Gasoline storage

I hate it when someone questions what I have accepted as fact for decades.  I have an above ground gasoline storage tank. It has a vented cap on it.  A friend dropped by today and questioned the need for the vented cap.  He says he has an above ground tank with a solid cap.  He removes the cap to temporally provide a vent when he wants to remove gas.   Otherwise he keeps the solid cap in place to reduce evaporation.

Opinions?

Tanks are expensive.  Remediating leaks/spills is even more so.  Gasoline expands a lot in direct sunlight, even at modest temps.  The pressure build and contract contributes to metal fatigue, increasing the likelihood of leaks.  The amount of gas venting vs service life of a tank may be a false economy.  Maybe not.  Hard to tell.  How often does one fill or dispense fuel?  How thick is the steel of the tank?  How good was the welder building the tank?  How many expansion cycles per year does it experience?

Too many variables to know for sure, but a lot of bad stuff if you get a leak.  Even with an unvented cap one will lose a good volume of vapor when the cap comes off to fill or relieve as the pressure inside and outside equalizes, so not venting seems moot to me.  On the other hand vented caps have more to do with safety regulations than anything else (can't imagine vaper locking an entire storage tank.)  If there is no ignition source when opening the cap high pressure vapor should not be an issue.  Now if you have to take a wrench to turn the cap when it is under pressure and you spark....  

What a self righteous prick!

Nah, I think he's probably right. Especially with ethanol gas and it's water attracting characteristics. I can see no reason to leave a vent open at all times. Maybe you can hook a hose with a valve on the end to the vent so you can quickly open and close it at ground level? Not sure how accessible your vent is.

The tank needs to breath as the gas changes temps.  They do make caps that have absorbent silica gel in them to help keep the tank from breathing in moisture.

Hmmm,

Maaaaybe, possibly, occasional pumping from the tank relieves the pressure that makes the vent necessary in the first place?  Not certain on this one.  Personally, I think that the vented cap is a sound idea.

Also a sound idea--keeping your gasoline stored OUTSIDE and away from your house/garage/barns/etc.  I should be so thoughtful.  I have a bunch of gas and diesel cans that I keep inside my garage.  Sounds like you have removed a fire hazard, so good for you!

Eric

Hi Eric,

I’m talking about. 350 gallon above ground storage tank.. it is pretty thick walled. I bought it for around $50.   It paid for itself this year by me using the gas I bought at $2.85.   Of course, I am waiting for a dip to replace what I have used.  By any means, I have always used a vented cap. …but a person who stopped by led me to wonder if I needed the vent in place all the time.

John,

I was pretty sure I knew the type of tank you were talking about.  There are certainly times when I wished I had one of those as I really don’t like filling 5 gallon cans at the station and bringing them home inside my vehicle. Nor do I like dumping tanks upside down to fill up my mower, tractor, etc.  I recently did get a fuel pump to ease filling up my tractor—I connect it to the tractor battery, dip a tube into the can, stick a nozzle into the tank and pump away!  It certainly beats tipping a can!

But back to being on topic, in hindsight, I think the vented cap is probably a good idea.  Maybe, just maybe you could get away without one if you were pumping very frequently and “venting” through pumping, but that is just speculation on my part.

Nice score that you got the tank for $50! I have looked for those and found them to be pricey when purchased new.

Eric

Mine was used.  The guy had a little less than a dozen he had picked up at some sale.  It had held oil.  Anyway he needed $50 more than he needed that tank.  I have learned to keep a mental list of many things I would like to have.   Then, I take advantage of targets of opportunity.   I can more easily walk away from something I want than when I shop for a specific item that I must have.

How do you get it filled?  Does a truck come out?

Originally, I combined my delivery with my big farmer neighbor.  I had to pay the taxes, but I saved on delivery costs.   I poured in a bottle of PRI-G for safety.   After that, I have used a variety of options. I check the tank once a year ( I live around 60 miles from a Costco, so when I travel to the big city, I fill up my car there).  Anyway, if the tank is really low, I coordinate delivery with my neighbor. If it is a little low, I usually fill up a few 5 gal cans and fill it up myself. Of course, I have a truck that makes carrying gas a little less exciting than what you experience.

BTW…..did you ever see the security video of the guy putting several cans of gas in his van and then stopping to light up a cigarette?

John F Dean wrote:
BTW…..did you ever see the security video of the guy putting several cans of gas in his van and then stopping to light up a cigarette?

No, but I saw the one where the guy was filling up and noticed there was a spider next to the pump nozzle and decided the proper way to kill it was with a cigarette lighter!

It’s a good thing I don’t smoke!

More seriously, I have considered buying a 25 or 30 gallon fuel tote from Northern Tool to use as storage instead of 5 gallon cans.  Of course I would use my fuel pump to actually move the fuel into the tractor.

The biggest problem would be filling the tote—do I really want to fill this while it is sitting in the back of my van?  And then getting the fuel and tote out of the van and onto the ground—that’s over 150 pounds!  I could use the tractor bucket, but by now, the 5 gallon cans don’t look so bad!

Eric

Eric,

I assume your tractor uses diesel.   I have a 55 gallon drum with a hand cranked pump sitting near the door of my barn. The drum sits on a pallet.  Yes,I filled it by hand hauling containers. But, once again, I bought fuel when it was cheap.

To add to the horror stories. In MN, I used to volunteer on a bookmobile.   There was an old run down gas station across from a restaurant where we used to stop for a coffee break.   One day, the gas station was gone. Of course we asked.  As near as anyone could tell, the new hire decided to wash the floor of one of the bays with gasoline and the furnace kicked in ( the overhead type often seen in workshops).

A local story from my parents' time: there was a small gas station locally with no roof over the pumps like modern ones have. One winter the ground was covered with a layer of ice making it pretty slick for people driving and stopping/starting around the pumps. The attendant decided the simplest way to remedy the situation would be to squirt a layer of gasoline over the pavement and light it...you can't make this stuff up!