How To Check Amount Of Gas In Propane Bottle.

[KEI8MAS]

THIS is my first post on here. be checking out this site for month,s .
if you take hot water and pour on the tank a ring will form on the tank were the level of gas is in the bottle ; being that propane is a cold gas .

[Rocky D]

Welcome to the forum, this is a wealth of information for all things welding...glad to have you aboard. There is no such thing as a dumb question, so ask anything...we also have some fun, too.
You can feel the level by shaking the tank, if you can pick it up. I've never seen a ring on a tank in the rain, tho.

[Bob Post]

you can also check by weight.

[txfireguy2003]

THIS is my first post on here. be checking out this site for month,s .
if you take hot water and pour on the tank a ring will form on the tank were the level of gas is in the bottle ; being that propane is a cold gas .

Might work if the gas was escaping the tank at a high rate, thereby cooling the contents of the tank. But I don't think there would be enough of a temp gradient for it to show up if the valves were closed, or if the tank was only losing gas at a slow (normal) rate, I might have to try it out though. I do know that while in fire training, we had to extinguish an LPG fire where there was actually liquid propane (that's the white cloud you see) blowing out of the tank valve. To do this, you keep the tank cool by spraying it with LOTS of water and advance unsing the water as a shield from the flames until you can reach in and stop the leak if that is possible, in this case by simply shutting the valve off. We never saw any condesation rings on that tank and it was losing pressure REALLY fast, and the water coming from a fire pump is pretty dang hot.

[Ohio Mike]

I usually just pick up the tank and shake it. However in my garage very often I can tell the level by the condensation on the side of the tank. In fact I can tell when I’ve over drawing the tank as that damp condensation ring turns to frost. :D

I’ve never thought twice about it since I’ve seen it on tanks since I was a kid. Even works on diesel and gas tanks on many days here in Ohio. In the morning the tanks are still cold and the sun evaporates the morning dew which will condense on the side of the metal tanks since the liquid inside is much colder. Unfortunately the same thing happens to all my tools :mad:

[Monte55]

Propane............cold gas................no! It is the temp of its enviroment
if not being used. It only starts to cool as the liquid evaporates to a gas
and whether you will see a moisture ring on the tank depends on relative
humidity, dew point, temp, etc.

Freon in a drum is the same. I can have a 30lb drum in my van in the summer and it can be a 120 degrees. As soon as I let refrigerant out as a gas, the temp and pressure start to drop. How cold it gets depends how fast the rate is.

If I turn the drum upside down and release refrigerant as a liquid, the drum itself barely cools down but the liquid changing to a gas at the outlet valve gets very cold because the evaporation is outside.

It's like when you sweat and a breeze hits you. As your sweat evaporates,
the vapor is removing heat from your body.

[Broccoli1]

Number 1 tank runs out-

Set Beer down

Remove from Grill

Put #2 Tank on Grill

Pick up beer

Continue cooking
:D

[Some Creep]

Neighbor once told me you could test for tank level by using a stud finder along the outside. I've never tried it (or even NEEDED to try it). I do the shake test myself. If it's light and I need to do some SERIOUS cooking, the shake test tells me all I need to know.

Anyone else heard of the stud finder method? Did he tell me an urban legend or is he retarded?

[hankj]

KEI8MAS,

Welcome aboard.

As usualll, Ed's advice is to the point with the expected houmorous slant!

If you want to know how much liquid is left, weigh the tank, subtract the tare weight, and divide that by 4.25. The result is liquid in gallons. To find out how many cubic feet of gas that will make, multiply the gallonage by 36.5. That's how much "gas" is left.

I've never seen the "ring-around-the-rosie" unless I was running the turkey fryer or the weed burner. Does "latent heat of evaporation" sound familiar?

Hank

[eddie]

I saw a tip yesterday (some DIY show) where you pour hot water over the bottle...propane is cold and you can see the condensation on the bottle giving you the unused level.

[Conrad_Turbo]

Propane............cold gas................no! It is the temp of its enviroment
if not being used. It only starts to cool as the liquid evaporates to a gas
and whether you will see a moisture ring on the tank depends on relative
humidity, dew point, temp, etc.

Freon in a drum is the same. I can have a 30lb drum in my van in the summer and it can be a 120 degrees. As soon as I let refrigerant out as a gas, the temp and pressure start to drop. How cold it gets depends how fast the rate is.

If I turn the drum upside down and release refrigerant as a liquid, the drum itself barely cools down but the liquid changing to a gas at the outlet valve gets very cold because the evaporation is outside.

It's like when you sweat and a breeze hits you. As your sweat evaporates,
the vapor is removing heat from your body.

Not necessarily to do with evaporation, when a high pressure liquid/gas is released into a lower pressure environment the temperature drops. Likewise when the liquid/gas is put into the tank the pressure goes up along with the temperature. An air compressor is the perfect example of this.

