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How is LPG weighed?

27 Mar, 2023 | Business LPG Blogs, Residential LPG Blogs

In this article:

A quick look at how LPG is stored and therefore weighed as a liquid but used as a gas
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How much does your LPG cylinder weigh?

When Liquefied Petroleum Gas (LPG) is used in the home, the gas is typically measured in kilograms. LPG gas in gas bottles is weighed and the price is based on the weight of the gas (e.g. 45kg) – let’s explore some more about LPG gas cylinder weight.


Storing LPG in cylinders

Storing LPG in cylinders allows it to be transported in a smaller physical volume than would be required if the gas was distributed in its natural state. Gas cylinders have internal pressures that are higher than atmospheric pressure. LPG must have a boiling point below 20 degrees Celsius in order to be considered a gas. Elgas has the gas cylinder and tank sizes you’re looking for.

Gas Cylinder Weight

Gas cylinder weight is the empty gas cylinder weight (tare weight of the gas bottle) plus the net weight of the gas cylinder contents. The net gas cylinder weight is the reference weight. For example, a 45kg gas bottle has 45kg of net content weight. The total weight of gas in a cylinder can be determined if you know both the weight of an empty LPG gas cylinder and the weight of the cylinder when filled with gas. The difference between the two measurements is the weight of LPG in the cylinder. LPG can also be measured in tonnes and litres of LPG.


Weight of a filled gas cylinder

Full gas cylinder weight is the combination of the empty gas cylinder weight (tare weight) and the net weight of the gas contents. Together they comprise the full weight of a filled gas bottle/cylinder. Additional weight includes the regulator and other fittings. The weight of a filled gas cylinder with 14.2kg contents, for example, is approximately 29.5 kg LPG gas cylinder weight.


Weight of an empty gas cylinder

The empty gas cylinder weight is called the tare weight. The empty gas cylinder weight is stamped into the neck ring or painted on the cylinder. Tare weight is sometimes abbreviated to T.W. The tare weight of gas bottles can vary slightly as there are different gas bottle manufacturers. In other words, empty 9kg or 45kg gas cylinders may fall within a range.

The empty LPG gas cylinder weight variances can be due to differences in cylinder dimensions, thicknesses of steel, and other manufacturing differences, and not the cylinder capacity.

Domestic Gas Cylinder Weights

The full gas cylinder (propane bottle) weight equals the cylinder weight plus the weight of contents. A 9kg BBQ gas bottle, for example, can weigh around 16.3kg -19kg when full. The weight variation is in the empty 9kg gas bottle weight, as 9kg refers to the weight of the contents only.

Gas volume can also be calculated in litres with some basic mathematics.

  • For LPG (propane) 1kg = 1.96L.  Therefore, 14.2kg = 27.832L
  • For LPG (butane) 1kg = 1.724L.  Therefore, 14.2kg = 24.48L
  • For a 75:25 butane/propane mix, 1kg = 1.783L.

Unlike water, 1kg of LPG doesn’t equal 1L of LPG. This is because the density of LPG is less than the density of water. In Australia, where LPG is propane, 1kg of LPG has a volume of 1.96L.
Conversely, 1L of LPG weighs 0.51kg.

Gas Bottle Sizes available

LPG gas bottles for residential and small business use are available in 45kg, 90kg and 210kg sizes. There are also smaller gas bottles used for BBQs, camp stoves, mobile outdoor lighting and other applications. These 9kg and 4kg portable gas bottles are available from thousands of SWAP’n’GO centres all around Australia.

Domestic LPG cylinders can be delivered full and ready to go. These cylinders are the alternative to natural gas and are a common sight with the Elgas delivery service. Larger gas bottles are delivered and placed in position using a forklift. For industrial use, LPG is delivered to on-site LPG tanks.

Checking gas bottle levels

There are several methods of checking how much LP gas you have remaining in your cylinder. For small 4kg and 9kg gas cylinder sizes, it can be as easy as shaking the cylinder. You will be able to hear the contents and with time become a pretty good gauge of how much LPG is in there.

Another simple way of checking that’s useful for 45kg, 90kg and 210kg bottles is the hot water test. With this method, you pour hot water (not boiling) down one side of the cylinder. Then rub your hand down the cylinder. Where the sensation changes from warmer to colder is the level of gas left in the cylinder.

Domestic Gas Cylinder Weights Using a Scale

A 9kg gas bottle weighs approximately 16.3–19.0 kg when full. The full cylinder weight is also called the gross weight. The cylinder weights, empty or full, including the weight of gas in the cylinder, can be ascertained by using a weigh scale.

  • Weigh your empty gas bottle, or refer to the bottle weight on the neck ring.
  • Fill the bottle with LPG and place it back on the scale.
  • The difference between the two measurements is the weight of gas contents in the bottle.
Cooking gas cylinder weight

The empty gas cylinder weight is called the tare weight. The weight of the gas cylinder contents is called the net weight, such as 9kg, 45kg or 90kg. This is the amount of gas you are purchasing. A combination of the two weights is the total weight of a gas cylinder filled with LPG.

LPG gas cylinders are used for cooking, endless hot water capacity, heaters and many other applications. For more information about LPG for home, LPG for business, or SWAP’n’GO gas bottles, contact the professionals at Elgas Australia for information. We are the number one choice for LPG in Sydney, LPG in Melbourne, and LPG gas cylinders in all other Australian regions. Wherever you are, Elgas welcomes you to the freedom of choice that only LPG can provide.

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