SpudFiles

As the topic suggests, I recently acquired a small helium tank about the size of a gas grill propane tank at a "party" - they would've just thrown it away, so I got it for free. From what I can tell this thing is pretty thin, but the remaining helium shows up as 60 psi. It speceficially says not to re fill it, but I personally see no harm as long as I keep it at or below 100 PSI.

My question is: Is this thing safe to use? No ridiculously high pressures, just that 100 PSI, but the construction seems rather light. I realize that it still has a whole buncha helium left which could make it seem wimpier, but regardless, its kinda sketchy. Theres a welding seem around the circumference, and what seems like a welded shut hole on the top, so if something horrible happens theres a weak point so that it may split rather than frag.

I plan to use this thing for a small BBMG turret I'm making for use in airsoft, so the relatively small size is not much of a concern. I'd love to use this, so any feedback would be appreciated

Pictures would probably help a lot. Plus I want to see it

I have one of those too. I haven't got a design for it yet, but I reckon it would take around 300psi. I vaguely remember mine has a removable top, maybe, so I was thinking a mortar style cannon

Same one, 'cept mine's pink

I'm not using their crappy valve - I've teflon'ed and clamped on a hose leading to a gauge and quick-connect

At this point I feel quite comfortable with it, but would still like y'alls opinions

Mine is identical to yours, and yer 300psi should be fine, all metal construction, they probably just say don't refill because non professionals refilling could be bad. Any idea what pressure the helium starts at?

Even the thin aluminium fire extinguishers handle 300psi, so you should be fine with 100psi.

The valve internals would probably fail first anyway, so if you're not using the valve you'll be fine.

those helium tanks are made from the same exact material as propane tanks. I modified an old propane tank a while back for a science project and taken it up to 484psi before it started to leak. didn't get to find out exploding pressure because the compressor only went to 500psi.

So anything under 350psi, or even 400psi, should be golden

MrCrowley wrote:The valve internals would probably fail first anyway, so if you're not using the valve you'll be fine.

That is most likely why it only asks you to never refill, because the valve is only meant to let out air, not refill it with that valve.

I still use their gate valve (its welded on) but I abandoned that crappy balloon filler thing a long time ago. Thanks for the help then, I feel a lot safer now that 5 random people whom I met on the internet assure me that its safe , but honestly I appreciate it

if you are here( on the forum) then why are you worried about what the manufacture says "do not refill"

yea and pvc pipe manufacture's tell you how to build cannons out of their pipe..

if you question it then don't do it.....and don't be shock if/when something goes wrong

Zippster wrote:<image>

Same one, 'cept mine's pink

I'm not using their crappy valve - I've teflon'ed and clamped on a hose leading to a gauge and quick-connect

At this point I feel quite comfortable with it, but would still like y'alls opinions

Pink? Nice color for a cannon part

Telfon'ed? Why? Did you teflon the thing where you clamped the hose on?
Remember telfon does not seal, it lubes, meaning you can harder twist in threaded stuff. Do not teflon hose connectors, ever.

psycix wrote: Telfon'ed? Why? Did you teflon the thing where you clamped the hose on?
Remember telfon does not seal, it lubes, meaning you can harder twist in threaded stuff. Do not teflon hose connectors, ever.

I think he meant the threaded hose connectors, not a hose barb.

Yeah, the only part to clamp it on was a threaded piece which wasn't compatible with anything I could find, and no matter how hard I tried, it wouldnt seal. I figured the problem was air running straight up the threads, so to fix it I teflon'ed it up a lot and viola it sealed.

Oh ok then.
Good luck. Dont forget to show it to us when its in use