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OT:Cuttin up an Anhydrous Ammonia tank............

david n

Diamond
Joined
Apr 13, 2007
Location
Pillager, MN
Is there any worries on cutting up a decommissioned anhydrous ammonia tank? Any residual AA? Tank is empty and valves/plugs are pulled already. Basically I can have it for scrap, just want it for the heads and a ring or two for backyard fire rings.
 
I cut an old gas tank with my plasma cutter....I filled it with water.

After the first pierce, it kept cutting nicely as the water rushed out of the kerf
right behind the torch.

yes, the hose kept filling it the whole time.
 
yes ,fine spray of water washes it all away.....I used to work at a fridge plant used ammonia,they had an emergency compressor driven by a 6 cyl Ruston and Hornsby big as a bus.........when there was a ammonia leak over night or weekend,the cops would let you know.
 
yes ,fine spray of water washes it all away.....I used to work at a fridge plant used ammonia,they had an emergency compressor driven by a 6 cyl Ruston and Hornsby big as a bus.........when there was a ammonia leak over night or weekend,the cops would let you know.

(my italics)

IME Ruston & Hornsby never built anything small, ……….even their small power engines were massive for what they were.

IIRC A lot of Ruston Bucyrus cranes were fitted with R n H diesels, which seemed to run for ever.
 
Is there any worries on cutting up a decommissioned anhydrous ammonia tank? Any residual AA? Tank is empty and valves/plugs are pulled already. Basically I can have it for scrap, just want it for the heads and a ring or two for backyard fire rings.
Anhydrous ammonia is really volatile and any remains should turn to gas and vent off.

If the tank is dry from inside and ventilated to atmosphere already its just a empty tank. If it is containing any water that could have dissolved ammonia left.
 
Anhydrous ammonia is really volatile and any remains should turn to gas and vent off.

If the tank is dry from inside and ventilated to atmosphere already its just a empty tank. If it is containing any water that could have dissolved ammonia left.

The concerns are:
Upon cutting with thermal means, more of the chemical leaches out and becomes a new hazard (even after cleaning)
The container is not "open" enough to allow an ignition of any residue to just "woof", small fire.

It's the first cut that is the problem.

If it's the ends your wanting to save, I would do the initial cut to remove
the area of the valves in the center. making a cut about 18"-24" in dia.

After this piece is cut out, the explosion hazard is much less.
 
Anhydrous ammonia shouldn’t ”leach out” to any troubling degree so its different from old oil tank or such. If there is additional half inch layer of bitumen or tar its different case.
 
Anhydrous ammonia shouldn’t ”leach out” to any troubling degree so its different from old oil tank or such. If there is additional half inch layer of bitumen or tar its different case.

Tell you what.

I'll give you the torch/plasma cutter and you walk up to an "empty" 1000 gallon tank, and start cutting on it.....:skep:

And I'll go dial 9-1.....
 
Yeah, there might be other chemicals left in ”empty” tank with unknown history but not ammonia. Cutting cast iron water pipes is also unsafe if someone has filled them with old dynamite.. ;)

Ammonia is not problem for torch cut if you manage to breath next to the ventilated tank... odor threshold is 10000 times lower than lower explosive limit.
 
Yeah, there might be other chemicals left in ”empty” tank with unknown history but not ammonia. Cutting cast iron water pipes is also unsafe if someone has filled them with old dynamite.. ;)

Ammonia is not problem for torch cut if you manage to breath next to the ventilated tank... odor threshold is 10000 times lower than lower explosive limit.

You say all these things....How many tanks have you put a torch to ?

I have cut:
1. a 300 gallon skid tank that had contained gasoline
2. a 25 gallon chevy truck fuel tank that was just emptied of gas.
3. An acetylene tank (and then welded on it to)
4. A couple of 55 gallons drums with motor oil residue still in them.

You really, really need to stop filling the internet with dangerous practices
that are gonna get someone killed.
 
The Ruston was originally direct air start,but the HP compressor packed it in,and we rigged up a Indian Chief motorbike to run its back wheel on the flywheel....started the Ruston ,easily......One time ,the bolts holding the flywheel sheared,and the flywheel took off like a 10 ton frisbee,dragging part of the compressor.Did a fair bit of damage......after that ,there was a concrete wall built beside the fly wheel.
 
