Help Validate Facts on Overfill to LDS

[roakey]

Let me clarify, by "overfill" you're just talking about filling a couple hundred PSI over the cylinders rated pressure (STP) an NOT about stuffing 4k in a 2400 PSI cylinder, correct?

I think everyone's focusing on the word "overfill" and thinking cave fills, not a couple hundred PSI...

Roak

 

[Double_D]

Tell them to take a look at the DOT regulations. The text of the regulations themselves state that the rated tank pressure is for 70 F. At higher temperatures it is perfectly acceptable to have higher pressures.

Cam


I'm not sure why that follows. The issue is pressure on the tank wall, not the number of molecules within the tank. I thought the volume rating was for the tank at maximum fill pressure at 70 F, but the maximum pressure as given by DOT is at any temperature. But perhaps I'm wrong. Do you have the DOT citation which says that a tank fill can be above rated pressure at higher temperatures?

Jerry

It should follow: The number of molecules will vary in proportion to the pressure in the cylinder. Unless the gas inside is something other than good old filtered breathing air (with a different atomic weight and mass), solving for pressure - temperature and the cylinder volume are the only remaining variables.

 

[PhotoTJ]

Fill 'em in a freezer. You won't get a short fill.

 

[toodive4]

LP Steels have a +10 rating stamped right on them. This means they can be safely filled to 2640 (instead of 2400) without any problem. My LDS pumps mine all the way to 3000 for me and they've been doing it for years. LDS's with knowledgeable staff know this can be done without any problem. Long before the tank would explode... the burst disc would blow... causing no injury to anyone... Sounds like you're going to a shop run by dingalings.

Ken

Augh! Sick of searching, and wading through old threads to try to find some posts I remember, hence this redundant thread.

Can anyone help me with some hard data on this subject?

I was saying to my LDS last night, about overfills, that it's OK to run my LP Steel Fabers over a couple hundred PSI, so they'll cool to the rated pressure. I said that I had read that there is no record of a Faber steel exploding (it's that old batch of AL). I said that I had read that the only detrimental thing to overfilling a couple hundred PSI is the stress on the steel shortens the life of the tank a bit, but that there was no risk to the LDS to put 2800PSI in my 95, so it will cool to 2640.

They said, can I document my postulations?

Can I? Can anyone show me to some data, or a document that validates what I'm suggesting?

Thanks!!

 

[lamont]

Tanks, no matter what hey are made of, shouldn't fill over their recommended pressure. Now that said if you overfill your tank a couple hundred psi it isn't going to explode (provided that is properly maintained hydro and vis), they constructed to take about 5000 psi before exploding. However regularly overfilling you tank could reduce the lifespan of it.

they are constructed to take at least 10,000 fill cycles to around 5000 psi before failing and they must fail in a leak-before-burst failure mode.

 

[Lil' Irish Temper]

LP Steels have a +10 rating stamped right on them. This means they can be safely filled to 2640 (instead of 2400) without any problem. My LDS pumps mine all the way to 3000 for me and they've been doing it for years.

Ken

Using a LP 95,

If you fill it to 2400 you only get 86.4 cubic feet at 2400.
Now if you do 2400 + 10% = 2640 is 95 cubic feet.

I usually fill mine to 3200, and that gives me 115 cubic feet of gas.

If I remember right the tensile strength is different in Europe then the US.

But I think Roak is right about focusing on the word "overfill"

 

[NutJob]

Hmmm, I've been reading a lot of stuff on this site before I joined, everyone seems to hate the LDS. But then they want them, (the LDS), to overfill the tanks, against DOT regs, that they didn't buy at the LDS to begin with, putting themselves at risk both physically, and from a legal standpoint, in an actionable position, as well.

So, you propose to put increased wear and tear on their compressor, (Higher pressure fills=increased metal fatigue), and then, assuming no one gets any body parts blown off, you will doubtless buy new tanks, (to replace the ones that failed hydro), online again.

Does that about cover it?

 

[Lil' Irish Temper]

Hmmm, I've been reading a lot of stuff on this site before I joined, everyone seems to hate the LDS. But then they want them, (the LDS), to overfill the tanks, against DOT regs, that they didn't buy at the LDS to begin with, putting themselves at risk both physically, and from a legal standpoint, in an actionable position, as well.

I don't hate my LDS, just some of the people who work there. They also have "The right to refuse service" too. If it could be such a problem wouldn't the DOT be cracking down on it?

So, you propose to put increased wear and tear on their compressor, (Higher pressure fills=increased metal fatigue), and then, assuming no one gets any body parts blown off, you will doubtless buy new tanks, (to replace the ones that failed hydro), online again.

I don't see anyone standing there holding a gun to their heads, screaming "FILL IT OR DIE" Like you said it's "Their compressor" so they can so NO at anytime. We aren't filling our tanks they do.

Does that about cover it?

Should cover it, and Welcome to ScubaBoard

 

[PhotoTJ]

Hmmm, I've been reading a lot of stuff on this site before I joined, everyone seems to hate the LDS. But then they want them, (the LDS), to overfill the tanks, against DOT regs, that they didn't buy at the LDS to begin with, putting themselves at risk both physically, and from a legal standpoint, in an actionable position, as well.

So, you propose to put increased wear and tear on their compressor, (Higher pressure fills=increased metal fatigue), and then, assuming no one gets any body parts blown off, you will doubtless buy new tanks, (to replace the ones that failed hydro), online again.

Does that about cover it?

Bitter, party of one, your table is ready.

 

[Rick Inman]

...everyone seems to hate the LDS.

Some people don't care for their LDS. A very few might even hate them. Most people do not hate their LDS.

...But then they want them, (the LDS), to overfill the tanks,

No, we want to end up with a full fill, not a short fill.

...that they didn't buy at the LDS to begin with,

Most tanks are purchased from their LDS due to shipping costs. That's where I got mine.

...putting themselves at risk both physically, and from a legal standpoint, in an actionable position, as well.

No physical risk. There is this new invention called a burst disk. Again, no steel tank has ever exploded. There is much greater risk just driving to the shop.

...So, you propose to put increased wear and tear on their compressor,

I think the compressor can handle 2800psi. There is some ware and tear in every fill, which is why I give them some money for air.

...and then, assuming no one gets any body parts blown off, you will doubtless buy new tanks, (to replace the ones that failed hydro), online again.

Can you name ONE time a body part was blown off giving a fill that cools to full? Or even 200psi over. Heck, can you name a tank that caused a missing limb at 500psi over? (Remember, we already established that we're not talking about that one bad batch of ALs.)
It just doesn't happen.

...Does that about cover it?

I'd say it does, NutJob.