Propane bottle gauge.

Hello all,

Does anyone know a method of gauging how much gas is left in the bottle, other than when the torch goes out..

Can you weigh the bottle maybe ?

Thanks,

Brian

The gas bottle should have a metal disk around the neck with the empty weight embossed into it. Weigh the whole thing and you can see how much gas is left.

I think that there is a liquid in the gas bottle (besides the compressed gas) because when mine is "empty" there is still a sloshing sound inside it.
BobH

I've seen these temperature sensitive labels sold but I've no idea whether they work reliably or not.

**LINK**

I imagine that they rely on the liquid in the bottle being at a different temperature to the gas above it - but this might only work if there is gas flowing since there probably needs to be evaporation happening to achieve a cooling effect? You also need to stick them close to the top of the liquid.

May be snake oil but at £3 delivered it might be worth a punt.

HTH

Jon

Because the gas is stored in liquid form, you'd think you can't easily tell how much remains eg by measuring the pressure - until it's too late! Having said that, my Calor "Patio Gas" container has a gauge next to the tap saying "High" and "low". It doesn't have anything to go on other than the pressure of the gas so I don't understand. Never emptied one so I don't know how linear the scale is.

When you use it, you can often see where the liquid level is by the presence of condensation on the outside of the bottle. That requires a certain rate of usage and relative humidity.

The foolproof method must be weighing it as Dennis suggests. Those electronic scales are pretty good and the difference in weight between a full and an empty one is pretty big (13kg), so should be pretty easy to gauge how full it is.

As the liquid gas evaporates it cools down which is obviously how those labels work - and what causes the condensation. That also sounds like an excellent excuse to buy an infrared thermometer which you might claim to have other uses in the home and workshop (SWMBO etc).

Propane gas is bought effectively by weight, hence the Tare Weight for the bottle and the Maximum Weight of a full bottle. If you can hear liquid sloshing about there is "some" left obviously. A full bottle does not slosh. Pressure will vary with temperature which is why a cold bottle stored outside doe not work as well, as the liquid gas cannot evaporate so readily. Self refilling is not recommended (see recent "accident" in Africa news report)

You can buy (or could ) a proper bottle weighing machine. Or just a cheaper one if you don't mind lifting the bottle. This is the only way to measure accurately.

Interestingly, a quick dig around suggests that the Calor gas trac system uses a float rather like a petrol tank gauge. That explains it!

But yes, one of those kitchen or human electronic scales (depending on the cylinder) sounds like the best solution.

You used to be able to get a gauge that fitted between the gas tank and the regulator from caravan or camping stores

Roy

Bet it didn't work though. The gas pressure remains constant until the liquid is gone. And then you have run out. Not much a sensor in the pipe can tell you until it's too late. Possibly why they no longer sell them?

Thanks all the the reply's.

Looks like weight is the way to go, and would guess that 19kg would be the total weight for both bottle and gas when full and not 19kg worth of gas..

As Muzzer says, a gauge is useless to determine how much gas is left until there isn't any left. the only way is to weigh the bottle against the Tare weight stamped on the bottle.

The 19kg is the charged weight and is usually painted on, the Tare weight is stamped somewhere.

I work in refrigeration / air conditioning, and people are often confused that a system is showing a good standing pressure, which they equate to it having a good gas charge, until the compressor starts, and suddenly there's no pressure due to the system having lost most of its bulk gas charge. This is the same if it's a small system holding a couple of kg's of gas or an industrial system holding up to a tonne.

Muzzer I didn't say that it worked

Roy

What you need but a HP one

Edited By JasonB on 08/01/2016 18:02:32

Weighing the bottle is the best way to know how much [liquid] gas is left in the bottle, propane being better in the winter as it will still burn when butane can't, that's one of the the main reasons for using it & the calorific value is not much different between them, the price for smaller bottles is a rip off when you compare it to autogas at filling stations.

Just borrowed the bathroom scales much to the annoyance of some....

Empty weight is 17.5 kg as stamped on the bottle but this it not overly clear.

There is an aluminium disk around the outlet of the bottle which reads 38 12, not sure what this means.

Bottle weight currently is 36.1 kg so based on that I have 18.6kg of propane..

If this is correct then It should last a while me thinks...

yes the 17.5Kg will refer to the bottle weight so you've got lots left. Sloshing indicates some gas left in the liquid state so not empty.

When you replace it try for one of the "lightweight"| bottles which are partially see through - BP gas light is one brand- you can then see the level of liquid remaining .

Regards Ian

Just a guess, 38 lb and 12 oz.

JA