How would you cut the top off a 500 gallon underground gas tank?

You hope.

In theory, or under precisely controlled conditions, yes you can extinguish a burning match in liquid gasoline. In practice...?

I sure don't want to be there the day someone tries that cigarette trick and the vapor recovery system is screwed up, to where it has sucked in an above-LEL level of atmospheric oxygen in the tank.

They'll hear that sucker go BOOM! in the next state, and they'll be picking up pieces of the delivery driver with tweezers.

"No brains, No headaches."

-->--

Years ago when I drove taxi, another driver fuelled up his propane powered cab one winters day.

The overflow valve had frozen shut so the driver bent over with a bic lighter and decided to thaw it out.

It thawed.

No - It didn't go kaboom, but he lost all the hair on his face and suffered some interesting burn patterns in the process.

Yah I know it's a little off the subject but this thread has brought back some interesting recollections of my days of driving propane powered taxis.

I'm not comfortable with the idea of betting airing out will do the job well enough. Too many tanks started stinking after they set a while, no matter how well I aired them out, or washed them out. (Unless I used really hot water.)

That can be tricky to find. Gell ice is air shippable, dry ice is not. Some places quit carrying it.

| >> One trick I've seen is to run a hose from an exhaust pipe of | >> a running | >> engine. The exhaust gases will drive out the gas fumes. | >

| > Even easier (and safer) would be to put down a hose from a compressor, | > and let it pump air for a day, while at the same time trying to smell | > the air coming out. I would think that if there is no perceptible | > smell, including from an air sample from the bottom, there should not | > be much risk of an explosion. But, better safe than sorry. | >

| > i | | The exhaust idea sounds a lot better than the compressed air. | | Haven't you ever seen the fuel delivery guy drop his cigarette but down the | hole at the gas station? No air down there to support combustion...

And you sat around, watched and did nothing?

| >> Even easier (and safer) would be to put down a hose from a compressor, | >

| > A compressor does not pump enough cubage. They are intended for pressure. | | Mine pumps about 11 cfm at about 120 PSI, continuously. It is about | 100 CFM uncompressed. I would say that it is quite a bit. After a day | of pumping, it would pump 144,000 cubic feet of uncompressed air. For | a 500 gallon tank, which is 70 cubic feet, the day of pumping is 2,000 | times the volume of the tank.

Unless you have a sure way to verify that the tank is gas free you have better odds in Vegas. At least there you lose only your money.

I guess I should pipe up here since this is an area I have some experience in. When we remove underground tanks for disposal, we throw a pile of dry ice in prior to doing anything. The idea is that the CO2 released will gradually fill the tank with a gas which does not support combustion. I have never had to cut into an UST, the dry ice is added just for digging it out safely. Cutting into one sounds like it could evoke the Darwin Effect. Good luck.

John

davefr wrote in news:r84731pp2go7hd9vte21kr93r0q36llb2l@

Pretty good guess. 500 gallons = 2.48 cubic yards.

Dan

Thanks for all the replies. The job is done.

I used the dry ice method to purge the fumes. Then I used my cordless Sawzall to decapitate a 2' X 6' section of the top. (it actually cut easier then I thought). The inner walls and bottom looked clean and in good condition so I just filled it with dirt and compacted it as best I could.

Cost: $15 for 10# of dry ice $8 for a 5 pack of bi metal Sawzall blades. About $5 in tractor diesel getting fill dirt $28 Total (not including a couple gin and tonics for my sore back)

He lit

A match

To check

His tank.

That's why

They called him

Skinless Frank.

BURMA SHAVE

(Seen from the backseat of a '56 Pontiac somewhere in Southern Illinois, about 1958).

Garrett Fulton

fill it with concrete? Pat

I don't know where you are, but try:

Why not just dig the D*** thing out and be done with it. If you try to hide it, it will come back and haunt you! Gerry :-)} London, Canada

They are filled with sand and plugged. - GWE