Propane bottle gauge.

[Brian AbbottParticipant @brianabbott67793]

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

[Brian AbbottParticipant @brianabbott67793]

[Dennis RaynerParticipant @dennisrayner52782]

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.

[Speedy Builder5Participant @speedybuilder5]

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

[Jon GibbsParticipant @jongibbs59756]

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

[MuzzerParticipant @muzzer]

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.

[MuzzerParticipant @muzzer]

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).

[KWILParticipant @kwil]

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)

[Gordon WParticipant @gordonw]

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.

[MuzzerParticipant @muzzer]

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.

[roy entwistleParticipant @royentwistle24699]

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

Roy

[MuzzerParticipant @muzzer]

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?

[Brian AbbottParticipant @brianabbott67793]

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..

[Andy HoldawayParticipant @andyholdaway]

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.

[roy entwistleParticipant @royentwistle24699]

Muzzer I didn't say that it worked

Roy

[jason udallParticipant @jasonudall57142]

Those liquid crystal gauges work by straddling the level of liquid gas.
You then pour boiling or near boiling water on the scale

Thus the temperature of the scale below the liquid level doesn’t rise as much as the scale above …the level is indicated but the transition of cold/hot scale.

Pretty fool proof but messy

[JasonBModerator @jasonb]

What you need but a HP one

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

[the artfull-codgerParticipant @theartfull-codger]

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.

[Brian AbbottParticipant @brianabbott67793]

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…

[Ian WelfordParticipant @ianwelford58739]

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

[JAParticipant @ja]

Just a guess, 38 lb and 12 oz.

JA

[EmgeeParticipant @emgee]

JA is correct, weight stamped on the ally disc is in lbs and ozs.

I have a record of the 13kg gas size weighing 27.5kg when full.

Emgee

[JohnFParticipant @johnf59703]

Kiwi's have the best idea you take your bottle to the filling depot, place on the scale and dial in the tare weight shown on the bottle add gas to the full level/weight and pay for the amount added. You can top up anytime! No guessing how long before you run out or changing your bottle with gas still in thus wasting it.😊

[Steven VineParticipant @stevenvine79904]

I use the small Primus 2000 size bottles a lot, and keep 2 of them. When one runs out I start using the full one and get the empty one filled up in the meantime. I weigh these small bottles on the kitchen scales and it is a good indicator of how much is left. Having a spare means I don't get caught out.

I have a larger 3.9kg bottle that I do not use much yet. I'll get a spare one when I start boiler making in earnest.

Steve

[John HaineParticipant @johnhaine32865]

On our first camping trip in Scotland I was worried that our Gaz cylinder would run out. Since it had tare and full weights stamped on it I thought it would be a good idea to buy a little spring balance to check it. So we went into a big hardware store and they didn't have anything but suggested we tried the fishing tackle shop. There I found a neat little Spring balance that would weigh up to 28 lbs, just the job. Stamped on it there was a brand name…"Gazweigh"!

Later on I developed an ultrasonic handheld gadget for a client, which had a piezo transducer you pressed against the side of the bottle. Based on a standard industrial level gauge the idea was if you were below the gas liquid level the ultrasound would pass through the fluid and bounce back from the far side of the cylinder with a significant delay. It seemed to work but we found that with many gas bottles it gave false readings because the sound rattled around the metal of the bottle and gave similar delays even if you were above the gas level. I discussed this with a metallurgist who wasn't surprised, he said that the average gas bottle was a "metallurgical dog's dinner". Shame really, it would have been a nice product for people depending on bottled gas. At one point I visited a gas stockist to try it out on a range of "empty" bottles, he told me he was able to keep his house warm and cook with what was left in the empties!

[Author]

Posts