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-   -   Propane gauge (https://www.airforums.com/forums/f287/propane-gauge-24129.html)

nazz300 07-05-2006 09:05 PM

Propane gauge
 
I have to ask a dumb question: I hate not knowing how much propane is left in my tanks. Does anyone use a propane guage on their tanks? If so, do they work? I know I have 2 tanks but it would be nice to know when one is getting empty. Any feedback?

Condoluminum 07-05-2006 09:12 PM

Weigh them...
 
We had little success with "Mood Band" strips that are supposed to show level by temp changes or other gimmicks. I haven't had experience with color-coded pressure guages.

We finally decided to weigh our tanks empty and full on bathroom scale... Now we know that 16# is empty, 37" is full, and we can compute the fullness in between... Takes a little effort to unload them, but process is foolproof once they're disconnected.

Your tank weights may vary, but theory is valid for any size tank...

John McG

bill benton 07-05-2006 09:14 PM

Yes We use a in line gage but it will only tell us when the tank is almost empty. Its one of the ones that goes from green to red. You can get them from Camping world, hd, or Lowe's. I don't remember which one. They were about $20.00 each.

lewster 07-05-2006 10:51 PM

Nazz,

Since LPG (propane) stands for liquified petroleum gas, the key word here is 'liquid'. When the tank is full, it is only at 80% to allow room for the liquid to 'boil off' into a gas form so it can flow to your appliance.

That said, there is no practical way currently to guage the amount of liquid propane remaining in the tank. Some of the gadgets give you an 'idea' of the level. I have seen Weber grills that use a crude scale arrangement that provides a better idea of the level by weight remaining than the guage types.

The best way is to run a 2 tank set-up with an auto change-over regulator. Check it every once-in-a-while and you can see when the tanks have switched so you can remove the empty for a refill.

thecatsandi 07-05-2006 11:24 PM

My tanks in my Classic have a direct read liquid level guage and a electrical hookup for reading inside. THe direct read guage does work well. You can get the tanks with the guage in them from vintage trailer supply for a "reasonable" price.

Torii 07-05-2006 11:58 PM

Quote:

Originally Posted by lewster

The best way is to run a 2 tank set-up with an auto change-over regulator. Check it every once-in-a-while and you can see when the tanks have switched so you can remove the empty for a refill.

I've done this for awhile and I must say it works very well...

Minnie's Mate 07-06-2006 08:11 AM

Quote:

Originally Posted by lewster
Nazz,

The best way is to run a 2 tank set-up with an auto change-over regulator. Check it every once-in-a-while and you can see when the tanks have switched so you can remove the empty for a refill.

This is the set up we have. Our dealer recommended leaving one tank closed. When the open tank runs out and the switch flips over to the closed tank, there will be no gas going to the trailer and we will know that we have to go out and switch tanks and fill the empty one. This set up uses the closed tank as a reserve tank. The only problem is that means that we might run out of gas while pre-cooling the fridge in preparation for a trip and not have a chilled fridge when it's time to load it or run out in the open tank while going down the road and have spoiled food when we arrive at the camp site and have the inconvenience and expense of having to go to the grocery store and replace everything that went bad just as we arrive at the campground or find that the water heater quit working during the night and we have no hot water for a shower in the morning. If we open both tanks during pre-chill and transit times, we defeat the "reserve" tank theory.

I was wondering if there was a reliable tank guage my self for these reasons.

nazz300 07-06-2006 08:49 AM

Thanks Lew, who's better than you?

Although now Minnie Mate's response poses a question:

I'm assuming you leave both tanks open and the regulator closes the reserve tank automatically. When the service tank empties I assume a valve turns or changes over from the service tank to the reserve giving a continuous gas supply without interruption.

Is this correct?

jcanavera 07-06-2006 08:52 AM

While I have a gage on the Classic, I remember about 18 years of camping with pop-ups and my old Hi-Lo that didn't have a gage. How did I keep track of gas? Well much like the previous post I always had a twin tank setup and kept one tank closed. That way I always knew for sure when a tank was exhausted.

The other way I kept track of levels was to occasionally check the tank in use when a heavy use appliance was operating. Either a water heater or the furnace. In most cases when those appliances were operating, moisture in the air would condense on the cold portion of the tank. It always allowed me to visually see that line of liquid which in effect was the level of propane left in the tank. It always worked for me and I never was surprised by running out of gas at an inopportune time.

Jack

lewster 07-06-2006 10:06 AM

Quote:

Originally Posted by nazz300
Thanks Lew, who's better than you?

Although now Minnie Mate's response poses a question:

I'm assuming you leave both tanks open and the regulator closes the reserve tank automatically. When the service tank empties I assume a valve turns or changes over from the service tank to the reserve giving a continuous gas supply without interruption.

Is this correct?

Correct. The operational theory of the auto change regulator is to have both tanks open. The regulator is either on tank#1 or tank#2, never both at the same time. When your primary (#1 tank) is empty, the regulator's indicator will then show red and you have a visual that tells you when the regulator is using the reserve tank. When the change-over occurs, the regulator does not give you 100% gas flow, but provides LP at a reduced rate. You then manually switch the regulator valve over to the reserve tank for 100% flow, and it then becomes the primary and the indicator is again green. You then fill the empty and IT becomes the reserve.

The process begins again when the #2 (now primary) tank is empty and you switch the regulator valve making the #1 (reserve) the new primary. It flip-flops like this as long as you use the propane system.

