Consensus on Overfilling Tanks?

[PfcAJ]

I heard/understood wrong.

So given that LP steels are (typically?) overfilled in cave country, is there anything done to mitigate any risk?

Vip and hydro.

I’ve been around overfilled steels for 15 years and I’ve yet to hear of a steel tank that’s in hydro/ vip failing.

 

[rjack321]

I heard/understood wrong.

So given that LP steels are (typically?) overfilled in cave country, is there anything done to mitigate any risk?

what risk are you talking about?

doubling up the burst disks or replacing them with stainless steel disks would be the only thing I can think of? And not using the 4000psi disks ever even if you just use the valves normally

 

[rjack321]

I don't.

Okay for the cave country divers, and I'm asking this purely out of curiosity, have there been incidents that you all know of? Not ones that make the media, as so many scuba incidents in general get buried. If there has been incidents from overfilling LP cylinders, what, if anything, is done as a practice to reduce reoccurrences?

None for steel tanks except for some severely corroded lp72s - and they may not have even been overfilled

 

[rddvet]

Doesn't the cave community address overfills by rebuilding the valves religiously every X amount of time.

@rjack321, is that correct?

I think what you're thinking about is that most shops in cave country recommend you rebuild your valves every 5 years at the time of hydro. It has nothing to do with overfilling. It's because the most convenient time to rebuild valves is when they're being pulled apart for hydro. It's definitely not necessary, but I think a good rule of thumb to follow. It is nowhere near a universal truth in cave country at all and I know alot of people who only rebuild their valves when they fail.

I still don't understand people's fear of overfilling tanks. You pretty much never hear of an overfilled set of doubles exploding. Now an oxygen bottle filled to 3000 psi or more and not being properly secured is another story.

 

[wetb4igetinthewater]

what risk are you talking about?

Primarily burst disk failure: Burst discs: Yes they burst when they shouldn't.

doubling up the burst disks or replacing them with stainless steel disks would be the only thing I can think of? And not using the 4000psi disks ever even if you just use the valves normally

Replacement of burst disks was one thing I heard. I don't remember if I heard any others.

 

[Divin'Papaw]

Down here in South FL where I do all of my diving these days my LP tanks are typically filled to 3000 psi and my HP tanks are typically filled to 3600-3800 and occasionally 4000. Those are cool fills at my primary shop here in Boca Raton. They fill them slowly in a water bath and leave them for 10-15 min to cool while I wait and top them off before removing the whip. I have no issues with that. Thrilled actually. I do not request that my LP tanks be filled above 3000. My two LP85s will give me 96 cf at 3000 psi which is perfectly fine for the recreational diving that I do.

Now my three AL tanks I will bleed them down to 3000 if they are overfilled and cool to higher than 3000. Rarely have I had an issue with them being overfilled.

 

[Degenerate]

Hello. You should absolutely, positively, undoubtedly, vehemently, NEVER, EVER Overfill tanks. It is Illegal.
However...........if, a tank is overfilled. You should bleed it down to be D.O.T./O.S.H.A. compliant.
If, one of your tanks is overfilled??????? Accidently, I have attached a chart to show how potentially dangerous it can be.
Cheers.
I personally wouldn't recommend accidently overfilling Aluminum, or H.P. Steel tanks. (Seriously.)

Damn, I better go drain my doubles a bit then.
The neck stamps say 232 bar but they're sitting at a cosy 260 and 265 bar right now.

My 200 bar suit inflation cylinder accidentally got filled to slightly below 300 a little while back, I'll admit I did drain that one quite a bit, a 50% overfill does seem way too extreme.

 

[rjack321]

Primarily burst disk failure: Burst discs: Yes they burst when they shouldn't. .

I used 5250 psi burst disks in all my steels regardless of LP vs HP
I fill my LP tanks to 3200 minimum but when I really want gas I have no issues pumping them to 3800. Its just increasingly hard on my compressor.

 

[Divin'Papaw]

I used 5250 psi burst disks in all my steels regardless of LP vs HP.

Same here.

 

[Manatee Diver]

I also have 5250 burst discs on my LP85s. And most of my aluminum tanks, as that it what DGX sends out with their valves. Though when I hydro my aluminum tanks I will replace the 5250s with 5000 psi discs.