Reusing a Disposable Helium Tank





Introduction: Reusing a Disposable Helium Tank

I had a couple helium tanks leftover from the kids' birthday parties, so I figured I'd take a whack at reusing them. Here's how to attach 1/4" OD tubing to one. From there, you can use it to store compressed gases (e.g. CO2, air).

Disposable helium tank (the ones I have are Balloon Time)
1/4" OD compression nut with insert
1/4" OD tubing
3/16" drill bit
5/16" drill bit
cutoff wheel
Teflon tape

Disclaimer:Author is not responsible for loss of life, limb or property. Author is not responsible for anything. In fact, author is completely irresponsible. I mean, you should see some of the stuff he gets up to. It's amazing he hasn't burned the house down yet. Don't listen to him. Seriously.

Step 1: Cutting

Remove the nozzle. Cut the connector off as close to the thread as possible. There should be a small plastic nib inside. Remove that.

Step 2: Drilling

Drill out the valve with a 3/16" bit. A bunch of black plastic will come out. Keep drilling until it bottoms out. As far as I can tell, the plastic is a check valve that prevents refilling.

Countersink with a 5/16" bit to a depth of about 1/4".

Wrap with Teflon tape, overlapping the edge.

Step 3: Attaching the Tubing

Assemble the compression nut and attach to the connector. It just happens to be the same thread.

I've tested this up to 70 psi. Not sure how far it'll go.

I've done this with two tanks so far. On one, the valve doesn't close all the way anymore, so I put an inline valve on the tubing instead. The other one seems to work fine.

I'm currently using one for compressed CO2. Haven't decided what to do with the other yet.



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    I will say this as politely as possible. I am so thankful that the Wright Bros, Newcomen, Watts, Fulton, and every pioneer of science and industry did not share your cowardice. Yes, cowardice to match your contempt for objective critical thinking that goes beyond reading a warning label.

    Mods, please do not kick this post, I promise the nicest thing a person can do is help another overcome their own ignorance. I promise you, everything I am saying here is true and it comes from a place of love.

    Now... About these tanks. Compared to a normal helium tank hese are low pressure tanks. Helium tanks are normally like 3000psi and shaped like O2 tanks. Those H2 tanks hold liquid H2 and a lot of it.

    These little pink piggy tanks hold gasseous H2, enough to fill 40 or so balloons. The pressure of the H2 in the tank is about 260PSI and the tanks are rated to function at over 300PSI.

    These helium tanks are identical to the white refrigerant tanks. Tanks for which they sell an addapter to convert it to a compressed air storage tank (

    The valve regulator on the helium tank even matched this conversion kit.

    You know what a steel tank at 60PSI does when it ruptures? Not a whole lot. It hisses and whistles and maybe it wonders who shot it because that's the only way it's going to rupture.

    Jesus... this is what the end of our species looks like. We go out, not with a bang, but with a "don't try anything new, you might hurt yourself!"

    just a couple, hopefully constructive comments I'd like to make in response to your post. First point is that the symbol for helium is "He" not "H". The second critical point is that no cylinder of helium gas contains liquid helium. While it is true that some tanks of gas do largely contain a liquid with a gas phase, examples being CO2 and N2O, none of the gases like oxygen, nitrogen, hydrogen and or helium are at sufficiently high pressure to exist as a liquid at room temperature.

    Comments like you made are likely well intentioned, but that doesn't make them correct. A metal tank that ruptures, even if pressurized initially to only 60psi can, under certain circumstances behave like a bomb. Knocking a tank valve off a pressurized tank is a much less violent event than is a tank rupture. The problem is that these tanks are not designed to be re pressurized. That doesn't mean they can't be represurized but they may not behave predictably.

    A very real senario that results in a tragedy is a tank that is pressured to 100psi at night when the ambient temperature is cool. Let's say the temperature during the day doubles as compared to temperature at filling. The tank pressure will double. This assumes you only have dry air in the tank. Add a volatile liquid and the situation becomes even worse (ie CO2 or nitrous oxide -N2O).

    The reason tanks are certified and tested "hydrostatically" is because water is essentially incompressible. A water filled tank at 3000psi will behave much more predictably at failure than a tank failing with 300psi of air.

