Filling LP tanks to high pressure

[Omisson]

If some nit-wit hits your car while you have one of your highly maintained, clean, rust free, vip'd and hydro'd tanks in it and breaks the valve you'll come to realize why displaying the power you are carrying is relevant. If that requires old and deficient tanks, so be it. Just don't think you are immune because your tanks are good. Sh!t happens.

If that happens it:

A) has nothing to do with the tanks in and of themselves, the pressure in the tanks, or any failure by them- which is the point of this thread.


B) there would be no damage difference (perceptibly) from the 3500 psi filled LP and 3500 psi filled hp tank in such accident - both would unleash and cause the same destructive damage.... Again the implied point has NOTHING to do with this thread.

So how does this factoid contribute to the discussion? It doesn't.

If someone didn't know a metal container under pressure when forcibly ruptured was dangerous that's not lack of scuba knowledge that's Darwinian natural selection waiting to happen.

In any event, not one shred of proof has been shown that a well maintained, cave filled (3500 psi) LP steel tank in Hydro and VIP without rusting or manufacturing metallurgical flaw is :

1) inherently any more dangerous than one filled to spec

2) has ever ruptured according to DOT

3) has a significantly reduced service life

THAT was the point of this thread. This of course is not dispositive- but is certainly informative to the subject at hand.

Dan-O

 

[AfterDark]

If that happens it:

A) has nothing to do with the tanks in and of themselves, the pressure in the tanks, or any failure by them- which is the point of this thread.


B) there would be no damage difference (perceptibly) from the 3500 psi filled LP and 3500 psi filled hp tank in such accident - both would unleash and cause the same destructive damage.... Again the implied point has NOTHING to do with this thread.

So how does this factoid contribute to the discussion? It doesn't.

If someone didn't know a metal container under pressure when forcibly ruptured was dangerous that's not lack of scuba knowledge that's Darwinian natural selection waiting to happen.

In any event, not one shred of proof has been shown that a well maintained, cave filled (3500 psi) LP steel tank in Hydro and VIP without rusting or manufacturing metallurgical flaw is :

1) inherently any more dangerous than one filled to spec

2) has ever ruptured according to DOT

3) has a significantly reduced service life

THAT was the point of this thread. This of course is not dispositive- but is certainly informative to the subject at hand.

Dan-O

POST #1
"I'm sorry if this has been covered before, but I am looking for a definitive answer. I just inherited 2 LP Faber 130s that has the 2400+ symbol on them and the guy told me you could pump these tanks up to 4000psi in "cave" country. Then I ran across a thread that said LP tanks are made with a different material than HP tanks. So are we wrong about pumping the tanks up past their rated pressure that we have heard and done for many years?"

If you were paying attention you’d know that the point of this thread was whether the op could/should fill his 2400psi + tank to up to 4000psi. IMO he should be aware of the power he is dealing with. It's part of an informed decision.

 

[Jared0425]

I said that people told me that they could fill my tanks up to 4000psi. I have no intention of filling them past 3500psi. I put 3442 valves on them. They also have the plus rating on them and they are almost brand new and not in need of hydro for another 3 years.

 

[Omisson]

POST #1
"I'm sorry if this has been covered before, but I am looking for a definitive answer. I just inherited 2 LP Faber 130s that has the 2400+ symbol on them and the guy told me you could pump these tanks up to 4000psi in "cave" country. Then I ran across a thread that said LP tanks are made with a different material than HP tanks. So are we wrong about pumping the tanks up past their rated pressure that we have heard and done for many years?"

If you were paying attention you’d know that the point of this thread was whether the op could/should fill his 2400psi + tank to up to 4000psi. IMO he should be aware of the power he is dealing with. It's part of an informed decision.

If YOU were paying attention you would realize nothing changes what I said (or any of the others familiar with cave fills)- namely:

There is NO DOCUMENTED RISK greater than the risk associated in using ANY (including filled to specification) other STEEL scuba tank- so long is it is:

A) properly maintained
B) in Hydro
C) in VIP
And
D) not shot at, dropped from height, put in a garbage crusher, hit in an auto accident, left in a pressure cooker, roasted in an oven forge or kiln, etc...

Just like ANY OTHER FILLED SCUBA TANK.

So the answer is: Statistically speaking

A) you face no greater dangers in using an HP Steel Cylinder filled to it's marked capacity as a Cave Filled LP Steel Cylinder (filled to under 4000 psi), all other factors being equal.


B) Furthermore, the potential risks in damage, force, etc., are the same for either tank.


THAT is the point of this thread. Nothing you said is relevant to that point.

 

[AfterDark]

If YOU were paying attention you would realize nothing changes what I said (or any of the others familiar with cave fills)- namely:

There is NO DOCUMENTED RISK greater than the risk associated in using ANY (including filled to specification) other STEEL scuba tank- so long is it is:

A) properly maintained
B) in Hydro
C) in VIP
And
D) not shot at, dropped from height, put in a garbage crusher, hit in an auto accident, left in a pressure cooker, roasted in an oven forge or kiln, etc...

Just like ANY OTHER FILLED SCUBA TANK.

