New Tank Question

[Teller]

I want to get a new tank but there is so much to choose from im not really sure what tank best fits me. I am diving an AL80 right now that I borrowed from my father. It does work fine and I guess I could get one just like it but looking around I have many options I never considered. Aluminum or steel, HP or LP, yoke or DIN. I have a DIN 1st stage with a yoke adapter so I could use a DIN valve but what is better about a DIN valve over a yoke. I also just started drysuit diving and would like to shed a few pounds so mabey a steel tank would be a good idea. If I got a HP tank could I get fills higher than 3000PSI? My LDS only had AL80 with yoke valves with the plug you can pull out to make it a DIN valve in stock. So when I asked him all these questions he kept pointing me in that direction. Not to say he is wrong but I am not sure if he was just trying to tell me what I wanted to hear or if he was telling me the truth. Any opinions?

 

[Bubbletrubble]

What volume tank do you need for the kind of diving that you do?
Can you get reliable HP fills (approx. 3500 psi)?
At some point in the future will you be interested in doing your own partial pressure blending?
What's your budget?

For open water recreational diving, there's nothing wrong with using a yoke tank valve. In my experience, the yoke connection has proved very reliable and in certain situations is easier to deal with than DIN. Fortunately, most new tanks come with the convertible DIN/K valve that has the nifty insert. Very convenient. If you're doing a lot of vacation diving, it might make more sense to leave your reg as yoke since most tank rentals in tropical locales have K valves.

 

[a22shady]

go with a steel tank. The will last longer as long as they are taken care. Also have better bouyancy characteristics. they are not as positive at the end of a dive as the Alum. Your choice is between HP or LP. LP is great because your almost always going to have a good fill. Neg of LP is they are generally heavier tanks. HP are great they are lighter but you may not always have a good fill. I personally Dive worthing XS scuba HP100. I like them compared to the others this was the lighter of the 100's made and better bouyancy for me.

 

[mpgunner]

Simple perspective, go toward steel. Gives you much better options.

 

[bigdave1969]

That is easy, go with steel, you will really like. And stay with the pro value that converts to din, if you get a 300 din value you can never use a yoke on that tank, with the pro value you can use either.

 

[Jim Baldwin]

What volume tank do you need for the kind of diving that you do?
Can you get reliable HP fills (approx. 3500 psi)?
At some point in the future will you be interested in doing your own partial pressure blending?
What's your budget?

For open water recreational diving, there's nothing wrong with using a yoke tank valve. In my experience, the yoke connection has proved very reliable and in certain situations is easier to deal with than DIN. Fortunately, most new tanks come with the convertible DIN/K valve that has the nifty insert. Very convenient. If you're doing a lot of vacation diving, it might make more sense to leave your reg as yoke since most tank rentals in tropical locales have K valves.

If you have a DIN reg take your DIN adapter with you on vacation and it's easy to dive the K valve tanks. Yes you might bump your head a little but it's not the end of the world.

With the steel tanks you can shed weight off your belt and you can pack more air. A low pressure 95 and HP 100 are going to give you 25 percent more air than the Al 80 you are diving with now. Plus you don't have a positive tank to deal with at the end of the dive.

I have HP PST 100 and 120's(3500) with the dedicated DIN valve. Excellent tanks but getting full fills can often present a problem. The shops in my area have compressors set around 3300 because they only fill Aluminum tanks. I'm the only person in a three dive shop area that uses steel tanks and the only person who uses DIN.

Using low pressure or the mid pressure tanks with the converible valves makes more sense. They're easy to fill and you should never have issues. Also if you take care of them your grandchilden can still be using them. My first set of doubles had original hydro dates from the 50's.

 

[rstofer]

Google for scuba tank characteristics and among other hits, you will get this:
http://www.huronscuba.com/equipment/scubaCylinderSpecification.html

Read and understand what you're looking at. Weight, buoyancy, capacity, diameter, length: all of these play into selecting a tank.

Larger tanks are good - if you need more air, go with steel.

Weight is bad - in general, HP tanks weigh less for the volume of air they contain.

LP steel tanks can be filled easily but they are HEAVY for the amount of air they contain. You have to hump the weight if you dive from a beach.

HP steel tanks are pretty common and I would expect to get complete fills if I left them at a dive shop. I would not expect to get complete fills on a charter boat. But an HP 100 at 3000 psi is still more air than a full Al 80 but not by much.

If you carry weight then exchanging it for tank weight is a good thing. If you don't carry weight (warm water divers), the negative characteristic of steel tanks is not a good thing. But you should still have ditchable weight. Exchanging all of your weight for a negative tank is not the way to go.

Luxfer rates their aluminum tanks for 100,000 fill cycles. That's about 137 years at two dives per day, 365 days per year. I seriously doubt that a steel tank will last that long. I would expect it to be a rusting hulk in 100 years or so. Yes, there are 50 year old steel tanks around. It won't be long until there are 50 year old aluminum tanks as well. It's just a fact that steel tanks were made first so naturally they have been around longer.

Steel tanks fail hydro too! And steel rusts!

Always get a DIN/K valve.

For cold water I use HP 100s. If I were able to dive in warm water (T shirt warm), I would use Al 80s.

Richard

 

[herman]

go with a steel tank. The will last longer as long as they are taken care. Also have better bouyancy characteristics. they are not as positive at the end of a dive as the Alum. Your choice is between HP or LP. LP is great because your almost always going to have a good fill. Neg of LP is they are generally heavier tanks. HP are great they are lighter but you may not always have a good fill. I personally Dive worthing XS scuba HP100. I like them compared to the others this was the lighter of the 100's made and better bouyancy for me.

I disagree, first off, the life cycle of an AL tank is way longer than any of us are going to live so deciding on which tanks based on the life of the tank is a mute point. Just look at the use and abuse that AL tanks take at resort locations. AL is more than up to the task.
Buoyancy characteristics while different may or may not be better for the diver. I for one can't...or more accurately will not use steel tanks when diving warm fresh water, which I do a lot of. Steels, even 72s, over weight me by several pounds and since I am not wearing any lead a lot of the time, I have none to shed. If the OP is going to continue using the AL-80 he already has access to then staying with the same type tank eliminates the need to change weighting between dives.
Then there is the cost issue. ALs are a good bit less expensive than steel, almost 2 for 1. A new diver needing more than one tank can get more for his money and even if it requires a little more lead, lead is cheap compaired to the cost of a tank.
Steel is a good option a lot of the time but not in every case.

 

[Teller]

i did consider a steel tank so I could loose some weight when using my drysuit but I only dive dry for about 4 months. I live in TX and dive a 3MM wetsuit most of the time. Im only using 10LBS with a 3MM and an AL80. If I get a steel tank and use it in the summer with my 3MM I might only have 4-5LBS to drop if I had to. Would that be a problem?

 

[redacted]

I have no problem getting HP fills in central TX and a Steel HP 100 is great for the Flower Gardens. However, in warm water you may have to take steps to not be too overweighted, like wearing more neoprene than you actually need. In your case, you should have no problem if you stick with your 3mm.