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View Full Version : Tanks for OxyAcetylene welding.



pgmrdan
09-24-2003, 09:46 AM
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[This message has been edited by pgmrdan (edited 03-19-2004).]

JCHannum
09-24-2003, 10:36 AM
I don't know about that. I just went to the dealer, bought the tanks, and trade them in each time for filled tanks.
If I move, or want to get out of welding, I sell them back to that dealer. (Or another that deals in that brand of gas, Airco in this case.)
The trade in value today is more than I paid for them 12 or 13 years ago, and I don't need to worry about reinspection, lease or rental fees and so forth.

pgmrdan
09-24-2003, 10:57 AM
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[This message has been edited by pgmrdan (edited 03-08-2004).]

JCHannum
09-24-2003, 11:11 AM
It's called inflation.

pgmrdan
09-24-2003, 11:56 AM
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[This message has been edited by pgmrdan (edited 03-08-2004).]

ibewgypsie
09-24-2003, 11:58 AM
I have my tanks through a local supply, $50 per tank per year x argon tanks, x acetylene tanks, x oxygen tanks, x trimix tanks, x propane forge tank.... Yeah a lot of rental fees...

I am interested in the security deposit ideal...

I think I had a deal before $150 for 5 years for the ox-acet tanks.

You can purchase the small tanks. They are always empty around here. Easiest to use?

David.....

[This message has been edited by ibewgypsie (edited 09-24-2003).]

pgmrdan
09-24-2003, 12:26 PM
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[This message has been edited by pgmrdan (edited 03-08-2004).]

JCHannum
09-24-2003, 12:57 PM
They buy them back for 75 or 80 percent of current price which is more than 100 percent of what I paid for them that long ago.
Check with your supplier, there are different adaptors for oxygen & acetylene tanks. Most suppliers will provide an adaptor to fit your regulators, usually at no cost.

pgmrdan
09-24-2003, 01:08 PM
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[This message has been edited by pgmrdan (edited 03-08-2004).]

brunneng
09-24-2003, 06:34 PM
Guess I got real lucky. The previous owner of my sisters property left behind a set of large oxy/ac tanks and after several years of never turning back up they became mine.

I had them tested and filled. I actually had to trade down the ac tank because it was so big it wouldn't fit the trolley next to the oxy tank.

Probably why they weren't on a trolley to start with.

CCWKen
09-25-2003, 01:19 AM
I just buy my tanks. When you take them in to refill, you get a "tested" tank back. I just got a 122cu.ft. Argon tank a few months back. Filled, it was right around $190. (TTL-out the door).
If I ever want to sell it, I'll get the Then Prevailing Rate. $200 sounds good already! Also, I'm not restricted to where I can have it refilled (exchanged). If one place is out of my size, I can go to another. The last time I check on a lease, you had to take it back to that company.

Thrud
09-25-2003, 02:06 AM
The other advantage to trading tanks in every time is you get a bottle that is tested and certified every time.

Also, I would not buy the larger C2H2 tank - you use way more oxygen up anyway (1:2.5+).

pgmrdan
09-25-2003, 09:32 AM
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[This message has been edited by pgmrdan (edited 03-08-2004).]

docsteve66
09-25-2003, 01:18 PM
PGm: you ask"At about what size do these tanks become more stationary than portable?"

In my experience limited to having lived only one life- it is very much a function of age. I traded larger tanks for smaller when the dolly and tanks became too hard to get over bumps. Should have put bigger wheels on the truck. http://bbs.homeshopmachinist.net//smile.gif

pgmrdan
09-25-2003, 03:30 PM
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[This message has been edited by pgmrdan (edited 03-08-2004).]

docsteve66
09-25-2003, 09:39 PM
after you do a job in the sun or cold they gonna look real HEAVY!!!! http://bbs.homeshopmachinist.net//smile.gif

Been there ...etc

Thrud
09-26-2003, 01:51 AM
Dan

With the 30 or 40 Cu. Ft.(plumber sized) Acetylene tank and 80 or 120 is just about right (get both filled at the same time). A 100Lb. Propane tank and 80^3' requires 3 or 4 Oxygen tanks per propane tank. I prefer the smaller porta-paks myself because of oldfartitus - I don't need O/A or O/H that often - use MAPP and propane mostly.

Evan
09-26-2003, 02:01 AM
BTW,

As to why Thrud said you will use 1 actylene to 2.5 oxygen; When gas welding the mixture ratio is about 1 to 1. BUT, when cutting you have the preheat flame at 1 to 1 and then the oxy jet to do the actual cutting. It depends on how much cutting you will do but a ratio of at least 1 acetylene to 2 or 2.5 oxy is about right. What this means is that if you want your tanks to last about the same amount of time between fills the oxy should be at least twice the cubic feet of the acetylene. Never mind the pressure of the tanks, the acetylene is dissolved in acetone and comes out of solution as it is used. You can't compare the tank pressures.

pgmrdan
09-26-2003, 05:45 PM
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[This message has been edited by pgmrdan (edited 03-19-2004).]

Thrud
09-26-2003, 05:58 PM
Dan

What I meant by 1:2.5 is for complete combustion, 1 mole of C2H2 requires 2.5 moles of O2 at STP (Standard temperature & pressure - 1 bar @ 20*C). A rich flame requires less O2, while an oxydizing flame uses much more (id est while cutting) Oxygen. Sorry for the poor articulation.

Evan
09-26-2003, 06:29 PM
I did a bit of research on it and found that acetylene/oxygen can be used at ratios from 1 to 1 up to 1 to 2.5, measured by volume, as Thrud explained. The situation changes dramatically with propane. It runs at ratios of from 1 propane to 3.5 oxy up to 1 to 5. Meaning, propane is going to use a lot more oxy. Might be a bit of false economy. Cutting just increases the oxy use further.

pgmrdan
09-26-2003, 06:33 PM
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[This message has been edited by pgmrdan (edited 03-08-2004).]

Evan
09-26-2003, 06:38 PM
That sounds right.

pgmrdan
09-26-2003, 06:59 PM
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[This message has been edited by pgmrdan (edited 03-08-2004).]

Evan
09-26-2003, 07:30 PM
You will have CO if the flame is set fuel rich.

pgmrdan
09-26-2003, 08:14 PM
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[This message has been edited by pgmrdan (edited 03-08-2004).]

CCWKen
09-26-2003, 10:59 PM
Geez, all this alphabet soup is making me hungry. I'm out in the sticks and the nearest welding gas distributor is about 15 miles away (30 round-trip). I went with the largest tanks I thought I'd need and could still move around the shop.
I went with 80 on the C2H2 and 120 and up on all the rest (4). All of them are on carts so it's no big deal to move them.