CO2 tank relief valve

[backhousebrew]

The pressure relief valve on my 5lb aluminum tank popped open!
This happened yesterday at an outdoor party in Ontario. Temperature was around 85
The tank was filled in the morning at California Welding Supply in Santa Ana. $15
The tank wasn't hooked up to the keg yet. The valve was closed.
Suddenly,...boom!!! The ice cold gas came shooting out with the sound of a locomotive going by.
I was standing right next to it and I knew the valve was closed so all I could do was stand there and watch the full tank of gas drift away in the wind.
It seems that the PRV should have closed after releasing some of the pressure. It's either a bad valve or maybe it froze open from the CO2.
Lesson learned: If the tank is full, keep it from getting hot or be sure to relieve some pressure periodically.

[CurtisG]

That's crazy. Glad no one was hurt.

-Curtis

[backyard brewer]

Tanks don't have an OPD per se. They have a 'burst disc' which is a one-shot deal designed to quickly empty the tank if the pressure exceeds the tank limit. Much simpler, no moving parts or springs to fail. If the tank was just filled and in warm weather, it could easily exceed the pressure, especially if they over-filled it. If it was in the sun, it's almost a guarantee.

If you're ever storing CO2 tanks in a warm place like a garage, it's not a bad idea to know the tare weight of your cylinder and check how much CO2 you got after a fill. If it's over filled (by weight) then vent a little. Just weigh the full tank and subtract the tare. NEVER leave freshly filled tanks in a car!

Don: Let them know the burst disc ruptured and they should be able to put a new one on right away, it just threads into the tank valve.

Also glad no one was hurt.

[backhousebrew]

Thanks for the info BB
I took it back and told them what happened.
They installed a new burst disc and refilled the tank - no charge