[professur]

I've always just whacked it with a stick and listened to the tone. Never failed me yet.

[slimpickens]

Most of you refilled bottles from home depot ect come with a nifty little checker on the plastic cover that you pour water on but ive seen the "gauges" for sale a hardware stores that i think were magnetic and stick on the side of the tank. that give a good approximation of the level of fuel gas left. I prefer to shake it or hook up my old cutting gauge to check my pressure. The weight of the shaken bottle is difinately different when empty. Oh yeah i got one of those one handed valves and a easy change platform on my new grill so i dont have to even set down the beer anymore.

[tailshaft56]

The stick ons work good but I wouldn't invest in one if plan on swapping tanks. It's best to have two tanks as you don't want to run out of gas. You don't want to fill or exchange a tank unless it's completely empty and it's a PIA to run and exchange the tank in the middle of cooking your food.

[Monte55]

Not necessarily to do with evaporation, when a high pressure liquid/gas is released into a lower pressure environment the temperature drops. Likewise when the liquid/gas is put into the tank the pressure goes up along with the temperature. An air compressor is the perfect example of this.

It has everything to do with evaporation. You refer to it as liquid/gas. Well,
which is it? You say an air compressor is a perfect example. Of what? If you release high pressure from your air tank, it's not cold air although it's entering a lower pressure area. Explain that. If that was the case, why do many
users of air compressors add extra line of air hose prior to reaching a water separator etc? That is to let the air/gas cool so the moisture will condense back to a liquid. Why do we do that if the air is already cooled by your theory when it leaves the tank.
If I take a drum of freon which is high pressure compared to atmosphere at 14.7 psi at sea level and open the valve and direct the vapor at your hand, it is not cold. It feels like a blast of air. The temp inside the drum will drop
where the liquid is evaporating to a gas. Now if I turn the drum upside and blast your hand with liquid freon, as it turns to a vapor through evaporation
(btw....this is what evaporation means) it can instantly freeze your flesh.
Evaporation is a product of temperature/pressure relationship.
Water boils(changes from a liquid to a gas) at 212 degrees at seal level on a standard day. If I apply more pressure to the water, I can raise its boiling point as is done on cooling ststems for cars etc. If I apply enough pressure,
the water will not boil no matter how hot you get it.
Now lets go the other way. If I reduce the pressure on the water enough, I can get water to boil at 30 degrees below zero. Remember.....it's always pressure/temperature relationship.

[treborly]

...my propane tank isnt cold.. and if it was, wouldn't the entire tank be cold?

[Roger]

I can take a full HP air tank and open valve quickly reducing tank pressure. Ice will form on outside of tank. This isn't a good bocause water will condense on inside of tank starting pin hole rust. If you do this on larger low pressure volume tank the flow will stop from ice plug in valve then start again when ice plug melts.

When you do this with CO2 gas a vapor forms above liquid CO2 gas in tank and is blown out the valve. This vapor is mixture of CO2 gas and CO2 particulant forming a CO2 fog. In refrigeration this CO2 fog is called latent heat. This CO2 fog absorbs all the heat it can from any thing it touches so it can evaporate to a gas.

CO2 fire extinguisher has siphon tube in CO2 cylinder and shoots liquid CO2 out of small orifice into cone so there is maximum liquid CO2 vapor and even CO2 snow in cone to cool fire and smother fire with CO2 gas as vapor/snow evaporates changing to gas.

[Hornet]

Monte55 how do you explain carb icing on your old style automobile,when the ambient air temperature is above 50F.How do you explain A/C systems.If high pressure air doesn't lose temp when it's converted to low pressure air,what explains carb icing/air conditioning systems etc.
Propane boils at -44F,i want to see that cube of water boil at -30F even if it's in a vacumn,molucules (sp?) have to have the abilitly to move before they can boil
Another tidbit,propane quits flowing at roughly -44,won't convert to a gas at temps below it's boiling point,found that out the hard way in northern Alberta when i was a kid and the outside temp dropped to close -50F,and the camp furnaces quit
Freeze the bottle in your deep freeze for an hor or 2,then fling it outside in the sunlight,the condensation ring will tell you how much is left in the bottle

[Stick-man]

30428

Has anyone ever tried one of these? I wondered if they are accurate.

[Hotfoot]

30428

Has anyone ever tried one of these? I wondered if they are accurate.

Yup. I've been using one for about two years, and its pretty accurate. Like the gas gauge on a few cars I've had, once it starts diving, it goes faster, but it gives me planty of warning, so I don't run out n the middle of my steaks.

I have a scale gizmo that mounts under a tank that you calibrate to an empty tank, but I've never bothered to use it...I pretty much can tell by picking my Weed Burner tank up as I move it about.:)

[hankj]

Yo, Pilgrims. Dis bee's a two-year ole thread! Looka da lil' nummers onna top left.

Hank