High Pressure Vs Low Pressure Steel tanks

[Scared Silly]

That very same tank (if ordered by a different vendor) may have a 3000psi service rating, -my LDS won't exceed 3000 for a fill...

3000psi cools to 2800 so: (72-7.2)*2800/2250 = 80 cuft. (like they were always meant to be?)

huh?? are you trying to repeat the well debunked myth that a cylinder sold in the USA is LP but europe is HP? Those who have actually talked to the mfg or distributer know that the cylinders while having the same physical size actually have a different material composition which is what makes them HP and not LP.

I have some old LP 72 which I will fill to 2640psi (when cooled to 72F) but rarely beyond that. I have been known to put 3000psi in my newer LP cylinders.

 

[BabyDuck]

Just curious why the legality of overfilling a tank never gets a mention in these threads. 49 CFR prohibits filling beyond rated service pressure and also outlines the fines and punishment for doing so yet it is a common occurrence.

i think that's for commercial hauling purposes. since i'm not hauling my tanks commercially, i want my lp's filled to 3600. end of story (for me - feel free to do as you wish with yours!).

 

[lowviz]

huh?? are you trying to repeat the well debunked myth that a cylinder sold in the USA is LP but europe is HP? Those who have actually talked to the mfg or distributer know that the cylinders while having the same physical size actually have a different material composition which is what makes them HP and not LP.

I have some old LP 72 which I will fill to 2640psi (when cooled to 72F) but rarely beyond that. I have been known to put 3000psi in my newer LP cylinders.

Not really, To be perfectly honest with you, I'm rationalizing the fact that I see no problem in filling my four cylinders to three grand like they have been for the last 30 years, in constant hydro.




-steel has an elastic limit, aluminum and its alloys do not.

 

[oxyhacker]

Never gets a mention? My impression is it gets discussed incessantly.

The CFR only applies to tanks in commercial service. Privately owned cylinders not being used in commerce are not covered, so the owner (or a diveshop, acting on the owner behalf, is free to overfill it . That doesn't make it safe, or wise, but it is not illegal. The same thing applies to hydros - it is perfectly legal to fill a privately owned tank that is out of hydro (though once again, neither safe or wise).

Used in commerce normally means being used to transport a gas which is being sold although it probably also includes a tank which is being rented. Paying a shop to fill a privately owned does not put the tank in commerce any more than buying a tank full of gas for your car makes it a commercial vehicle.

Oh, mild overfills to compensate for cooling are also legal, even on tanks in commercial service.

Just curious why the legality of overfilling a tank never gets a mention in these threads. 49 CFR prohibits filling beyond rated service pressure and also outlines the fines and punishment for doing so yet it is a common occurrence.

 

[irishsquid]

... warm water! lol

Does not exist as far as Jax is concerned!

 

[lowviz]

...//....My impression is it gets discussed incessantly....//.....

Probably because there is no definitive work on this subject. Have you ever considered publishing the Oxyhacker's guide to all scuba tanks past and present?

I own Vance Harlow's OXYGEN HACKER'S COMPANION From AIrspeed Press and enjoy reading all the extra comments and arcane information that you put into it. How about doing the same thing for cylinders? I'd like to see history, stories, manufacturers, materials, etc. -No fill station would be without one.

 

[Topbodz]

Does not exist as far as Jax is concerned!

OH! S. Fla East Coast.... I'd say about 9 months out of the year you dont even need a wetsuit....

it exists trust me! :cool2:

 

[irishsquid]

OH! S. Fla East Coast.... I'd say about 9 months out of the year you dont even need a wetsuit....

it exists trust me! :cool2:

Oh Yeah, I know it does. Read her status. Jax could get cold in a dry suit in a hot tub. IJS

 

[Topbodz]

Oh Yeah, I know it does. Read her status. Jax could get cold in a dry suit in a hot tub. IJS

Lmao! :laughing:

 

[DepthCharge]

In a pinch, there is usually a way to transfill the mix you want as long as you have one or two full HP cylinders to top up the pressure. The fill order matters. Nothing worse than charging in the wrong order and ending up "can't get there from here". Wrote a program for this, just spin the dials, would gladly share if it wasn't for the legal issues involved.

No magic, can be done with a calculator also...

Nice, mine is just a spread sheet