Why,
Even if safe at the price of a fire ring is it worth the cutting gas, time and effort?
I get the hacker idea in spades and like but sometimes the effort is just not worth it.
That said I've often gone down this road.
Bob
 
Some Perspective...

Across the street from my shop last week there was some work going on...
I looked over the see what was going on and it was like a Road Runner illusion. I couldn't focus my eyes on something.

A 35,000 BBL gasoline tank (Huge! about 1,470,000 gallons ) had a hole cut into it, maybe ten feet square.
So they could drive a skid steer into the tank and clean out the bottom, or whatever it is they were doing.
They did not consult with me.
When they were done, they slapped the section back into place, and welded it all back up, and looks like some primer on the weld joints.

Just think about that..... A huge gasoline tank at a gasoline pipeline terminal, cut open, work done inside, and welded back up again.
I am real sure they did not fill it with water first!

But again, Don't Try This at Home.
 
Why,
Even if safe at the price of a fire ring is it worth the cutting gas, time and effort?
I get the hacker idea in spades and like but sometimes the effort is just not worth it.
That said I've often gone down this road.
Bob

I'm with Bob, seems like a big PITA for a fire ring. I'd go down to the local farm store and get one of those galvanized rings they have that's used for livestock.

Brent
 
Some Perspective...

Across the street from my shop last week there was some work going on...
I looked over the see what was going on and it was like a Road Runner illusion. I couldn't focus my eyes on something.

A 35,000 BBL gasoline tank (Huge! about 1,470,000 gallons ) had a hole cut into it, maybe ten feet square.
So they could drive a skid steer into the tank and clean out the bottom, or whatever it is they were doing.
They did not consult with me.
When they were done, they slapped the section back into place, and welded it all back up, and looks like some primer on the weld joints.

Just think about that..... A huge gasoline tank at a gasoline pipeline terminal, cut open, work done inside, and welded back up again.
I am real sure they did not fill it with water first!

But again, Don't Try This at Home.
More than likely they used a monitor to make sure the atmosphere was sufficiently below LEL and that's not something most folks have at their disposal.

Also, they could have flooded the tank with nitrogen prior to commencing work. 35k bbl is about 200,000 cubic feet, well within the volume of a single ln2 transport.

As an aside- should anyone have to cut into a vessel of unknown presure or contents there is a (relatively) safe way to do it. Grab your side grinder and begin grinding a small spot into the wall, paying particular attention to the freshly gound steel. When the steel discolors from the heat of grinding STOP. Place a sharp punch or chosel in the center and give it a whack, it will pierce the steel revealing to you whether or not it's fully evacuated.

Same method can also be used to create a large window, more grinding though.

Sent from my SM-G973U using Tapatalk
 
You don't state the size of the tank, but it was about a 300 PSI pressure vessel. It will be heavy and may not be worth it even at scrap price.

As for using a galvanized tank from the farm store, no, I would not use anything galvanized to make a fire ring.
 
My neighbor weld shop makes fire rings.

plasma cuts side as one big 12-16" wide 1/4" plate about 10' long
Has wildlife scenes.

They roll them, about 3' dia., and then weld on a top, this part is round on the outside, hex shaped hole for the fire, with "your name here"
plasma cut on it.*

* they keep a brand new one painted gloss black (I sandblasted it for them) with "Your Name Here" plasma cut in the top, take it
to the annual RMEF get together, sell raffle tickets with it.

Winner gets a custom one with their name on it.
 
The jamokes near me make large vessels...it's common to see a 16 foot diameter, or larger, that's 30 or 40 feet long. They make smaller tanks, too.

As part of their normal operations, they scrap tank ends fairly regularly. Either QC issues or they damaged them or whatever. So there's a pile of them sitting there. They came up with the idea of making fire rings out of them, like a million other people.

The problem is...the place was taken over by the owner's sons who quickly decided they were bad-ass artists, country boys who knew a thing or two, and they would drive their lifted diesel F-250's and sell fire pits to the stupid city folk.

The end result is....I asked how much for a scrapped, smaller tank end...maybe 6 feet or so. The old boy tells me, "Oh, a couple thousands dollars..." Keep in mind this was not a finished product, just the tank end bare and rusty.
 








 
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