Propane Tank Questions

[JD5210]

I have an underground 500 gallon propane tank. I was wondering how long they last?

I live in the western part of VA. It is close to the house and the ground around it is raised, so I would think it does not get to wet. I did a search and found the soil type is silt loam or silty clay loam, and averages 22 to 32 percent clay and 2 to 6 percent sand.

Another question how often does the anode bag need to be replaced?

Thanks in advance for any help.

 

[Larry Caldwell]

I would think soil pH is more important. Your local suppliers would know about your area. From 3000 miles away, I wouldn't even guess.

 

[kenmac]

the soil in that area is most likely has been attacking that steel tank for a long time.
One would think it had some sort of cathodic protection, such as anodes, etc,. But who knows.

JMO,, I wouldn't want one that was buried at all .

 

[ovrszd]

I struggle with the buried tank issue also. I can't think of any reason to bury one beyond just not wanting to look at it. I understand that to an extent. But then we start talking about long term and I've never heard of a solution to analyzing the condition of the tank. Until it fails. That part bothers me enough that I have no problems with looking out my shop window and seeing a propane tank.

 

[m1garand762]

My parents tank has been buried for over 30 years. As of now it’s not leaking or at least not enough to be detectable heavy clay soils

 

[ovrszd]

My parents tank has been buried for over 30 years. As of now it’s not leaking or at least not enough to be detectable heavy clay soils

My above ground tank is a '51 model. I have no evidence of how long it would have lasted buried.

 

[Cycledude]

This is the first time I ever heard of propane tanks being buried !
As far as I know there aren’t any buried here in Wisconsin.

 

[3Ts]

I have a 1000 gal buried tank. The propane supplier is supposed to check the cathodes with some sort of meter every couple of years.

 

[i7win7]

States with soft sandy soil, in a hurricane zone. the tanks can pop out of the ground. If you have a buried tank and expect a hurricane land fall, you want to make sure tank is filled.

 

[bnold]

1,000 buried here as well.

 

[Ken45101]

I struggle with the buried tank issue also. I can't think of any reason to bury one beyond just not wanting to look at it. I understand that to an extent. But then we start talking about long term and I've never heard of a solution to analyzing the condition of the tank. Until it fails. That part bothers me enough that I have no problems with looking out my shop window and seeing a propane tank.

Okay, I can give you one reason: fire protection. If I lived in an area with wildfires, I would much prefer the tank below ground and protected from ambient heat and fire.

Also, possibly cold protection. At very cold temperatures, propane does not convert to gas. One wouldn't want their heating supply to fail on a -20 or -30 F night. Underground would keep it warmer in most Lower 49 geographies.

So there are two reasons although I agree aesthetics are often a primary rational.

 

[grsthegreat]

I also have a 1000 gal buried tank. It is only 4 years old….will outlive me. So no worries.

 

[gasman1075]

We have been burying propane tanks where possible for decades. And they are safer under ground then above as long as they are marked so idiots don't drive skid steers or tractors or mowers or ATV over them and shear off the fill valves. ( ask me how I know ). Also the temperature underground remains constant year round +/- Your propane supplier can have a technician test your anode bags and advise if they need to be replaced. Its a cathodic protection service call. A dielectric union or pigtail should also be installed at the tank if you have copper tubing from the tank to the second stage.

 

[seville009]

Okay, I can give you one reason: fire protection. If I lived in an area with wildfires, I would much prefer the tank below ground and protected from ambient heat and fire.

Also, possibly cold protection. At very cold temperatures, propane does not convert to gas. One wouldn't want their heating supply to fail on a -20 or -30 F night. Underground would keep it warmer in most Lower 49 geographies.

So there are two reasons although I agree aesthetics are often a primary rational.

Have two 1,000 gallon above ground tanks in Upstate NY - have never had an issue with freezing when it goes below -20. Don’t think we’ve ever had -30, but have had -25, or multiple consecutive days of , say -10 or so.

 

[Oaktree]

Have two 1,000 gallon above ground tanks in Upstate NY - have never had an issue with freezing when it goes below -20. Don’t think we’ve ever had -30, but have had -25, or multiple consecutive days of , say -10 or so.

Was going to make the same comment. I have quite a few outdoor tanks for propane generators at remote worksites on mountaintops, etc. Never once have I had a problem with subzero temperatures. Vaporization temperature of propane is -44°F. Not unheard of in the lower 48, but not common either.

The OP was in Virginia, not a state where wildfires are a big risk. I'm not sure burying would help where fires like parts of California have had lately occur.

 

[ovrszd]

Okay, I can give you one reason: fire protection. If I lived in an area with wildfires, I would much prefer the tank below ground and protected from ambient heat and fire.

Also, possibly cold protection. At very cold temperatures, propane does not convert to gas. One wouldn't want their heating supply to fail on a -20 or -30 F night. Underground would keep it warmer in most Lower 49 geographies.

So there are two reasons although I agree aesthetics are often a primary rational.

Valid points. My shop burned to the ground 12 years ago. 500 gallon tank 20ft from the building. No repairs needed to reuse the tank.

Maybe a "Northerner" on here can comment on the cold issue??

 

[ponytug]

As an, ahem, former northerner, who still gets snowed upon regularly, the downside to LPG in the winter time is that the evaporating (boiling) propane in the tank needs to absorb heat from the environment to evaporate. So, the issue is rate. If you aren't pulling very much LPG off of a full tank at -10F, it isn't an issue. If you are pulling a lot of a close to empty tank at the same temperature, it can become an issue.

Propane Tank Sizing - Tarantin Industries

www.tarantin.com

The takeaway from the top chart is that going from 60% full to 10% full can reduce the available flow rate by half or so. Going from 0F to -10F will also reduce the flow rate by half or so. Net, net, you could lose 75% of the flow rate as the tank empties, and the air temperature drops.

Burying a tank keeps the tank much warmer, reducing the issue. The downside is that you should periodically do a cathodic test on the tank/cathode system. If you can't remember when you did the test, it is time. (In my book, at least.)

And, yes, in any place with wildfires, burying reduces the fire and explosion hazard to you and firefighters. Our above ground tank is well away from the house and other buildings for fire reasons.

All the best,

Peter

 

[ArlyA]

In a fire I thought the tanks pop-off relief would pop and release gas which will burn.... but not "blow up"

 

[groundcover]

As long as the relief device can keep up, gets rather exciting otherwise!

 

[ovrszd]

In a fire I thought the tanks pop-off relief would pop and release gas which will burn.... but not "blow up"

I'd worry more about melting the seals out of the regulator or shutoff valve and releasing the propane at tank pressure and no way to shut it off.

My tank did neither.