Non-steel, non-aluminum scuba tanks

[MrVegas]

They weren't a big seller,

Too bad. Seems like HP71s would have made a nice lightweight set of doubles for recreational diving. Of course, that might be a pretty small market. 71 feet is too small for most single tank divers, and most serious tech people are looking for a lot more than 142 feet in a set of doubles, I suppose. (And looking at it from the boat dive perspective, if you're trying to get two dives off of one set of doubles, it might be cutting it close, depending on the dives.)

Thanks for the response.

 

[Gone for diving]

You can always go twin LP72.
They can be over pumped,,
Not exactly super light,
but alot nicer then 120 or 130s

 

[MrVegas]

You can always go twin LP72.

I actually have some of those -- and really like them. 72s are still all around very nice. (Most places are pretty strict about keeping them at 2250 psi, though., so that's really 65 cubic feet per tank.) I was just wondering out loud about the HP71s, given some of the other items people were discussing on the thread.

 

[Akimbo]

I actually have some of those -- and really like them. 72s are still all around very nice.

Agreed. It comes down to why you are willing to pack doubles. They (72's) are great if you want redundancy within or close to NDLs. Most people would probably want more gas for serious decompression commitments.

The old-school general guideline in the US was it is hard to get bent with a single 72, for an adult male anyway.

 

[Ghost95]

Steel and aluminum will probably remain the most cost-effective materials for our lifetimes. Titanium alloys are probably the optimum material for diving, excluding cost problems.

I have often daydreamed about the ideal cylinder for recreational diving. Here is my wish list:

1. Non-corrosive material which would eliminate VIPs, oxidation contamination, reduced service life, etc.
2. Designed to be neutrally buoyant in salt water when full. The logic is that the diver would carry droppable lead to compensate for the weight of the air so they would have positive buoyancy at the end of the dive.
3. The working pressure would be based on the wall wall thickness determined by item 2, preferably in the 300 Bar/4,300 PSI+ range.
4. The volume of compressed gas would in around 1.2m³/42Ft³. The logic is that the standard recreational configuration would be low profile doubles. Triple and quad manifolds could be used for Technical diving.
5. Hemispherical ends for optimum pressure rating per unit of weight and reduced hydrodynamic resistance.
6. Outside diameter about 100mm/4". The old AGA 324 were sweet rigs except for the weight — very negatively buoyant.

View attachment 721444

I'm OK with a recreational manifold only having one DIN connection but each cylinder would have a valve to support progressive equalization. Like the AGA 324, they would be worn valve-down. Manifolds for triples and quads would support two first stages.

I knew a guy who was a Sat diver and he had a set of these tanks that he let me dive with his AGA Mask. It was allot of fun but those little tanks are deceptively heavy. I thought they'd weigh less than an 80 but it felt like they weighed three times as much. Cool thanks though.

 

[Tracy]

You can always go twin LP72.
They can be over pumped,,
Not exactly super light,
but alot nicer then 120 or 130s
View attachment 721470

I will warn you. Don't pump them too high. Anything above 3200 and you will be damaging them.

 

[Gone for diving]

Oh I don't go that high, normally 2600 -2700psi

 

[Jim Lapenta]

Transparent aluminum cylinders. Montgomery Scott gave the formula to a guy in California a number of years ago.

 

[lowwall]

Transparent aluminum cylinders. Montgomery Scott gave the formula to a guy in California a number of years ago.

It exists. It's actually an Aluminum ceramic (Aluminum Oxynitride) rather than an alloy. Very expensive to produce and so far use is primarily limited to armored windows.

Aluminium oxynitride - Wikipedia

en.m.wikipedia.org