High Pressure Vs Low Pressure Steel tanks

[lowviz]

To add yet another thing to consider, Dutch Springs (quarry near me) won't fill my double 72's past the reference pressure of 2250. So I get short dives on these tanks at Dutch, but nice dives (courtesy of my LDS) in the ocean.

-You pretty much have everything you need to make a good choice. Figure out what applies to your situation and go for it.

 

[davetowz]

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.

 

[lowviz]

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.

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?)

 

[Topbodz]

Topbodz, one thing that should register in your consideration is "Do I have an LDS that can fill my HP steel to 3442?"

Most small LDS have compressor that will fill to 3000psi.

As far as I know, there is one LDS in Phoenix area that will / can fill a bottle to 3442.

Therefore, I always have a fill of 3000psi, which cools to 2700 psi, which is 2700/3442 * 100cf = 78cf . . . so that inability to fill to capacity makes my 100s into 80's.

Geez Jax, I had never considered that. I assumed that shops would be adequately equipped to do the job right.....

I'm not even a shop but I bought a compressor (Bauer K15) that is set to 4000 psi, but CAN go to 5000 psi.

I fill 3442s to 3550 or so, then let them cool down while I'm filling other tanks, then come back & top them off to 3500 psi.

I know that the lds I USE to take my tanks to gave me short fills..... :-( Now I fill my own!

 

[Jax]

Geez Jax, I had never considered that. I assumed that shops would be adequately equipped to do the job right.....

I'm not even a shop but I bought a compressor (Bauer K15) that is set to 4000 psi, but CAN go to 5000 psi.

I fill 3442s to 3550 or so, then let them cool down while I'm filling other tanks, then come back & top them off to 3500 psi.

I know that the lds I USE to take my tanks to gave me short fills..... :-( Now I fill my own!

Adopt me?

In regards to short fills - my local guy has an electric compressor that auto shuts off at 3000. When the tank cools, it drops, but not enough to trigger the compressor to top off. It's just the way it is. I'm 200 miles from Phoenix, and don't find it convenient to go to the shop that will fill HP even when I am there. But I knew all this going in, so I am okay with it.

However, when I go to Mexico, they fill me to 3600.

 

[Jax]

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.

As I understand it, the same tank that is rated for 3442 here in the US is rated for 5000 psi in Europe. The US limits are arbitrary and have something to do with the transportation of tanks. People don't like that.

Someone more in the know please embellish or correct me . . .

 

[Mitchell Teeters]

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.

tank police!

sent via nookcolor N2A.

 

[Colliam7]

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.

Lowviz, sorry I don't think I made my point clear. I am certainly aware of using transfilling, from HP to LP tanks, to adjust blends. My point was just that, if the OP was referring to that specific fill issue, I didn't pick up on it, probably because I seldom have a need to blend / tweak by transfill. Plus, because I only use HP tanks, there usually isn't enough of a pressure gradient to make the process productive.

 

[lowviz]

Colliam7,

You were clear, my wordy response was more for the OP's benefit. -Thanks

 

[Topbodz]

Adopt me?

I'm 200 miles from Phoenix,
However, when I go to Mexico, they fill me to 3600.

Done!:cool2: But you'd have to come down to Sunny S. Florida a little further than Phoenix - We have warm water! lol