Tank question

[riplipper]

Looking to purchase tanks....when I go online to research there must be 50 different tanks...aluminum...steel and a milion sizes....
Dont most people use aluminum 80's, arent they pretty much the standard.....or am I way out of the loop....anyone use steel...

[Red]

I like my steel 95 lp's they work the best for me. And I think the (faber's) are the best.

[Nikki]

Most recreational divers use AL 80s. If that's not enough air for you, try AL 100s if you have a yoke valve on your regulator set-up. If you want to upgrade, you can get a DIN valve on your regulator and go with Steel 100 or 120s.

[Rice]

For spearfishing you might need more air than an aluminum 80. I find that Aluminum 80 are great for looking at coral and touring around zen like.
When I'm killing fish I need extra air.

I just picked up a pair of PST steel E7 119 cu foot tanks. A couple of my spearing buddies also have them. They cost more but are worth it.
I don't need a weight belt when diving them, The bouyancy swing is better(they don't go negative at th end os a dive) And mostly It's a lot of air on my back.
Oh, and PST tanks are hot dip galvanized so they are much less prone to rusing than other kinds of tanks.

Steel tanks are also known to last 30-40+ years.
good shootin,
Rice

[Thunderball]

Actually, the PST 199 is designated E8-119. The older E7 is actually a 120. The big difference is in the tank dimensions. If you are tall, and like a tall, skinny tank, then go with the E7-120 (7.25" diam, 28.25" height, weight empty 38#). I am 6'1" and love my E8-119 (8" diam, 24" height, weight empty 41#). I like my tanks as short as possible.

These are low pressure tanks that are filled to 3442psi. The tank size is essentially the old PST 95, just cranked up in pressure to deliver the added volume.

I have four of these tanks and have been very happy with their weight and capacity. You can never have too much air, especially when hunting. As stated in another post, their weight allows you to remove some weight from your B.C.

I would say that the three things that have really changed my diving in the last 5 years are: a dive computer, enriched air, and a larger tank. Hope this helps.

p.s. you can get more info about these tanks and how to purshcase them at www.diveriteexpress.com/gas/steel.shtml or by going to the Pressed Steel website.

[Rice]

You're right Thunderball, I have E8-119s. I chose them over the E7 120s because the wider tank is more stable in a rocking boat and easier to sit down in.
thanks,
Rice

[Chad Carney]

Aluminum 80 = low volume, poor valve design, too tall and high buoyancy...what do expect for a low price?

Just give me a steel HP100, the perfect balance of capacity, quality, length, diameter, and ballast!

Or a steel HP120 if it's real deep.

Chad

[StoneFish]

I like the PST 119s too , but if they are more $$$ than you can afford get the PST 80 . More air than a aluminum 80 and better buoyancy characteristics .

[WonderBoy]

Chad,
Just curious....what's your beef against the Sherwood 5000 valve design?

[from the sea]

din is better
so are steel hp tanks
i like the lp 120 steel oms tanks
and al tanks get real floaty when almost enpty, like haveing a pair of floaty wings

[Mobius1]

yea i was using steel 100's today on a dive boat and i noticed that i felt a lot more comfortabale with them. but meh im too cheap for steel i am just a poor Hs student heh

[Thunderball]

We were all poor HS students once upon a time. I bought my first steel tanks from a dive shop - used. They were only 3 years old (steel 72's). He used them in his classes and they were in great shape. You don't have to buy a new PST tank, just go to your local dive shops and see if they have any used steel 95, or 100's to purchase. Just a suggestion.


BTW - PST have excellent valves on them. You can switch between DIN and Yoke at your leisure by simplyl screwing the adapter in/out of the valve. This is espceially important if you are going to crank the tank (3442psi) above 3500psi (technically now a HP tank), which I sometimes do. It's a strange feeling when you make a really long dive, and still come back with 1500PSI in your tank! Sweet.

[Spear One]

HP steel 100 w/din valve if most of your dives are 45 to 80ft.
HP steel 120 w/din valve if most of your dives are 70 feet or deeper.

[Chad Carney]

Originally posted by WonderBoy
Chad,
Just curious....what's your beef against the Sherwood 5000 valve design?

I never singled out any brand of valve. (Sherwood has made some of the best valves of any on the market.)

It's just my opinion that the face O-ring design is a poor sealing system for todays tanks and regulators. Especially the skinny O-ring type that has been in use on aluminum tanks since they first came out. O-ring extrusion is a constant problem even when filled to just 3000 or 3200 psi.

My first tanks were also 71.2 steels and at least they used the fat O-ring and were less likely to extrude.

DIN is definitely the better way to go. I bought steel 100s in 1988, the first year they came out,. They were called Genesis tanks and only Sherwood had them.

I've never owned an aluminum tank above 30 cubic feet.
Besides my previous beefs with them, I'll add neck cracking, paint peeling and neck fizzing from accelerated corrosion due to extreme dissimilar metals.

Chad

[Mobius1]

I bought a old al 80 tank for 30 at agarage sale.
it needed a hydro but hec k the thing was fine inside
the thing had been around since um...1978 is the first hydro stamp

It just needed a new valve because it had a plastic dipstick.

[WreckDiver]

HP100 & HP120 with DIN thermo Valves is the combo I use no weight belt needed - almost perfectly nuetral at the end of my dives.

[riplipper]

wow, thanks for all the information....I have been a recreational diver for about 12 years...about 300 dives all the carrib or south florida...now live in jax and looking to dive and kill fish....so I have a lot to learn ....thanks again....

