300 bar DIN tanks in the usa

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Homunculus

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Messages
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Location
Avon, CT, USA
# of dives
50 - 99
hi all,
i just got a new DIN reg and wondering why i can't find any tanks with 300 bar pressure (4500 PSI). then i've read somewhere that it's illegal in the USA to transport these tanks. Does anyone know anything about this issue? how can this law be enforced?
Is it illegal to buy an empty tank as well? If not, where can one buy it? I spend an hour looking for places that sell them but so far no luck. :shakehead
if 300 bar DIN tanks are indeed nowhere to find in the US, what's the point of DIN regs (in the US)?
Thank you
 
There are no scuba tanks currently made and approved for use in the USA with a 4500 psi working pressure. And even if there were, no dive shop would likely fill them to that pressure. 4500 psi industrial tanks exist and they are prefectly legal to transport. These regulations are enforced by DOT.

Yoke regs are less secure all the way around. DIN valves avoid blown o-rings.
 
rjack321:
There are no scuba tanks currently made and approved for use in the USA with a 4500 psi working pressure. And even if there were, no dive shop would likely fill them to that pressure. 4500 psi industrial tanks exist and they are prefectly legal to transport. These regulations are enforced by DOT.

Yoke regs are less secure all the way around. DIN valves avoid blown o-rings.

Luxfer makes a 4250 psi aluminum fiber wrap cylinder for SCUBA.

Lee
www.seapearls.com
 
If they're not legal to transport, then practically every fire engine is breaking the law.

All the best, James
 
Umm fire dept. scba cylinders are not approved for UW use. They also don't use DIN valves.

Anyone actually filling those fancy Luxfers to their rated pressure? (which is still less than 4500 although it is 300 bar) They tried something similar before - years ago - how many of this latest incarnation have they sold?

Also looks like they have peculiar valves 0.875x14 threading is weird
 
Mikhail Frenkel:
if 300 bar DIN tanks are indeed nowhere to find in the US, what's the point of DIN regs (in the US)?
Thank you

I have DIN on all my tanks and regs. But tanks are rated to 3500 psi. There are many advantages, in my mind, to have DIN over yoke other than higher pressure.
 
rjack321:
Umm fire dept. scba cylinders are not approved for UW use. They also don't use DIN valves.

<snip>
Indeed they do not have DIN valves. However, I was responding to the implication that it was the pressure of the cylinder that precluded transport.

I was not aware that a cylinder needed a special DOT approval for underwater use. In fact our Scott and Interspiro composite cylinders have no restriction listed for underwater use, either in their Exemption or user manual.

All the best, James
 
This thread is ancient, I know. In one post the thread size of "7/8 inch 14 TPI" is referred to as "weird". I'm no expert, but from personal experience with 3,500 PSI (*not 3,442 PSI*) tanks, this was the threading for the old HP tanks/cylinders (3,500 PSI). The newer HP cylinders use the "standard" currently for scuba tanks which is 3/4" NPS. The 7/8"-14 is UNF threading and is smaller in diameter than the 3/4" NPS.

FWIW.

--HC
 
This thread is ancient, I know. In one post the thread size of "7/8 inch 14 TPI" is referred to as "weird". I'm no expert, but from personal experience with 3,500 PSI (*not 3,442 PSI*) tanks, this was the threading for the old HP tanks/cylinders (3,500 PSI).

Since 3500# and higher scuba tanks are no longer made, it is weird to run across them. Since it is the DOT standard for 3500# and higher scuba tanks, if they are ever made again, they may lose their weird status.
 

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