    Tanks can be repurposed safely and are repurposed by people all the time BUT, if one fails, the full weight of the law will come down on you. Make no mistake about that. It says "DO NOT REFILL" not only to protect you, but also to put the legal liability squarely on your shoulders, should something go wrong. You could pay (as in cash money) for this for the rest of your life, if your negligence harms someone other than your self.


    When calculating pressure increase in relationship to temp we convert to kelvin not Fahrenheit. Doubling temperature from 30 to 60 deg Fahrenheit is only a 5.8% increase when converted to Kelvin. So, your pressure increase would only be 5.8% not double. A 100psi tank stored in a place that goes from 30deg F to 60F would be raised to approx 106psi... which is why it is safe to keep tires on your car(they won't explode when the temp doubles in deg F) or an air storage tank in your garage where ambient temps are very unstable.

    "A very real senario that results in a tragedy is a tank that is
    pressured to 100psi at night when the ambient temperature is cool.
    Let's say the temperature during the day doubles as compared to
    temperature at filling. The tank pressure will double."

    Wow, that's scary! You are hereby cordially invited to prove that statement. I never realized that when my shop air compressor cycles at 10PM just before I shut it off for the night, I am risking having it explode at noon the next day.

    Of course, I also didn't realize that 60 degrees Fahrenheit is double the temperature as 30 degrees F.

    not sure if the possum is still alive or not but on the chance he is, I'll try and clarify some points

    First, the compressor does not have to cycle at night for a problem to occur. If the tank is at 100psi with an ambient (read that as air temperature) temp of 35 F (ie just above freezing in the desert night air), AND you don't have a pressure relief valve on the system (or the relief valve doesn't properly work), the pressure WILL go up in the morning, as the daily temperature goes up. This isn't my opinion and certainly doesn't need "proof". Pressure varies directly as the temperature so..... If the temperature doubles, the pressure will double (assuming the volume doesn't change). If the pressure doesn't go up, the volume MUST increase. The only way the helium tank can increase its volume is by expanding. Once it expands to the point that the weakest part of the tank fails, the tank RUPTURES.

    As far as your last question, "I didn't realize that 60 degrees F was double 30 degrees F", I can only suggest you speak with an adult about that one. Another way to think of it is in terms of money. If you have $30 today and someone gives you $30 more, you have "doubled your money". Does that clarify things?

    Bottom line is, read about Gas Laws. Don't worry about ideal vs real gas behaviour. (P1V1)/T1=(P2V2)/T2 is a pretty good place to start.


    As SippingD pointed out, 60 degrees F is NOT double the temperature of 30 degrees F. And that was an observation btw; not a question.

    Also, I never said the pressure will not increase in the tank of my air compressor when the sun comes up. Just that it won't double, nor increase to anything approaching an unsafe level.

    en2oh - You got the equation right, but you are using the wrong temperature scale. You need to use absolute temperatures (Kelvin) for those equations to work. 30F is 272K and 60F is 288K. So, with a temperature increase from 30F to 60F the pressure will increase less than 6%.

    yup, you're correct ;)

    The problem with this debate is not about safe vs risky. It's really about factoring in the imponderables. When you have too many uncontrolled variables, the risk for most becomes unacceptable. A thick walled pressure vessel will tolerate (safely) repeated pressure / depressurization cycles with little risk (hence the need to recertify scuba tanks on a schedule rather than simply saying "pass once, good for life" or, "only good for 5 years") of harm to the user or the public.

    A thin walled vessel is quite a different story. I don't think anyone is saying "you can't do this", but more than a few have suggested that some of the risks associated with this practice might not have been considered by the original poster.

    Your observation about the dimensions of this equation are correct, but the practical issue remains. A marginal pressure vessel that is safely charged to its working limits may, under very real life circumstances fail due to something as simple as an unexpected rise in temperature.

    Even these helium tanks may fail under circumstances that are totally within the design parameters. But if they do, there is a company with deep pockets at the end of the street that a victim or their next of kin may turn to.

    Talk about going out with a bang. Filling balloons at a party with hydrogen is probably not a good idea. ;)

    what is funny is that i disagree with that as well, if you fill the balloons with pure hydrogen the explosion is much softer (no bang all woosh), pretty fun for kids to watch; even better for parties ;)