Storing gas in a propane tank?

   / Storing gas in a propane tank? #1  

zmoz

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I want to install a ~250 gallon gasoline tank at my shop to be filled by a company really near by. I'm wondering if I could store it in a slightly modified propane tank, rather than a standard liquid fuel tank. I would completely close up the propane tank when not in use, no vent or anything, so as to prevent condensation and water buildup.

Would it be ok to store gas completely sealed up tight like this? I mean, is it any more dangerous than the propane the tank was designed to hold? I'd probably have a high pressure safety blow off valve of some sort, but I doubt I would need that with gas.

I'm also thinking if it looks like a propane tank, nobody is going to try and siphon of a few gallons into a can. ;) Empty gas tanks have been a big problem around here....
 
   / Storing gas in a propane tank?
  • Thread Starter
#3  
Another thought - what if I pressurize the tank to a very low pressure with a CO2 tank? I could use that instead of an electric pump for fueling, and, no air in the fuel tank either. Kind of like a beer keg. :)

As for storing gas, isn't the best thing to do is keep regular air away from it as much as possible?

Unfortunately we're only allowed 10% ethanol mix around here, I'm still trying to see if I can get some kind of exemption for "offroad" use. ;)
 
   / Storing gas in a propane tank? #4  
zmoz, Something a gas (propane) man told me years ago, by best recollection, is that propane tanks are raw steel inside because propane is a very dry & noncorrosive product. Gasoline with alcohol is neither. Life of the tank may be short ??? However, the concept seems worth persuing. Keep us posted. MikeD74T
 
   / Storing gas in a propane tank? #5  
Your question got my curiosity going. Just my first thoughts is if it is fairly full you might want some sort of pressure relief valve when it is sitting in full sunshine. That should relieve well above ground level so as to not pool fumes near the tank. You would want a good static ground system for the tank and hose.
I didn't find anything on Google about storing in propane tanks. I did find a discussion about storing gas in general which was a fun read.
Storing gasoline for shtf. - THR
 
   / Storing gas in a propane tank? #6  
just off the top of my head, you would definitely want a pressure relief valve. it doesn't have to be an open air vent, but something that blows off at 10-15 psi would accomplish your goal of keeping the fuel pressurized and outside air from entering the tank.

be careful what you use for pressurization. don't know if co2 dissolves in gas to an appreciable amount, but could form carbonic acid if any moisture is present in the fuel, then watch out corrosion! perhaps n2 or argon would be a better gas to pressurize with? or just use dry, compressed air if using the fuel fairly quickly.

as mentioned, epa can get expensive quickly if you have a leak. sometimes metal tanks are required to have bathtub retaining walls built around or under them as a secondary leak containment structure. this is especially important near water body such as lakes and streams.

amp
 
   / Storing gas in a propane tank? #7  
I suspect that you would be far better off to use a gasoline storage tank made for the purpose.

The only real reason to even think about using a propane tank is if you already own one and can modify it at low cost. However, you can probably sell one for what a real gasoline tank would cost.

Some tractor-trailer rigs have aluminum diesel tanks which make up into very nice storage tanks. They can be used for gas if the diesel is cleaned out. Don't know about prices, but one from a wreck could be good.
 
   / Storing gas in a propane tank?
  • Thread Starter
#8  
zmoz, Something a gas (propane) man told me years ago, by best recollection, is that propane tanks are raw steel inside because propane is a very dry & noncorrosive product. Gasoline with alcohol is neither. Life of the tank may be short ??? However, the concept seems worth persuing. Keep us posted. MikeD74T
That is true, but so are regular gas tanks. That's why they rust out after time. :) That's why I have to be careful to keep water out - but I don't want water in my gas in the first place!

as mentioned, epa can get expensive quickly if you have a leak. sometimes metal tanks are required to have bathtub retaining walls built around or under them as a secondary leak containment structure. this is especially important near water body such as lakes and streams.
I'll look into what the fuel delivery guys say...though I am in industrial zoning, so I get away with a lot. :)

I suspect that you would be far better off to use a gasoline storage tank made for the purpose.
Except those are not completely sealed, and cannot hold any vapor pressure...plus, much more likely to be stolen from. If people think it's a propane tank, they're also probably going to think they can't fill a bucket with it. ;) With a propane tank I'm looking for something used, maybe even past it's pressure testing date, since I don't need it to hold 250+ PSI. If I got a regular gas tank around 250 gallons it would have to be new, and probably cost nearly the same.
 
   / Storing gas in a propane tank? #9  
The commercial zoning my actually have more stringent fuel storage requirements. At the very least I suspect they'll require placards...so everyone will know its gasoline anyway.
DO NOT use compressed air to pressurize your tank. Doing so could cause static build up. That would not have a happy ending.
Talk to your fuel supplier. He can tell you if the rig you want is even legal. No sense building a rig you can't get filled.
 
   / Storing gas in a propane tank? #10  
Remember c3 tanks are originally purged of air before they get put in service so there can not be a combustible environment in the tank.

I'd suggest a vent just like an ordinary fuel tank sized for your tank. If not vented there could be times the tank will be in a negative air presser state for which it may not be designed. There may also be fuel delivery problems when it is in this state.

Put on a drop leg with drain valve for a water accumulator.

Consider mounting it on a stand for gravity feed on the fuel nozzle???:confused:
 
 
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