purge a oil tank for safty

Wash with plenty of hot water and alkaline solution then pipe in carbon monoxide from vehicle tailpipe.

Sal

Surely you're joking, Sal.

Combined 12% to 75% with air, CO constitutes an EXPLOSIVE MIXTURE.

You got something against dbur177?

--Winston

Isn't CO harder to acquire now that catalytic convertors are common?

Chris

Rumor has it the cat converter reduces CO by 99%.

I'm very literal though. The phrase "...then pipe in carbon monoxide from vehicle tailpipe" cannot be reasonably interpreted to mean "... then pipe in gas largely scrubbed of carbon monoxide from vehicle tailpipe". Even that answer is so dangerous and ill advised that a wise person might call it "not even wrong".

--Winston

If this is a fuel oil tank you don't have to purge it. Just fill it and weld. Don't leave space for air anywhere near the weld site. The fuel will not ignite because of the lack of air. The mix is so rich it won't ignite.

If you doubt this being true then I suggest you don't EVER drive any vehicle with an in tank fuel pump. They run fuel through the motor and brushes to keep them cool and lubed.

The most reliable way is to steam it out, preferably for about half an hour.

Incidently, carbon monoxide is flamable so that is NOT what you are trying to get out of a vehicle tailpipe. What you are after is carbon dioxide. Carbon dioxide will not suport combustion, and is dangerous to you only because it displaces the oxygen in the surrounding air. Carbon monoxide is poisonous. It replaces the oxygen in you blood and the cells in your body die due to lack of oxygen.

I prefer to fill them with water to about an inch of the weld. Second option purge with liquid CO2, get a tank with dip tube or turn bottle upside down. the C02 will not support combustion and the -100 degrees cools the oil so you have little vapor to ignite.

Weld at your own risk.

Thank You, Randy

Remove 333 from email address to reply.

I use CO2 welding, soldering, or brazing gas tanks occasionally. If you don't have a bottle handy buy some dry ice at Baskin Robbins and drop it in, leave it long enough to melt with tape loosely covering the holes, so gas pressure can escape as it melts, and when heat is applied. The preferred method would be to solder using a large electric, or coppers heated some distance away and relayed by an assistant. Even better, get the assistant to do it lol.

The pipeline crew would weld patches onto 3.5 million gallon gasoline/fuel oil tanks regularly. The usual reason was someone had shot a hole in the tank. The SOP was to pound a plug into it and let the outside dry, then weld a plate over top of it.

The rules required the weld site to be X feet below the top of the product; i.e. submerged on the inside. I can't recall how many feet X was.

JR, Puleeze.

Car exhaust is just not safe. Other suggestions in this thread are much more compatible with continued breathing.

If dburl177 wants to purge with CO2 or water or argon in a well ventilated, above ground work area, that'll work just fine. Pardon the sensitivity but I lost a friend a couple months ago due to car exhaust. Granted, he made an informed decision and hopefully passed away peacefully.

I don't think that was the OP's goal though.

--Winston

Heating Oil AKA #2 Distillate AKA Diesel Fuel? That stuff is very difficult to light off in a tank like that - look how hard you have to work to make it light when you DO want it to burn... A simple purge of the tank with any handy and appropriate inert gas will work.

Carbon Dioxide is the easiest and cheapest, either from dry ice or cryo liquid (if you have it) or a bottle. Nitrogen works if you have a separator system, or from a compressed bottle, or from liquid nitrogen. Or Argon or Argon/CO2 welding mix...

It's the more volatile things like gasoline you have to be more paranoid with your precautions - and even then you need free fumes and oxygen to make it go BOOM! If the tank has no free oxygen in it (only gasoline and gasoline vapors) and you don't let liquid fuel or free vapors out to mix with atmospheric oxygen, no go BOOM!

Steam would even work if you provided a continuous low pressure supply to purge air.

(Don't restrict the vent with a check valve, the steam stops and the tank implodes. Fun to watch on 'Mr. Wizard' or 'Bill Nye the Science Guy' as a demonstration, not so fun on /your/ gas tank.)

