Help Validate Facts on Overfill to LDS

[PhinDiver]

Well as somebody that doesn't get paid enough to find out the hard way when the shorter lifespan of your tank is up, rember you can get a good fill or a fast fill, not both, so leave it over night or deal with what you get.
You could be right, a steel tank probably won't explode, but I would hate to see the kneck crack and shoot out the valve.

 

[M&P+4]

I thought there was an actual tank rating/capacity and a DOT rating. The tank would be OK at the upper limit but it would be illegal to transport it over the DOT rating....

 

[ScubaSarus]

I believe DOT draws a strict line at the rated pressure and + if present. The overfill for cooling is a courtesy the next best thing is to leave them at the shop and have them top it off after the cool down.

 

[Dave in PA]

Yes, the tank pressures are set by the DOT, However, OSHA says that you can't pressurize a cylinder beyond what the DOT stamp says. Both are federal, as well as state agencies. Do people over fill tanks, I'm sure they do, but is it illegal for them to do so in the USA? Yes. Can professionals refuse to over pressurize cylinders? Sure, it's their shop. The easiest way to do so is to point out that it's against the law.

Useless trivia: One of the many charges filed against Timothy McVeigh dealt with the violation of DOT laws concerning transportation of hazardous materials.

 

[Rick Inman]

Aren't they willing to let it cool & top it off to the rated pressure? If not, why not?

If they'll do that, the overfill isn't an issue.

Sure they will. But this shop is only open from 4pm - 7pm (that's how they manage to survive in this one-horse town). People sometimes need to get in and get out with a full fill.

The issue isn't me (90% of my buddies make having a full tank a non-issue). But the other shops in town do overfills and this shop is loosing customers over it. They're good fellas, just trying to be safe, and I'm looking for a way to help them.

Is it Wayne?
Gary D.

It's the legacy of Wayne. Those 3 brothers who bought the shop only know what Wayne told them is truth. They are starting to question the "facts" though. I think they're surprised every time I survive a dive since I don't use all ScubaPro gear.

They don't get out of the pool much...

 

[MXGratefulDiver]

A pity you don't live closer ... I know one local shop that routinely fills HP cylinders to 4,000 psi and LP cylinders to 3,000 psi.

... Bob (Grateful Diver)

 

[MookieMoose]

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!!

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

 

[Rick Inman]

A pity you don't live closer ... I know one local shop that routinely fills HP cylinders to 4,000 psi and LP cylinders to 3,000 psi.

... Bob (Grateful Diver)

Yeah, but I don't have the directions to Pug's garage!

Seriously, every shop I've use in your neck gives full (or over) fills.

 

[jerryn]

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

 

[Gary D.]

Sure they will. But this shop is only open from 4pm - 7pm (that's how they manage to survive in this one-horse town). People sometimes need to get in and get out with a full fill.

The issue isn't me (90% of my buddies make having a full tank a non-issue). But the other shops in town do overfills and this shop is loosing customers over it. They're good fellas, just trying to be safe, and I'm looking for a way to help them.


It's the legacy of Wayne. Those 3 brothers who bought the shop only know what Wayne told them is truth. They are starting to question the "facts" though. I think they're surprised every time I survive a dive since I don't use all ScubaPro gear.

They don't get out of the pool much...

I should walk in wearing one of those freaky Halloween masks because I don't have any SP stuff. My my how do we survive?

Gary D.