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Posted: 4/27/2002 3:16:15 PM EDT
A friend gave me a scuba tank, the valve has been taken off but other than that its in ok shape. I thought I might make a portable air tank out of it, pretty simple not alot of thought put into it. But in order to do this I think it might be a good idea to ask,What are most scuba tanks PSI rated at? Can you think of anything else to do with it?
Link Posted: 4/27/2002 3:23:23 PM EDT
Usually 80 PSI, but some are less. It should be marked, if it isn't, bring it to a scuba shop and have them test and stamp it. Its the only smart thing you can do with an unknown tank.
Link Posted: 4/27/2002 3:25:33 PM EDT
Originally Posted By Minman72: Usually 80 PSI, but some are less. It should be marked, if it isn't, bring it to a scuba shop and have them test and stamp it. Its the only smart thing you can do with an unknown tank.
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That's the correct answer. Those tanks are only rated for a certain period of time and then the scuba shops won't touch them. Bring it to them and they'll have the info on it.
Link Posted: 4/27/2002 3:29:20 PM EDT
Most scuba tanks will hold around 3000psi. I imagine that the tank you have didn't pass the hydrostatic or visual test and was condemned. Check the dates around the neck of the tank, this will give you a good idea when the tank is/was good to. I THINK that it would be safe to use as an air can type set up as the ability to get much more than 125-200psi out of a common compressor is unlikely.
Link Posted: 4/27/2002 3:29:20 PM EDT
Most scuba tanks are 80 cubic feet, about the amount of air in a phone booth. They are usually rated around 4000 psi, with a normal scuba fill of 3000 to 3200 psi. They can be re-certified by hydro and visual check for around $25. Some off roaders use them as air tanks with the right regulators.
Link Posted: 4/27/2002 3:31:49 PM EDT
Texasshark is correct.
Link Posted: 4/27/2002 3:32:53 PM EDT
Actually, an aluminum tank is rated to 3000psi working pressure, and tested to much higher. Its not unusual to see them at 3300psi on a warm day. Not sure what the 80 psi thing is about- my home compressor runs at 125... Anyway, the hydrostatic test is required every 5 years and must be current prior to filling. Steel tanks rate at a lower pressure- and the composite tanks can hold up to 4500psi depending on the application. [8D]
Link Posted: 4/27/2002 3:45:20 PM EDT
Scuba tanks are made of either steel or aluminum and come in a wide range of sizes. The two most common sizes are steel tanks rated at 2250 psi, which hold approx. 72 cu.ft. of air and aluminum tanks rated at 3000 psi which hold approx. 80 cu. ft. of air. All tanks are stamped at the top with there maximum pressure rating. Scuba tanks must be pressure tested every 5 years. There will also be one or more date stamps at the top showing when it was tested. You can buy a used valve for around $15.00. You should take it to a scuba shop to have it checked out. They can tell you exactly what you have.
Link Posted: 4/27/2002 4:44:20 PM EDT
Our SCBA tanks that I use at work are the new SCOTT composite tanks and are normally charged to around 3000psi. They have a much shorter life span than the steel tanks, but are great to use because they are [b]so[/b] much lighter. They are rated for 4500psi and are the 60 minute tanks. The down side is that they cost over $2K each.
Link Posted: 4/27/2002 4:56:43 PM EDT
This tank is steel. I cannot find any date stamp. There is a stamp on it actually two lines but nothing I can make out to be date. I had planned on putting a appropriate valve and pressure gage on it and filling it at a gas station. Can a scuba shop test the tank without the valve on it?
Link Posted: 4/27/2002 5:00:06 PM EDT
Link Posted: 4/27/2002 5:18:33 PM EDT
Link Posted: 4/27/2002 5:44:31 PM EDT
You have gotten some excellent info in your replies! Do take the time to get it hydro tested. Not that you will ever be close to the max, IF there is a weakness and the tank was hot it could go off and look like a missle. I have seen two cars that had tanks in the trunk-one 80 cu/ft aluminum and a 72 cu/ft steel. They were torn up very badly. You can get a regulator and carry high pressure in you tank and step it down to your needed level. That way you will have much more in terms of volume and less need to stop and refill. Just a thought.
Link Posted: 4/27/2002 5:54:53 PM EDT
Originally Posted By brouhaha: Fill it up to 3000psi and take it to the range for some target practice [:D] Just be careul...you never know where it'll rocket off to.
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or where the reflected round will go.. ;)
Link Posted: 4/27/2002 6:07:21 PM EDT
Heres what you do.Get the tank hydroed and ask a shop for a used valve if possible.Then buy a first stage reg (used if possible)explain that you want an air tank.Then you can get a hose for that regulator which knocks the pressure to alot lower than 2250.you can buy an air thing that goes to your air tools at a scuba shop that connects to a buoyancy control air hose. I dive and found the nipple for the air tools at a dive shop i bought it so i can put it on a tire inflator to go to the dunes when i have to air down.Mow all i do now is get my regs out hook up the inflator and air up my tires.there is alot of air inthe tank can easily air up 4 33x12 tires from 5psi to 35 and have plenty left.The only thing for me is that i have my dive computer and regs all hooked up.but i will be buying a seperate first stage and a 6' hose just for an air tank only.
Link Posted: 4/27/2002 6:10:21 PM EDT
Link Posted: 4/27/2002 9:08:06 PM EDT
What are the numbers on the tank?
Link Posted: 4/28/2002 1:33:55 PM EDT
Jeez, I can't believe I mixed up PSI and Cubic Ft! Just make sure you have it tested at a shop to play it safe.
Link Posted: 4/28/2002 1:55:36 PM EDT
Weren't there some problems with tanks made from 6351 T-6 alloy?
Link Posted: 5/1/2002 5:34:08 PM EDT
These are the numbers off the tank ,First line OT-3AA1800,Second line 27305DK ,Last Line AWK.I hope these may help.
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