[Spearette]

One last contribution... let me echo all the great comments about steel tanks. I've been diving with Genesis steel 100's for about 10 years now, and you couldn't pry them out of my hands. On the rare occasions I am stuck with aluminum 80's I am reminded everytime of why I gave them up. It's all the same reasons mentioned previously.... my 100's give me more air, better bouyancy, better connection (DIN) to my first stage, and they are the same size as alum 80's. Gotta pay attention when getting them filled, though. Some shops are clueless, and will only give you 3000 PSI, instead of the rated 3500 PSI, if you don't check behind them. Maintenance is very important on steel tanks also. If you have to empty your tanks before refilling (some shops can't mix on top of existing air), make sure you do it very slowing to prevent internal condensation. Steel is more prone to flash rust which can be created by a combination of moisture inside and filling with O2 first. The good news is that flash rust can often be handled by "tumbling" - steel ball bearings are put inside the tank, and it's tumbled until the rust is eliminated. I actually lucked out on the ones I have... they were given to me by a dive shop who no longer wanted them. Best of luck and happy hunting.

Jan

[Chad Carney]

Even when short filled a steel HP 100 will have more gas than an aluminum 80 tank. Approx. psi/vol chart below. (The new E-7 100 is almost the same exact tank.)

PSI - Cu ft
3700 - 106
3600 - 103
3500 - 100
3150 - 90
3000 - 85
2700 - 77.5

An alum. 80 at 3000 psi is only 77.5 cu ft. and is 2 inches taller than the 100.

Steel 120s also have a proportionate volume advantage as well.

Only the steel 80 will end up with less gas than an aluminum 80 when short filled. It needs the full 3500 psi to have 80 cu ft.

Steel tanks don't require eddy current testing or extensive visual neck observation, in fact the machines don't work on them.

The oddest thing once happened at the dive store I managed and it showed physics characteristics I would not have thought possible. A huge bank tank blew off a stainless steel fitting and the tank began blowing nearly 4000psi through the small internal tube opening, maybe 3/16". The tube began to sweat of course and ice up, slowing the flow of air. What I did not expect, that the owner told me would occur, was that the ice sealed it completely! Then it thawed and began blowing again. This went on all day, over and over, until it was empty and the fitting could be repaired.

Moisture is removed and the air is extensively filtered when a scuba tank is being properly filled. The cylinder will only sweat on the outside when it is drained. It is a common misconception that it also condenses on the inside. When tanks are observed with water inside it's usually due to blowing moisture into them, either at the valve connection due to residual water in the valve opening, filler hoses dropped in the water bath, or from poor air quality in the first place. These are the fault of the air station. It can also be the divers fault if he empties them in the water or leaves them empty for long periods of time.

Obviously they should be drained slowly, (just like they should be filled slowly), which prevents the rapid cooling, icing, blowing over, and all that noise. When safeties would blow in the shop sometimes it would knock fluorescent lights out of the fixtures, or set off the security alarms. When they blew in te fill tank somebody got seriously baptised!

Chad

[Codbone]

I have been trying to find hp 100s. Nobody has them. At least at a resonable price. Any advice? I am located in Palm Harbor. The prices I have been getting from those who dont have them is 305.00 to 320.00 with yoke valves.

[Spear One]

I didn't think they put yokes on HP tanks. Am I wrong about this? Aren't HP tanks rated to 3500 psi and therefore you must use Din valves?

[bgbill]

Originally posted by Spear One
I didn't think they put yokes on HP tanks. Am I wrong about this? Aren't HP tanks rated to 3500 psi and therefore you must use Din valves?

Kevin,

I think they are talking about the new PST E7 series tanks, which are rated for 3442psi, and come witha 200 bar din convertable valve.

[Chad Carney]

The E-7 tanks are 3442 psi and have a 230 bar DIN or Yoke valve.
The almost same tank was 3500 psi and could only have a 300 bar DIN valve for 16 years.

58 psi difference...I wonder who got paid off at the DOT and how much?

Chad

(But if it helps sell the tanks and brings the prices down finally, I'm all for it. Heaven help the divers using yokes on those pressures though.)

[tpabchbum]

Codbone, you can thank the Chinese for the price hike. I would buy them when you see them at $305.00-$320.00, they are only going up from there. Yes they are in short supply, PST will not be shipping steel tanks until possibly Spring of 2005, Faber tanks, from what I understand, should be in stores who had them on order sometime in the next few weeks, if not already, depending on the dealer. The only other alternative is LP tanks. They are a little bigger but also a little less expensive due to the fact that they are not in demand as much as HP. Also, you don't have to use DIN if you don't want. Another disadvantage of LP is they tend to be almost nuetral, not negetive, as they become empty.

[x-ring]

I love my new Faber 121. :)

[Capt.Gene]

The dealers who don't have the PST E7 100's can sell them real cheep. I'd like to borrow some of your money for a few months interest free also.
The price to actually take one home and dive it is $359 including boot and fill. Nitrox ready, decals and nitrox fill slight extra charge.

[Rice]

I just picked up a pair of 119s for $327 each. I didn't consider it a particularly great deal but average becuase of the shortage.

Rice

[Bahiano]

Loose the tanks...switch to freediving. That is where the rubber meets the ground ;) Its cheap and efficient way to kill fish.

[HeadHunter]

Take a look at the faber 81's....89 cf at 3000 psi. These are steel tanks, they come with a combo valve, either yoke or lp Din. Rich at simply scuba has them in stock for $199.00. I've never dove a tank this size that "felt better" in the water. Check them out on fabers website. I bought 8 of them and have used them for doubles, big gas stage tanks and solo's. A good sized steel din tank for not much more $$ than an aluminum 80!