| Calor | ||
| Nominal Size | Weight of Cylinder | Total weight of full Cylinder |
| 3.9 / 4.5kg | 5kg - 6kg | 9kg - 10.5kg |
| 6 / 7 kg | 9 kg - 10kg | 15kg - 17kg |
| 12 / 13 / 15 kg | 13kg - 20kg | 25kg - 35kg |
| 18 / 19kg | 20kg - 29kg | 30kg - 48kg |
| Calor Patio Gas | ||
| (Propane) | ||
| Nominal Size | Weight of Cylinder | Total weight of full Cylinder |
| 5kg | 7kg | 12kg |
| 13kg | 14kg | 30kg |
| Campingaz | ||
| (Butane) | ||
| Size | Weight of Cylinder | Total weight of full Cylinder |
| 907 | 3.6kg | 6.4kg |
| 904 | 1.5kg | 3.3kg |
| 901 | 800g | 1.2kg |
| FLO GAS | ||
| (Butane) | ||
| Nominal Size | Weight of Cylinder | Total weight of full Cylinder |
| 13kg | 12kg - 13kg | 25kg - 27kg |
