Cutting Open Old Propane Tanks

[Sbi1]

Written Procedure

I finally found a written procedure for this (I knew I had seen it before, just couldn't remember where). This comes from the National Propane Gas Association bulletin #132-91, Recommendations for the disposition of unservicable LP-gas cylinders. "Thoroughly purge the cylinder before making any attempt to destroy it with a cutting torch or other device. Purging can be accomplished with the use of inert gases, steam, or by completely filling the cylinder with water." "Once the cylinder pressure has been reduced to the atmosphere and the cylinder has been purged, a test should be performed to verify that it is free of a combustible gas mixture before disposal. A combustible gas detector may be used for this purpose". That is the most relevant part of the bulletin-I would post the whole thing, but my scanner died. If you would like a copy, Pm me with a fax # and I'll send it to you. This is the only written procedure for disposing/cutting a propane tank that i have ever seen.

[garybdavis]

SBi1,

That's exactly what I'm looking for. I went to the NPGA web site but couldn't find that publication - I think you have to be a member to download it.

I also found references to this publication:
Item: 000130
Title: Purging LP-Gas Containers

I'm going to give them a call tomorrow and see if I can order them. If not, I’ll take you up on your offer to fax it.

[fyoung]

added link to welding manual

[QUOTE=garybdavis]
Gary, I have a Military CD (Welding,Stick,Mig &Tig)that explains how to do it and it also has a bunch of other things about welding that I'd be glad to email you or anyone else wanting it..I bought it but it says it can be distributed freely because it's public information. The method they say use is the same as my cousin used for many years at a large welding-fab shop and he never had any problems with this method. Basically you drain the tank and flush with plenty of water and then hook a car exhaust to a steel flexible pipe and run exhaust into the tank for several minutes to purge the tank then start cutting after checking with gas detector...My cousin kept the exhaust running into the tank while he cut or welded because he said the exhaust had carbon monoxide in it and wouldn't let anything burn because it took all the oxygen out of the tank and you got to have oxygen to burn or explode. I myself have welded and cut on a few tanks doing this but was always nervous while doing it. As the old saying goes please don’t try this at home! Anyway it says you can also use steam, I’ve never tried that but the car exhaust thing always made me feel a little bit better thinking it was taking the oxygen out of the air too. I don’t think there is a 100% safe way to do it. I got a friend here locally that has been welding since he was a kid and has a large welding-fabrication shop and a few years ago he burnt about half of his shop up cutting open a propane tank and he had cut hundreds open...no telling how many small ones he cut open to make feed troughs out of. Like I said I’ve did it before and I’ve got a 540 gallon propane tank right now that needs the ends cut out but I’ve decided I’ll rinse and purge with exhaust and leave the exhaust running and cut the first end out with a saw…I want to live to see the grandkids grow up and marry *LOL*
I also have a friend that had did this hundreds of times and he uses a lawn mower exhaust on the smaller tanks.
Guys here's link to a welding Cd with info on this and a bunch of other things..I'll leave it up for a few days so feel free to download it. Hope this helps, Farris



here's the link

http://rectorenglish.0catch.com/users/fyoung/index.php

username : welding
password : arkansas
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A Friend, Farris


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[fyoung]

Illegal

Can I add to the question? How would you safely cut open a refrigerant container. I have some (look like 20lb propane tanks, but green) that I would like to cut and use. I think they are from R12, and are empty.

Thanks,
Joshua

Be careful cutting refrigerant tanks open because it's against the law (EPA)
They put a local man out of business for doing that..they fined the heck out of him and he fought it and spent a bunch of money and still lost. They said some of the tanks still had some in them and he was releasing it out into the air.
Hope this helps, Farris

[T_Bone]

You need three items to have an explosion with a carbon base fuel

Oxygen, Carbon, Ignition

O/A= Oxygen Acetylene

Think about the above for just one minute and see if it doesn't dawn on you what your fixing to do!

