How to check how much gas is left
Wrap a wet cloth around the cylinder for about a minute, then feel it. The part still holding liquid gas stays cool and the cloth dries more slowly there, so the line between wet and dry marks the fuel level. Weighing and subtracting the tare weight gives an exact figure.
There is no gauge on a domestic LPG cylinder, but there are two reliable ways to know where you stand.
The wet cloth method
Wrap a wet cloth around the cylinder body, or pour water down its side, and wait about a minute.
The portion of the cylinder still holding liquid gas stays cooler, because liquid LPG absorbs heat as it vaporises. That cooler section keeps the cloth damp for longer while the empty upper section dries first.
The line between wet and dry is roughly the fuel level. Run your hand down the side and you will feel the temperature change at the same point.
The weighing method
This one is exact.
- Find the tare weight stamped on the collar — the empty weight of the cylinder.
- Put the cylinder on a scale and note the gross weight.
- Gross weight minus tare weight is the gas remaining.
A cylinder stamped 15.5 kg tare that now weighs 21.4 kg holds 5.9 kg of gas — about half of an 11.8 kg fill.
Which method should you use?
The cloth method for a quick check with nothing to hand. The scale for an exact figure, and for checking you received a full fill in the first place.
Why does the cold patch appear at all?
Liquid LPG takes heat from the cylinder wall as it turns to vapour. The steel above the liquid line has nothing drawing heat from it, so it sits at room temperature while the wall below runs cooler.
That is also why a cylinder feels cold and can frost slightly during heavy use.
Can you tell by shaking it?
Roughly, and unreliably. You will hear liquid moving, but not how much. Use the cloth or the scale.
Common questions
How can I tell how much gas is left in my cylinder?
Wrap a wet cloth around it for a minute. The part still holding liquid gas stays cool and dries more slowly, so the line between wet and dry marks the level. Weighing it and subtracting the tare weight is exact.
Why does the bottom of my cylinder feel cold?
Liquid LPG absorbs heat from the cylinder wall as it vaporises, so the steel below the liquid line runs cooler than the empty section above it. Heavy use can even frost the surface.
Is there a gauge for a gas cylinder?
Domestic cylinders have no built-in gauge. The wet cloth method gives a quick reading and weighing against the stamped tare weight gives an exact one.
Sargodha Gas has supplied LPG cylinders in Sargodha since 2005. Contact us