Also, like Michelle said, a LLG or liquid level guage will give you a good idea of where your liquid propane level is, but I have never seen them used in DOT tanks like the ones we have on the trailers. They are mostly used on the horizontal ASME tanks found in MoHo's.If they are now available for DOT tanks, that may be the way to go, but the upright design of the DOT tank is a limiting factor for the sensor that must be placed inside the tank for the guage to work. The ASME tanks are better suited because they are horizontal, larger in diameter and have up to 5 openings in the tank for such usage.

Michelle, if you have the time, take a shot of your set-up. Very interesting!

Thanks!

myoung 07-06-2006 10:29 AM

Isn't it true that when the propane tanks are in use the liquid at the bottom is cool enough to condense moisture on the side? By observing the moisture you would have an idea how much liquid there is in the tank. A full tank is supposedly 80% liquid leaving enough room for the gas to form at the top of the tank.

jcanavera 07-06-2006 10:46 AM

Quote:

Originally Posted by myoung
Isn't it true that when the propane tanks are in use the liquid at the bottom is cool enough to condense moisture on the side? By observing the moisture you would have an idea how much liquid there is in the tank. A full tank is supposedly 80% liquid leaving enough room for the gas to form at the top of the tank.

Yep, that's what I was saying in post #9. The key is you need to have some high use appliance running at the time to cause the cooling effect as the liquid turns to a gas state. If there isn't enough humidity in the air to cause condensation, you usually can feel the temperature difference between the liquid and gas areas. Obviously if that usage isn't occuring, there will be no condensation or temperature difference.

Jack

Minnie's Mate 07-06-2006 11:00 AM

Quote:

Originally Posted by lewster
Correct. The operational theory of the auto change regulator is to have both tanks open. The regulator is either on tank#1 or tank#2, never both at the same time. When your primary (#1 tank) is empty, the regulator's indicator will then show red and you have a visual that tells you when the regulator is using the reserve tank. When the change-over occurs, the regulator does not give you 100% gas flow, but provides LP at a reduced rate. You then manually switch the regulator valve over to the reserve tank for 100% flow, and it then becomes the primary and the indicator is again green. You then fill the empty and IT becomes the reserve.

My problem is that our tanks are in a tank cover and we don't have visual access unless I open the cover to check. That was the idea behind leaving one tank closed. You would find out by not having gas in the trailer. The other thing is that we do most of the cooking outside so far using a table top gas grill. More than likely I won't run out of gas any time soon, but when we take our next outing we will be on the road for about 10 hours each day of the trip and that will already have about 17 hours of use of the refridgerator on LP by the time we start out. As a back up I will open the second tank so we don't run out of LP en route, but I won't know for sure until I open the cover and visually check the switchover valve as to when the first tank runs out.

Something a little more accurate would be a whole lot more convenient, but if it isn't available it isn't available.

lewster 07-07-2006 01:45 AM

The Monaco Dynasty MoHo that I used to full time in had an LP indicator on the control panel. It was tied into the ASME tank's liquid level guage and sent a signal to the monitor panel that also had the waste tanks ,fresh water and battery levels. DOT tanks like we use are not set up for this type of monitoring.....yet.

ZoomZoom 07-07-2006 06:37 AM

Propane Level
 
The easiest and cheapest way to determine how much liquid is left in a tank is to pour luke warm water down the side of the tank, you will see a visable level of condensation form at the point of liquid level in the tank, and this method cost nothing.

Zoom

Minnie's Mate 07-07-2006 09:48 AM

Quote:

Originally Posted by ZoomZoom
The easiest and cheapest way to determine how much liquid is left in a tank is to pour luke warm water down the side of the tank, you will see a visable level of condensation form at the point of liquid level in the tank, and this method cost nothing.

Zoom

Do you need to have a heavy using gas appliance operating at the time?

jcanavera 07-07-2006 11:47 AM

Quote:

Originally Posted by Minnie's Mate
Do you need to have a heavy using gas appliance operating at the time?

It probably helps a lot. If there is relatively little gas usage occuring, and your outside temperature is fairly equivalent to the propane then that method may not give you the results you are looking for.

Sometimes you can also see that level when on a damp morning, you have a rapid increase in outdoor temperatures. In some cases the liquid propane will be slower to warm and therefore the liquid level forms condensation around the tank.

Jack

Minnie's Mate 07-07-2006 12:33 PM

Quote:

Originally Posted by jcanavera
It probably helps a lot. If there is relatively little gas usage occuring, and your outside temperature is fairly equivalent to the propane then that method may not give you the results you are looking for.

Sometimes you can also see that level when on a damp morning, you have a rapid increase in outdoor temperatures. In some cases the liquid propane will be slower to warm and therefore the liquid level forms condensation around the tank.

Jack

Is that why you use luke warm water?

Bob Thompson 07-07-2006 12:39 PM

I saw something that may point towards the future on TV over the weekend. They were doing a piece on "CLEAR" propane tanks for outdoor grills. They were clear enough to see the level inside. Who knows, maybe it will make it to RV's. I could see a possibility for polycarbonate tanks. Anyone know what the pressure is inside a full propane tank?

jcanavera 07-07-2006 01:22 PM

Quote:

Originally Posted by Minnie's Mate
Is that why you use luke warm water?

Yes. What you are trying to do is reproduce what happens when a cold glass sits in a warm moist environment. Again dependent upon outside air temps and the temps of the propane in the tank, this process may or may not work. That's why with a heavy use of propane going on, your success rate will be much better since the propane changing from a liquid to a gas state produces a cooling effect in the tank.

Jack


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