Question Is there a high pressure version of LP50's?

[jstotz]

Does anyone manufacture a steel high pressure (3442psi) cylinder for sale in the US with similar dimensions to a steel LP 50? (I.e. ~5.5"x25")

Such a tank, assuming similar wall thickness, would have an air capacity around 63.5 cuft.

Perhaps there is such a product but it's usually only used for rebreathers?

 

[rjack321]

There is no such tank. Just fill your 50s to 3500 and call it good.

 

[sinidive]

Faber makes tanks that are quite near that, not sure how easy to buy in the US though.

There is a 8L 300bar cylinder with 140mm diameter and 680mm length (tiny bit longer). Note that Faber also makes wider 8L 300bar cylinders (171x470mm). That cylinder should weight around 11kg.

 

[jstotz]

There is no such tank. Just fill your 50s to 3500 and call it good.

...
This is blowing my mind. Recently in Puerto Rico the shop filled our rented alu 80's to 3,500 and my mind was blown. THEN my PR friend said, "geez he must not like you; he fills mine to 4,500psi"

I had of course heard of cave fills but naively thought it only happened in "deep cave country" in shady shops and only with steel.

Apparently, this is much more common than I thought.

I guess it's not that shocking if they're hydrotested to 5/3 working pressure, and we have 5kpsi burst discs for safety.

 

[jstotz]

Faber makes tanks that are quite near that, not sure how easy to buy in the US though.

There is a 8L 300bar cylinder with 140mm diameter and 680mm length (tiny bit longer). Note that Faber also makes wider 8L 300bar cylinders (171x470mm). That cylinder should weight around 11kg.

Early on I got a guy in the UK to send me his 12L 300bar(4,350psi) Faber via Facebook marketplace.

Paid him to ship it over on the flotilla. Apparently, highly upsetting to the USDOT if they ever found out.

Sucker is near 50 lbs full and something like -15lbs buoyant. I thought it was the coolest thing in the world until the original hydro expired and I realized no one would rehydro it stateside .

Now I have a very expensive paperweight and conversation piece. Another of my brilliant ideas.

 

[jstotz]

Faber makes tanks that are quite near that, not sure how easy to buy in the US though.

There is a 8L 300bar cylinder with 140mm diameter and 680mm length (tiny bit longer). Note that Faber also makes wider 8L 300bar cylinders (171x470mm). That cylinder should weight around 11kg.

TLDR: impossible to buy directly from any online shop in Australia or the UK and have shipped directly to US (I tried several times).

I did have a scheme where I was going to make nice with that same Facebook marketplace guy in the UK and pay him to reship them to me, but that's high shipping costs for tanks that will have to be sent back over for retesting in 5 years.

 

[grf88]

There is no such tank. Just fill your 50s to 3500 and call it good.

Just make sure you have a suitable burst disc.

 

[rjack321]

...
This is blowing my mind. Recently in Puerto Rico the shop filled our rented alu 80's to 3,500 and my mind was blown. THEN my PR friend said, "geez he must not like you; he fills mine to 4,500psi"

I had of course heard of cave fills but naively thought it only happened in "deep cave country" in shady shops and only with steel.

Apparently, this is much more common than I thought.

I guess it's not that shocking if they're hydrotested to 5/3 working pressure, and we have 5kpsi burst discs for safety.

Filling al80s to 4500 is playing with fire
3AA steel tanks are another matter.

Do not import EU 300 bar tanks to the US unless you are prepared to fill them yourself and basically forgo hydros. ISO tanks are a mixed bag, most fill stations will have no idea and who knows the extent they will remain legal in North America at all.

 

[SouthernSharktoothDiver]

@jstotz Where are you going for your hydros? I've never asked, but my local hydro place is generally rather friendly and accommodating, and I suspect if they were shown the european standards, would likely cert them up to that. Point being, are you going direct to the hydro place, or are you going through your LDS?

 

[Nick_Radov]

...
This is blowing my mind. Recently in Puerto Rico the shop filled our rented alu 80's to 3,500 and my mind was blown. THEN my PR friend said, "geez he must not like you; he fills mine to 4,500psi"

I had of course heard of cave fills but naively thought it only happened in "deep cave country" in shady shops and only with steel.

I'm not an expert on the materials science but my understanding is that over filling aluminum tanks to that level isn't real smart. Aluminum doesn't snap back after deformation like steel does, so if aluminum is stressed beyond a certain limit then the structure can be permanently damaged. This progressive weakening of the metal won't necessarily be obvious until the next hydro test.