Overpressurizing / Overfilling steel tanks

[Genesis]

Because we can. Thats why. You do what you want, and we do want we want...
Nobody is telling you that YOU have to overfill.

BTW, for me, I overfill so I can get two dives in on one set of doubles, and still have thirds for the second dive. Of course, these dives are not real deep, nor are they real long. Just makes things easier logistically on small boats.

Yeah, I don't normally need to do that with my HP100s. Then again I sip gas. I can usually get 2 NDL dives on a pair of 72s, but thirds on the second one isn't going to work real well. On the 100s its not a problem.

The 100s are HPs though which I am not going to be overfilling... but I do go right to the correct pressure when cooled.

 

[blacknet]

Hello,

Seems to me that those diver who overfills tanks are a bunch of self centered tightwads who are to cheap to buy proper gear, push the limits and dive recklessly.

Ed

 

[Boogie711]

Seems to me that those diver who overfills tanks are a bunch of self centered tightwads who are to cheap to buy proper gear, push the limits and dive recklessly.

Well - I would say something like "I guess I'm a reckless, self centred tightwad and never realized it," but then I considered the source. This is the same man who once wrote that "Getting a fill, throwing the tank into your trunk then driving to a dive site can be enough temp to condem your tank(s), easily."

My source

So forgive me if I don't put a whole lot of stock into just about anything you happen to say regarding tank maintenance.

 

[blacknet]

So forgive me if I don't put a whole lot of stock into just about anything you happen to say regarding tank maintenance.

Obviously you care enough to make a silly post about it.

And for the record that info came directly from Rainreg.

Ed

 

[GDI]

No one has ever died from a tank exploding on them.

Lots of divers have drowned by running out of air.

'nuff said.

Sorry Boogie you incorrect on that point. There was a fatality in Canada a few years back, a dive shop owner in Calgary diving a lake just south of the city had a cylinder bust open at the valve junction. He was noted for overfilling tanks.

 

[DA Aquamaster]

Sorry Chris, But I dont believe OVERFILLING had anything to do with that incident. By reading the article, one can see that the tank did NOT have a current inspection. The cylinder was rusting from the inside, and an internal inspection would have found this...

So you agree that following the industry standard (it's a voluntary standard, not a regulation) of doing an annual VIP is important as is following the regulation requiring a hydro test every 5 years. However, I need to clarify this, you feel it is OK to ignore the regulation limiting the fill pressure to what is stamped on the shoulder plus 10% if the tank is plus rated just because they fill similar tanks approved in europe under different engineering standards to higher pressures? Sounds like picking and choosing your saftey rules to me.

It would be interesting to know what pressure the tank failed at as the normal service pressure, by your own admission, allows a large saftey margin. The rusty tank in question may well have survived a fill to its normal service pressure but not an overfill. But we won't know as unfortunately the witness died of severe head and chest trauma.

In my opinion the approved method of overfilling should include the steps of dropping off the tank at the dive shop and then going several blocks away for a beer while you wait for the tank to be overfilled or until you hear a large boom.

 

[GDI]

:doctor: You know it just amazes me that people think engineers are wrong. Yeh I have no problem noting that the Titanic was built by professionals and Noah's Ark was built by a amature. (Granted that Noah had some divine plans and supervision to work with) There is a reason that the fill pressures are placed on cylinders and why we use a different standard here in North America than in Europe. But since we are looking at what overfilling a tank does and the risk involved what about looking at what your reg is doing when that cylinder is overpressurized. The reg is only set up for optimal performance at 300 bar. Excessive pressure on the seat places the reg into a potential failure possibility. I have yet to see where overfilling a cylinder to such high pressures has benefited the diver. I have yet to turn a dive using my hp 120's, my e-series 120's or even my 98's all filled to their rated psi when diving with people who overpresure their tanks. The reg will not perform as it should against that kind of pressure. Your attempt to dive longer using higher pressure fills decreases the regs performance and only causes the diver to breath worse. Maybe I'm just that good on my SAC rate? You want more dive time carry more tanks!

 

[Boogie711]

"The reg is only set up for optimal performance at 300 bar.

300 Bar = 4,410 PSI.

When I say I overfill my tanks, I'm sure as heck not filling them to 4,400 psi.

 

[DeepScuba]

Well DA:

The rusty tank in question may well have survived a fill to its normal service pressure but not an overfill.


I think you're pushing it. In fact, I KNOW you're pushing it. The point is the tank was bad, period. Filling it 1500 could have easily done the same thing.

If a tank is going to fail with even a 30% overfill, it was already junk long ago.

There's no way on earth that any tank (unless faulty from the outset, or as I mentioned, not maintained/checked for obvious failure) will explode with this overfill. They simply aren't made that poorly.

Talk about picking and choosing!

GDI:

Let me ask you how my regs will work with a 3000PSI ALU80 fill but not with a 3000 - 3200PSI overfill on my LP104's?

Sound silly to you now?

 

[DeepScuba]

I'm still waiting for the REAL difference, wall thickness etc between the PST LP104 and E8-130's.

Anyone have those specs?