So the answer is: Statistically speaking

A) you face no greater dangers in using an HP Steel Cylinder filled to it's marked capacity as a Cave Filled LP Steel Cylinder (filled to under 4000 psi), all other factors being equal.


B) Furthermore, the potential risks in damage, force, etc., are the same for either tank.


THAT is the point of this thread. Nothing you said is relevant to that point.

So we have different opinions big deal. Opinions are like ...................

 

[Omisson]

So we have different opinions big deal. Opinions are like ...................

We have a difference of opinion?

You are entitled to your own OPINION not your own FACTS.

You have no facts to support any opinion that reaches a different conclusion than what I stated.

So if you want to have the opinion that "it is unsafe to cave fill LP steels" your opinion is unsupported by facts, thus Making it a useless opinion. Whereas the opinion that it is "as safe as the use of regular hp steels filled to specs" - is supported by the record, the "facts".... Thus has much more weight.

 

[AfterDark]

We have a difference of opinion?

You are entitled to your own OPINION not your own FACTS.

You have no facts to support any opinion that reaches a different conclusion than what I stated.

So if you want to have the opinion that "it is unsafe to cave fill LP steels" your opinion is unsupported by facts, thus Making it a useless opinion. Whereas the opinion that it is "as safe as the use of regular hp steels filled to specs" - is supported by the record, the "facts".... Thus has much more weight.

I presented the fact of what happens when a tank burst. The condition of the tank the reason it burst is irrelevant, it is only for illustration purposes of the power. Other than that I presented the facts of what I do with my tanks. And the + 10% over rated pressure. If there are any other facts that you are attributing to me, than you are once again mistaken and I ask you to please quote those post containing those "facts".

 

[Omisson]

I presented the fact of what happens when a tank burst. The condition of the tank the reason it burst is irrelevant, it is only for illustration purposes of the power. Other than that I presented the facts of what I do with my tanks. And the + 10% over rated pressure. If there are any other facts that you are attributing to me, than you are once again mistaken and I ask you to please quote those post containing those "facts".

The BOTTOM LINE question asked in THIS THREAD is:

(paraphrasing)

Is there any GREATER danger in cave filling an LP tank, as opposed to the rated fill of an HP steel or Aluminum...

Do we agree THAT is the intention of the question asked ?

1) The question must presume the commonality of the condition of tanks, i.e industry standards of care, in hydro, VIP, not being rusted, not from a flawed metallurgical or construction batch.... Because those factors are presumptions in the DOT specs.

2) reasonable cave fills (i.e. Not over 4000 psi, usually averaging 3500 psi) such that burst disk values are not modified nor exceeded.


If so, then the answer is....

Statistically speaking, NO greater danger.
Practically speaking, NO greater danger.
Scientifically speaking, NO greater danger empirically.

There may be marginal and inconsequential effects of such repeated filling practices which appear to not be detrimental in the useful life cycle of such tanks nor have they presented any safety consequences so far. This despite prolonged repeated and widespread variety of such tanks in the largest concentrated area of their use- Cave Country in Florida.

THAT the point of this whole thread.

Dan

 

[halocline]

You have no facts to support any opinion that reaches a different conclusion than what I stated.

That's not entirely true. It is true that there is no documented case of a cave fill on a 3AA tank resulting in catastrophic failure, but that does not mean that there is inherently no greater risk of one happening than with a 'spec' filled tank. The fact that occasionally scuba tanks burst at test pressure during hydrotest is one indication of an increased risk. (granted, it's rare but not unheard of) And I'm pretty confident any structural engineer (not only Luis H) would be able to demonstrate how an overfilled 3AA tank has a measurably lower tolerance of impact without bursting. This means that transporting overfilled tanks by auto, anyhow, does carry an elevated risk.

What the facts support is, at least at the time of this thread, that the increase in risk of cave filling tanks is slight enough so that many many people have been able to do it without any incident, for years. Let's hope that continues!

 

[Omisson]

That's not entirely true. It is true that there is no documented case of a cave fill on a 3AA tank resulting in catastrophic failure, but that does not mean that there is inherently no greater risk of one happening than with a 'spec' filled tank. The fact that occasionally scuba tanks burst at test pressure during hydrotest is one indication of an increased risk. (granted, it's rare but not unheard of) And I'm pretty confident any structural engineer (not only Luis H) would be able to demonstrate how an overfilled 3AA tank has a measurably lower tolerance of impact without bursting. This means that transporting overfilled tanks by auto, anyhow, does carry an elevated risk.

What the facts support is, at least at the time of this thread, that the increase in risk of cave filling tanks is slight enough so that many many people have been able to do it without any incident, for years. Let's hope that continues!

Ughhhh.

Do I need to explain basic hypothesis testing?

In order for you to make your assertion YOU have to have data to Test support your claim empirically.

The data as you admit, DOES NOT support your claim.

This makes it an invalid hypothesis. Therefore:

Practically (meaning in the practical experience of the use of the custom) there is no greater danger.

Scientifically (meaning no data on record or in the applied physics of the manufacture of the structure, in the conditions described) there is no greater danger.

And

statistically (meaning an examination of the historical record of incidents involving such conditions) there is no greater danger.

What I said is factual. There is no "partial" to it.