How to check a gas cylinder’s weight: read the tare weight stamped on the carry handle, choose a suitable scale, work out the actual gas, compare it with the nominal quantity and know what to do if the cylinder is short.
When you buy a 12kg gas cylinder, you are paying for the 12kg of gas inside, but nobody can see through a steel cylinder. The most reliable way to check a gas cylinder’s weight is to weigh it and do a simple subtraction.
The figure 12kg or 45kg is the nominal quantity of gas, excluding the cylinder itself. “Full weight” means that the weighed mass minus the tare weight equals the nominal quantity, within the permitted tolerance. At filling plants, cylinders are filled by weight and check-weighed afterwards — see the gas filling process.
The mandatory information for a cylinder — the owner’s name, manufacturing standard, manufacturer, month and year of manufacture, tare weight and working pressure — is stamped on the carry handle together with the serial number.
Formula: actual gas = weighed mass − tare weight marked on the handle.
Illustrative example: a 12kg cylinder weighs 26.4kg and the handle shows a tare weight of 14.3kg, so the actual gas is about 12.1kg — effectively full. If it weighs only 24.8kg, the actual gas is about 10.5kg, which is clearly short.
Every scale has some error, so a small difference on a household scale is not enough to conclude that a cylinder is underfilled; permitted tolerances follow current metrology regulations. Only large differences that recur across several cylinders are worth raising — in that case, reweigh the cylinder on the dealer’s trade scale with both parties present.
The best time to check a gas cylinder’s weight is at the moment you receive it: check that the seal on the valve is intact, ask for it to be weighed on the spot and read the tare weight together. Restaurants that use many cylinders should record the weighing result each time they take delivery. For how to recognise a trustworthy dealer, see how to choose a reliable gas dealer.
The seal shows that the cylinder has not been opened since it left the filling plant. A cylinder without its seal may have been decanted illegally, is more likely to be short of gas and has not been checked as it would be at a plant that meets the required conditions — do not accept it. A cylinder that runs out quickly may also be leaking; see how to check for gas leaks at home before drawing conclusions.
Close the valve and remove the regulator before weighing, so that the hose does not take some of the weight — for how to do this, see how to change a gas cylinder at home.
It is difficult, because you need a floor scale and two people to lift it; it is best to ask the dealer to weigh it on delivery.
Rust, repainting or a valve replacement can make the actual tare weight differ slightly, so weighing at home is mainly for spotting clear differences; in a dispute, reweigh the cylinder on the dealer’s scale.
VietnhatGas manufactures 12kg LPG cylinders and 45kg LPG cylinders with the tare weight and serial number clearly stamped on the carry handle, making filling by weight and checking easy. Send a request on our quotation page.
Written by the VietnhatGas technical and sales team — a batch manufacturer of LPG cylinders. This content is for reference; regulations and standards may change, so please check the current texts.
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