NOTE: Even though you purge the tank, you DO NOT do this alone. Have someone stand Fire Watch behind you as you weld, with a big-ass fire extinguisher or two (that they know how to work!) at the ready. With the mask on, you can't see when the fire starts at the filler neck because it isn't in your field of view.

And tell a third worker nearby (or your neighbor if this is at home) what you are doing. "If you hear us yelling FIRE! we aren't joking - call 9-1-1 First, investigate second."

And have a few more extinguishers strategically placed along the retreat routes, this is one of those times you can never have too many. So once you've turned off and dropped the torch and gotten back from the fire, you can join in the festivities. You'll have the protective welding apparel on so you can safely get a bit closer.

-->--

Last I knew it was based on product type in the tank.

On a small pinhole leak you can use plain Ivory soap. The fats used making the soap will react with the petroleum and swell to seal the leak.

I'm not suggesting he stick the pipe in his mouth.....yet. JR Dweller in the cellar

W>

Kind of interesting to watch this thread as pumping engine exhaust into fuel tanks is exactly what many ships that transport hydrocarbon liquids do and have done for many years.

Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)

(...)

Bruce, can you help me understand your point please?

I can think of a couple other things routinely done by professionals with acceptable safety, that probably shouldn't be done by untrained individuals using casually assembled equipment. I am sure you can as well.

I for example, being one of those untrained individuals with casually assembled equipment probably shouldn't put together a liquid fueled rocket. I realize that amateurs have done that.. (5320 Google hits just now). I'm just saying that I would be asking for trouble by doing so, without first gaining significant knowledge, much of it safety - related.

I could, conceivably drive my car in front of a speeding train to rehearse for an amateur stunt movie. Would that be a wise thing for me to do? Nuh uh.

Advising someone to do something in a risky way, particularly when there are several much safer ways to do it, is irresponsible.

If you are just yanking me, that's cool.

I'm just concerned about those folks who are as literal and trusting as I am.

--Winston

Rather a complex response to a simple exchange.

The poster says "Car exhaust is just not safe. Other suggestions in this thread are much more..."

I simply point that it isn't intrinsically unsafe as ships have been doing it for years and, probably will continue to do it as it is the cheapest and easiest method so far developed.

Now, if you really think it is necessary to qualify the statement with something like "I know youse guys are a bunch of idiotic stumble bums that don't enough sense to come in out of the rain and are so fumble fingered that you can't hit you ass with both hands", just let me know.

Until you do I'll continue to consider the denizens of this group as normally adept craftsmen.

Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)

(...)

Apt though, Yes? :)

Quoting the OP, verbatim: "whats the best way to purge so that a welding spark wont blow me yup kapow not ready to die today may a eathquake or flood torado no blown to out of orbit"

Quoting Sal, the first responder (pun intended): "Wash with plenty of hot water and alkaline solution then pipe in carbon monoxide from vehicle tailpipe."

Ships have not been displacing air in fuel tanks using CO. Not intentionally anyway. We would have heard, perhaps individually, in the first person.

Note that I didn't say anything about use of CO2.

My point was that: "Combined 12% to 75% with air, CO constitutes an EXPLOSIVE MIXTURE." Grumpy mentioned that it is poisonous, as well.

Jeeze Bruce, who implied that?

Like all newsgroups, RCM comprises a wide variety of individuals of varying experience and capability. I like to think that they self- select for many desirable traits, among them, intelligence, a thirst for knowledge and a hands-on attitude. They, with very few exceptions have earned my admiration and respect. I hope to continue learning from all these smart people.

Doubtlessly, most are, on average. Some are geniuses. Some, (myself included) struggle on, using the FSM's meager gifts as well as they can. At best, it's a mistake to tell people something that is likely to hurt them, particularly if much safer methods are available.

Level check...Test TEST One Two. Is this thing on? :)

--Winston

CO is used as fuel in heat-treating furnaces. If you want to end it all, it's a fair choice, if not a good one.

-- Ed Huntress