Purchasing air tanks

[striper]

I started on scuba about three years ago and I have purchased all my personal equipment except for the air tanks. I believe the steel tanks will be okay to start out with, the weight isn't an issue. My question is the price of the tanks, is there performance or safety build into the more expensive tank construction or is it the durability, quality and more fills that dictate the higher price tank price.


Thanks,
Striper

[j yaeger]

if you're serious...
go with steel-worth the cha-ching
have fun
yaeg

[Superlyte27]

You get what you pay for.

[phillybob]

High pressure steel. 120's are nice. Relatively small package. Lots 'o' gas !!

[Jim Lapenta]

I like LP85's, 95's, and the good old Lp 72's. You can get those cheap and they last forever. I have two from 1953 and 55 that are still in service.

[LowDrag]

Check out this thread, there is some good info going on over there.

HIGH PRESSURE TANK vs LOW PRESSURE TANKS...?

[spectrum]

Striper

For New England diving Steel is more than OK, they are THE way to go. Full story here.

HP/LP and size are well covered. The right size for YOU is the best size. HP is the most efficient package. LP has some cost and ease of fill advantages but averaged out over time my money is still on HP. I have had no trouble procuring HP fill locally.

Pete

[Teller]

I prefer Faber. I think worthington flash rust very easily. I dont know much about the PST line.

[macado]

Here in New England steel tanks would be the most preferred due to their buoyancy characteristics. You won't need as much lead / weight compared to when you dive with a typical Aluminum 80 (AL80) that a lot of dive shops rent. When wearing a thick wetsuit or drysuit steel tanks are great because of this.


Many divers up here also prefer higher capacity tanks (100cf, 120cf or even 130cf) for longer and deeper dives. For example, an AL80 (~3000psi) and HP100 (~3400psi) steel are about the same size however the steel tank will have approximately 20cf more air. It's also heavier so you won't need to carry as much weight like stated above. They do make bigger aluminum tanks (AL100 for example) but they're way too buoyant and I wouldn't recommend them.


Nevertheless, buying aluminum tanks are not necessarily a bad thing. Often times you can get them at much cheaper prices than steel. A lot of dive shops might sell used AL80s for 75-125 dollars. Just be wary about purchasing aluminum tanks that are older than 1987. Many of these are made with a bad alloy (6351) and dive shops will not fill them. As a blanket rule, I wouldn't recommend purchasing any aluminum tanks that are older than 1990. A lot of dive shops are more wary about filling old aluminum tanks regardless of what alloy they are made from. Just be cautious about buying aluminum tanks on craigslist if you're looking for used tanks.

Steel tanks on the other hand can last indefinitely if properly cared for. I have steel tanks from 1963 that still pass inspection.

When choosing steel tanks, they sell high pressure (HP) and low pressure (LP) tanks. (Also have MP mid pressure but I won't get into that) Many people have their personal preferences but it doesn't matter too much. For example, a LP90 (low pressure 90) (~2400psi) still contains more air than an AL80 at ~3000psi. The volume of gas has nothing to do with the tank pressure. The only downside to HP tanks is that sometimes shops may have difficulties filling HP tanks properly to 3500psi. If a shop hot fills your tanks to 3500psi, they may cool down to 3100-3200psi so you won't be getting the full capacity of your tanks. I find that most shops are pretty good around here about slowly filling tanks as long as you're not in a hurry. The advantage of LP tanks would be that you'll usually always get a good fill as most shops can easily fill to 2500psi (and if you're lucky even more..). Some divers in practice will routinely overfill their LP tanks to get more capacity.

[nimoh]

I'll add a vote for steel. I have been diving my steel 100s for two years and have never regretted getting them.

One thing you might consider if getting two is to buy left and right pro valves, then they will be good for both DIN and Yoke, and will be ready for doubles.