What is the recommended maximum pressure for an oxygen tank?

I am curious what the maximum working pressure of a oxygen cylinder would be? Searching the internet I am not coming up with much information. Looking at the tanks here, the regulator reads up to 4000 PSI. The rupture disk on the valve has "3775" stamped on it which I am assuming is 3775 PSI. That is on a "300" size tank. Trying to find out if I would be okay at 3200 PSI or less.

I'm not sure of the maximum, but if you tip one over and knock off the valve, they will go through a cement block wall. Lot of pressure.

Eric, Look up "Charles gas laws" or "Boyles gas laws". I think you will find at a certain pressure it turns liquid and will not raise the pressure unless you confine the chamber and it fills to capacity with liquid. That would not be good. What are you making?

I think the idea here was to keep it contained in safe manner. It may very well depend on the material the tank is constructed of, if not mistaken there are some Al tanks out there, but I may be think 'in scuba not shop use. Little research and it would seem a size 300 tank would have a max pressure of 2640 PSI, which is roughly 337 cubic feet. Data came from a pamphlet passed out by Air-Gas I received while I was in school.

Tom, That is exactly what I was alluding to, As far as the tanks the other men have been speaking of... I don't believe they are realizing what Eric is asking. A scuba tank surely is not 337 cubic feet. The K tank which is used by welding shops and junk yards is typically 270 cubic feet, it is constructed of 3/8 inch wall tube and hammer forged on the end to make the threaded portion. This tank is 3 times the physical size of "scuba tanks". I cannot remember the "type" of tank Eric is talking about but the 300 cubic foot tank is about 66 inches tall and you would not want to take that on a dive... Unless you are Davy Jones. I know that when I get my tanks refilled the most I ever received was 2500 lbs of gage pressure, most of the time it registers in at 2300 lbs. Now I know when I watch them fill the tank it goes in under "Liquid" not gas... If so it would take an immense amount of time to fill one. And the operator tells me that he weighs in the charge by the cubic foot of the tank. So if he has a 66 inch tall tank it is so much liquid as opposed to the 24 inch scuba tanks... Still the "true gas" responds to pressure and temperature. Mick

Hawk, I was not saying anything about aluminum tanks not being of that size. I believe that they are used in the medical field more often for weight (wheelchairs, people lugging them). I apologize that you are misconstruing what I was asking the op. OPSIMC: I was answering someone else s statement about the "true gas" . Their words! I understand how gas vs pressure works very well. I may not be able to put it into words very well. If I remember correctly oxygen turns into liquid (boils) at right around -300 F. I am aware of the Oxygen is not liquid in the cylinder, But they put a predetermined charge into the tank (hence they want to know what size tank you are filling). While acetylene and alot of the methanes are in fact liquid in the tanks. That is why propane, and acetylene gauges read 200 lbs the entire time until the last drop of liquid boils off and the pressure diminishes. Have a Merry Christmas everyone!

My refills have generally clocked 3000psi

The answer is, it depends on the cylinder construction. Cylinders are built from Steel, Aluminum, composit and even Titanium. High pressure cylinders can range anywhere from around 1800psi up to around 4000 psi and I have even seen large special cylinders at 10,000 psi. The service pressure is generally stamped on the neck of the cylinder with the serial number, manufacturing codes, and in the US a DOT specification. I have seen cylinders at 1800, 2200, 2250, 3000, 3442 and I am sure there are others. Other than special cleaning to remove all traces of any organic contamination oxygen cylinders are not different that other cylinders. High pressure O2 does not play well with any oil or organic material. Never use any kind of oil lube on O2 fittings that is not designed for oxygen service. Generally all cylinders must be hydrostat tested on a regular basis, the time interval determined by the manufacturer and the DOT code on the cylinder. For a steel DOT-3AA 2015 psi steel cylinder 5 years is standard, some are capable of every 10 years if marked. I don't know about aluminum. I think composite cylinders are the only ones with a service life (15years). Craig

Excellent information Craig, thank you!

I used to get high pressure nitrogen tanks for re-filling accumulators on diecasters. I believe they came at about 5000 psi. Looked like a standard tank from the outside. If you need the higher pressure one of these may be the way to go to have a little wiggle room.
Joe

The working pressure is stamped on the shoulder of the tank. Most oxygen tanks are 2215 psi. Here is how to read the info stamped on the tanks. Markings on tank: DOT 3A 2015 3{*}68+ DOT stands for Department of Transportation. Older tanks will have ICC which is Interstate Commerce Commission. The name has since been changed to DOT.Tanks filled in the US MUST have this. Most tanks from overseas don't have this and can't be filled in the US. Some tanks also have CTC which is Transport Canada. 3A means it's a steel tank. Lots of tanks have a 3AA which also means steel. Aluminum tanks are stamped 3AL. 2015 is the working pressure of the tank. This is the maximum pressure the tank can be filled to AT 70 DEGREES. 3*78+ This is the date of the original hydro. The 3 is the month. The {*} will be a symbol which identifies the hydro tester. The 68 is the year. The + means the tank can be filled to 10% over the marked working pressure. This was done on steel tanks because of the shortage of steel during WW2. If it is marked with a star, that means it only has to be hydrotested every 10 years instead of every 5 AS LONG AS it has met certain restrictions like being removed from the bank every time it's refilled, ect. There are also tanks with other markings like E 10095 or SP 8659 which are special exemptions granted by the DOT and carry special restrictions on what can be put in them, how they can be used and how they must be hydrotested.