Storing gas in a propane tank?

[zmoz]

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....

 

[Mighty Dodge]

I don't see why it wouldn't work.

M.D.

 

[zmoz]

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.

 

[MikeD74T]

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

 

[Treemonkey1000]

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

 

[ampsucker]

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

 

[CurlyDave]

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.

 

[zmoz]

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.

 

[Pops15]

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.

 

[Egon]

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???

 

[coreshot]

They also make a product for lining gas tanks to prevent them from rusting out. It is used in motorcycle production quite a bit. If you had a way to get inside the tank and coat it, it would eliminate several issues. When doing bike tanks, you just dump it in and shake it around to coat it, then dump out the remaining product. Once it has cured, you're good to go.

As said before, I'm sure your supplier has a list of regulations as long as your arm for what type of container he can fill. Ask him.

 

[Pops15]

If I got a regular gas tank around 250 gallons it would have to be new, and probably cost nearly the same.

Why would it have to be new? I see used tanks at farm and commercial auctions quite often.

 

[ctgoldwing]

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.

+1
Years ago I had a large gasoline generator (Ford 292 in it) hooked up in my garage. I solved the gas storage problem at a local marine supply store. He had several 50 gallon aluminum tanks that were rectangular & low (as I remember they were about 4 feet long, 12 inches high & 18 inches deep). He had several and I bought one for $50. He told me at the time that he always had them available, cheap, in different sizes. Might be worth a look?

 

[zmoz]

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.

Unfortunately that won't work with the ethanol mix they pass off as fuel around here, water is absorbed into the fuel completely and doesn't sink to the bottom. (unless it's REALLY saturated)

That also may be a good idea for a CO2 or other inert gas fill at low pressure, have a regulator set to keep it at like 10 PSI at all times.

+1
Years ago I had a large gasoline generator (Ford 292 in it) hooked up in my garage. I solved the gas storage problem at a local marine supply store. He had several 50 gallon aluminum tanks that were rectangular & low (as I remember they were about 4 feet long, 12 inches high & 18 inches deep). He had several and I bought one for $50. He told me at the time that he always had them available, cheap, in different sizes. Might be worth a look?

If I could find 'em that cheap I'd buy a bunch. Never seen anything like that around here. I need tanks for my boat too, and even the plastic ones cost more than that from what I've looked at.

 

[Eagleview]

In Australia , it is illegal to store any more than a couple of gallons of Petrol/Gasoline because of the fire hazard risk .

As for using the Propane tank , If Firemen were to attend a fire at a house with a Propane tank outside , they would have standard procedures to handle that particular risk . If by luck or by bad luck they found out the tank had Gasoline in it , you would never see daylight again , especially if someone got hurt .

 

[zmoz]

As for using the Propane tank , If Firemen were to attend a fire at a house with a Propane tank outside , they would have standard procedures to handle that particular risk . If by luck or by bad luck they found out the tank had Gasoline in it , you would never see daylight again , especially if someone got hurt .

Do firemen naturally assume that propane tanks full of, well, propane, are safe when they're burning? Or back to the first question I asked, is a tank full of gasoline anymore dangerous than a highly pressurized tank of propane?

I understand storing gas, in general, is dangerous, but, I also know that millions of people have a propane tank in their yard or a diesel tank in their basement...I don't see those as being any safer.

The only advantage propane might offer is that it can't "drip" out and contaminate the environment. Also, I'm thinking about getting a propane tank for propane, too, so it would be kind of nice if both tanks matched. Maybe even paint the gas one red, and wait out there with my .357 for the theives...

I still don't know what exactly all the regulations are, but, I do know from my shop I can see the refueling tank for the local school bus fleet, above ground, a couple thousand gallons, maybe 500 feet away.

 

[ultrarunner]

They also make a product for lining gas tanks to prevent them from rusting out. It is used in motorcycle production quite a bit. If you had a way to get inside the tank and coat it, it would eliminate several issues. When doing bike tanks, you just dump it in and shake it around to coat it, then dump out the remaining product. Once it has cured, you're good to go.

As said before, I'm sure your supplier has a list of regulations as long as your arm for what type of container he can fill. Ask him.

The shop where I worked in the 80's sold a lot of the fuel tank sealer... it worked great until reformulated fuel hit the marked... it turns the sealer into a glue like glob....

I had a problem and contacted the manufacturer and said it was never designed for use with alcohol...

 

[ultrarunner]

DO NOT use compressed air to pressurize your tank. Doing so could cause static build up. That would not have a happy ending.

I have several Model T Fords and they use compressed air to pressurize the fuel tank when going up steep hills... normally the fuel is gravity fed unless the hill is steep... the other alternative is going up in reverse putting the fuel tank higher than the carburetor...

The system pressurizes 1 to 2 pounds...

 

[zmoz]

I have several Model T Fords and they use compressed air to pressurize the fuel tank when going up steep hills... normally the fuel is gravity fed unless the hill is steep... the other alternative is going up in reverse putting the fuel tank higher than the carburetor...

The system pressurizes 1 to 2 pounds...

LOL, that's funny. I've heard about the going in revers thing. I'm sure they weren't worried a whole lot about whether it exploded or not though.

 

[zeuspaul]

I recently spent quite a bit of time researching storing gasoline as I need it for my home defense fire pump. A few comments that may or may not be of use.

I would make sure your supplier will fill the tank. I recall a limitation of 60 gallons for home storage. It may or may not apply and I don't recall whose limitation it is, it may have been the EPA. There can also be insurance implications for larger amounts of stored gasoline.

You can get a vent for a 50 gal drum for petroleum storage. It vents pressure at 5 psi and vacuum at 4 psi. Justrite drum vents.

I believe gasoline is best stored under pressure. Vapor pressure of reformulated gasoline varies but seems to max out at about 17 psi at 100F. Winter gas has a higher vapor pressure than summer gas. I believe venting is recommended in case of fire to avoid explosion. I plan on venting at 17 psi in a 9 gal tank. I may try one of these diesel fuel check valves. Check Valves & Pressure Relief Valves for Diesel Fuel

A lot of sources recommend stabilizers if stoing more than three months or so. Chevron's web site indicates you can store their gasoline for a year. I plan on using Pri-G stabilizer.

Zeuspaul