C02 tank sudden pressure loss. PRV?

Barring a catastrophic failure, there are only three orifices that gas can leak from: master valve thread (where it mates to tank), master needle valve (the knob you turn), and prv. You'll probably have to fill it (partially) again to find the culprit. It absolutely can leak with no reg attached if some fool left the valve cracked open. But from your description (icicles) it sounds more like a prv failed and released gas very quickly. How hot was it parked in the shade?

 

Sounds like the prv crapped out to me. Icicles and frost would point toward a sudden complete loss of gas. Glad it didn't happen while you were driving.

 

I would just exchange it for another filled bottle (what I do with propane also when my bottle inspection is past due).

 

I've never owned my own tank. I use it till it's empty then go to the welding supply store and swap it out for a fresh one of beverage grade CO2.
I would take your tank to a local welding supply store and see if they can fix it.
It's not a repair I would attempt because a full tank pressure is in the thousands of psi and doing something wrong might get dangerous.

 

One time I had a CO2 tank fall over and opened the knob. luckily I did not have the tunes cranked and heard it!

 

Take it back to the guy who filled it and tell him what happened. He may try to make it right, particularly if it turns out to have been on oversight on his part - he missed a leaky thread, for example. That said, a LHBS probably has little control over that, so don't get your hopes too high.

 

This was my first thought. Sounds like something failed. Find an air supply company and swap it out. The one I use ONLY does swaps, not fills, though I'll occasionly use a liquor store that does fills.

 

I'm pretty sure I've never filled. Was a little sad to swap out my brand new tank but it works great and who cares what it really looks like...

 

Not necessarily . . . the prv is made to be replaced. If that is the problem it is relatively simple to remove/replace. Except prv's are not a mainstream item, usually sold in wholesale lots. If you have a fire extinguisher refill store nearby they will have some laying around. They should also have complete CGA-320 valves laying around. These guys wholesale for about 10 bucks and retail for 25'ish. Don't be afraid to buy a used valve.

You didn't ask, but if you have a fire extinguisher shop around it would be a good time to upgrade to a 20 lb tank . . . you will save money. Most posters on this Forum advocate swapping-out tanks . . . I swing both ways, just depending on my mood and what's available.

 

Regarding 5 lb vs 20 lb tanks, one of the suppliers in my area charges the same price for both. Hard to justify 5 lbs in that case. Those who charge per lb are generally no more than a few dollars difference between 5 and 20 - still hard to justify the smaller tank. The major component of the price is 'setup', which is the same no matter what size tank they're filling. Even ignoring the price, 20 lbs is just so much more convenient than 5. I get mine filled once every 2 to 2 1/2 years. It would be more like every 5 to 6 months with a 5 lb tank. I keep a spare on hand - also 20 lbs - so I'm virtually never out of gas.

 

Life is too short...OP: give up your shiny new tank and exchange it for something ugly

 

Suppose this answers why when I took a 5 lb tank to swap out, and all they had was 20 lb tanks left, they just gave me the 20 lb tank for the same price.

 

Prices are all over the map around here, so it's hard to say what is 'normal', though $31 does seem to be pushing it on the high side for 5#. Does the guy who fills it for 9 or 10 bucks also do swaps?

 

Not to go off on a tangent, but this thread illustrates one of the few downsides to a bigger tank. If you have a 5 lb tank, the limit of your loss to a leak is 5 lbs of gas while, with a 20 lb tank, it's 4x that amount. Long term, though, you're still economically way ahead with a bigger tank, since you will have learned your lesson on the first leak ...presumably.

 

If what I am hearing is true though filling or swapping a 5 versus 20 lb tank is negligible so its not 4X the loss.

 

Accountant or Engineer or both? Maybe more icicles is the only downside . . . and in Florida that'd be refreshing: