Converting Oxygen Cylinder

[boyntonstu]

This is a converted 66 cu in M6 Aluminum cylinder.

It weighs about 2 pounds.

It was a challenge to tap a 1/2" pipe thread into it.

I twisted the cylinder with a homemade strap wrench while the tap was held fixed in a vice.

No drilling, just forced it through the existing threads.

It took about 20 cycles of in out turning to get it done.

A 1/2" > 1/4" bushing and it was finished.

I can pump it up to 700 psi in 80 seconds.

No leaks.

The Trom-Boyn chamber uses 50 psi per shot.

It is a 6 shooter to 400 psi.

I haven't maxed out the compressor because I am afraid of messing up a good thing.

[Gun Freak]

Looks really nice. The rating was somewhere around 2500 psi right?

[boyntonstu]

Looks really nice. The rating was somewhere around 2500 psi right?

2200 psi rating.

I found the tank in trash will some oxygen in it.

[Gun Freak]

Lucky... That'll make a nice tank.

[theBOOM]

Is that a brass tee your using there for the fittings???
I know for a fact that those are rated to only 150 psi, beware.

Other than that, AWESOME tank, do you think I could do the same with a fire extinguisher I have, it's like a 3 or 4 gallon fire extinguisher, and I'm pretty sure it can hold atleast 300 psi.

[Gun Freak]

Is that a brass tee your using there for the fittings???
I know for a fact that those are rated to only 150 psi, beware.

I read somewhere that brass fittings were rated to 1200, but maybe those are the other types. The fittings Stu is using have been used on a few HP guns that I have seen.

[boyntonstu]

Is that a brass tee your using there for the fittings???
I know for a fact that those are rated to only 150 psi, beware.

Other than that, AWESOME tank, do you think I could do the same with a fire extinguisher I have, it's like a 3 or 4 gallon fire extinguisher, and I'm pretty sure it can hold atleast 300 psi.

You are correct about the ratings of brass fittings, etc.

I can't imagine their failure at any fridge compressor pressure.

The aluminum quick connects are weaker than solid brass and I use them and ball valves at 600 psi all the time.

Rating psi and burst psi are not the same.

Compare type L copper tubing to the brass T and see which is capable of higher pressure.

[theBOOM]

Well, I'm just saying, it's not a wise decision to exceed a fitting's pressure rating by 4, so just a word of warning.
Kinda off topic but after doign a search, I figuired that Dry chemical fire extingiushers can hold up 250 or 300 psi just fine right??

Edit, for a piece of mind I would swap out that brass fittings for galvanized steel 1/4" fittings, I would trust it more at these pressures. Just my opinion though.

[Technician1002]

Dry chem extinguishers have a working pressure of 150 PSI. I don't know the burst pressure or hydrostatic test pressure.

I would not recommend using the test pressure as a working pressure. Think pneumatic bomb. Fire extinguishers are designed to hold a static pressure, not work up and down. Repeated applications of hydrostatic pressure but using air is highly not recommended. A failure could be lethal.

Edit; Google is your friend.

There are two types of hydrostatic test stickers (Photo 6) that you may see: 1) non- DOT cylinder, three times the gauge pressure or to the manufacturer’s recommendation on the label, the pressure, year, and month the test was performed, 2) DOT cylinder, which displays a “RIN” retested identification number sticker, the cylinder tested to twice the gauge pressure or to the manufacturer’s recommendation, month and year the test was performed. All test information will be on the label.

Edit, for a piece of mind I would swap out that brass fittings for galvanized steel 1/4" fittings, I would trust it more at these pressures. Just my opinion though.

May I recommend hydraulic oil fittings?

[theBOOM]

Thanks tech for the info, I guess I'll still use it at 150 psi, it's pretty big so it'll give me alot of refills for anything I need...

I don't think he needs to buy hydrauilic fittings, they're pretty pricey, normal galvanized 1/4" fittings will do, they're rated high enough for anything a fridgey can do.

[jackssmirkingrevenge]

Sounds like a good excuse to make a semi-automatic

[spudamine]

don't think he needs to buy hydrauilic fittings, they're pretty pricey, normal galvanized 1/4" fittings will do, they're rated high enough for anything a fridgey can do.

Could you show me a link to such galvanised fittings? I've never seen any rated to over 150psi. Mind you most pneumatic fittings are only rated to 150psi, because that's what they're going to be used at and why would the manufacturer bother rating them higher? An exception I've found is stainless steel fittings for steam use but they're still generally only rated to 300 for dry air.
personally I've always gone for brass over cheap galvanised fittings, the quality of the manufacturing looks better, looking at the thickness of the metal at this size both should easily hold 600psi.

[cannon monkey]

i got 4 tanks bout same 1900 psi rating and a big one with 3200 rating i picked up from my mom's work looking to make something big with them one day

[theBOOM]

Spudamine, I used the wrong words, they don't actually say "rated to 600 psi" but from tests members of this site have made, I can assure you that 1/4" galv. fittings can hold 600 psi safely.

http://www.spudfiles.com/forums/me20h-4 ... 14452.html

I'm sure that creates more pressure than fridge compressors
They wheren't even 1/4", yes brass might look shiny and cool but I trust galvanized more when it comes to pressure. Oh, and they have them in my ace hardware store along with some zinc plated fittings too.

[Crna Legija]

i have a FE that i use as a tank it was full of powder so im gessing its dry chem. it has threads that are close to 1/2 inch bsp but not perfect i just got my brother to weld a pipe nipple in to the end. i have use it to 300psi 10 times a day for 3 months now no problems