Well I'm removing the Oxygen! yep you sure are and as soon as your torch pops out during the cut, it'll filler right back up with?..... with?...
Oxygen and Carbon

There's been more than one person from heaven that stated:

Gee's I wish I wouldn't had done that

[Portable Welder]

To: Fat Frank, sorry I took so long to respond, I typically use my cutting torch, a little water wont hurt a thing.
To: T Bone, When I fill a tank with water I try to keep my cut at the top of the tank which which allows any fumes that become available to be slowly burned off. I have to disagree with you about a few guys in heaven statement, if you use my method the only guys that are in heaven are the guys that had the tank roll over onto them. I am speaking from knowlege and experience, not out of a book.
I would have talked more about purging but the average guy trying to turn his 55 gal drum into a BBQ or the back yard mechanic- welder trying to braze up a leaky gas tank often times does'nt have a bottle of purging gas laying around but they do have a water hose.
I would strongly advise any one doing this be 100% positive that they under stand all the directions of doing something like this because as T- Bone was trying to explain doing this the wrong way can kill you.

[fyoung]

Guys here's link to a welding Cd with info on this and a bunch of other things..I'll leave it up for a few days sop feel free to download it. Hope this helps, Farris



here's the link

http://rectorenglish.0catch.com/users/fyoung/index.php

username : welding
password : arkansas

[Sbi1]

I tried a new tool today that worked well to cut a 120 gal. tank-an Evolution 230 circular saw. The tank was .270" thick and this saw did a nice job of cutting it. The hardest part was rolling the tank as I cut, but with a little help it wasn't too bad. This tank was cut to make a burn barrel to clean out the old files from our office, and I think we are going to make the short end into a grill (when we get time, of course ).

[fyoung]

sparks

I tried a new tool today that worked well to cut a 120 gal. tank-an Evolution 230 circular saw. The tank was .270" thick and this saw did a nice job of cutting it. The hardest part was rolling the tank as I cut, but with a little help it wasn't too bad. This tank was cut to make a burn barrel to clean out the old files from our office, and I think we are going to make the short end into a grill (when we get time, of course ).

saws cause sparks also so how did you prepare the tank before sawing?
Looks like you did a great job cutting thru it.
Thanks, Frris

[Sbi1]

I filled the tank completely full of water, dumped it out, and then checked it with a gas monitor (courtesy of the local fire dept.-I've been a member of the FD for 10 years, so I can get the gas monitor whenever I need it). After washing the tank out, it checked at 0% LEL, so it was safe to cut. It still stunk, though.

[Pyro]

Be careful cutting refrigerant tanks open because it's against the law (EPA)
They put a local man out of business for doing that..they fined the heck out of him and he fought it and spent a bunch of money and still lost. They said some of the tanks still had some in them and he was releasing it out into the air.
Hope this helps, Farris

Just so you know.... if the tank is light green then it is R-22 (white tanks are R-12) and there can be a fine imposed of up to $25,000.00 for the intensional release of the contents. so beware!

[bwilson]

Cutting open old tanks safely

Ive cut open 30 of the large ones - I took a variety of precautions - I remove all fittings and get rid of the propane but I needed to stop "wincing" when I worked on them. (Wincing means you harbor doubt as to the likelihood of blowing myself away)

My solution: Attached my plasma cutter to the tank with a braket and triggered it from a remote location. (as far as you need to feel protected).

Although I've never had one blow up I no longer "wince".

[mooseye]

Do not cut any sealed or even mostly closed tank with a torch!
There is a law against it in my state, especially drums or barrels.
The danger is not so much from the contents as from the unburned acetylene. Once enough has built up in the tank, and with the unused O2 from the blow hole you are forming a bomb.
A guy I worked with had 3 fingers gone as proof of this happening. He was cutting the top off a 55 gallon drum which had never had any flammable in it when it exploded. He is lucky to be alive!

The local bottled gas company has a shop where they use a lathe to cut the weld seam out. I would go with the purge with non flammable gas and reciprocating saw or some other none abrasive cutting device. You could remove the valve on a known empty tank, and drill a small escape hole in the other end for a good purge.

[weldr123]

propane tanks

I have cut many propane tanks open and prefer filling them up with water. This is a guaranteed safe way especially without access to a gas detection device.

[Morganic]

What do you fellas think about filling the tank with water and then letting it freeze?

I want to be able to work all around the tank cutting small holes and once I cut one all the water will drain.

The only problem I can think of is the ice expanding and fracturing the tank... but since it's fairly thick and the top valve is removed any expanding ice pressure would just come out of the top... yes no?

Oh, and I'm making a drum. Check 'em out at http://www.youtube.com/watch?v=bpMS15kJyOY

Morgan