switching tanks to steel

[all4scuba05]

Currently have 3 AL80's. Was wondering if switching to Steels is going to be worth it.
Want to drop some of my weights. Seams like it will only be about 4 pound drop. Is that correct?
Also, if the steels I get are "high pressure", what do I do about my Delta4 Reg? It's yoke style. Would low pressure be better choice?
Was hoping for a steel >80CF but at the same time was hoping for a tank that's shorter than my AL80's. Not going to happen? I'm 5'4" tall. Shorter tanks would be nice.
In a perfect world I would find steel tanks that are short, work with my yoke style regulator, don't weigh 50lbs out of water, allow me to drop half the weights in my pockets, and don't cost me $400. How can I get as close to this as possible?

 

[PerroneFord]

a LP95 is shorter than your tank. So is the HP119. In fact, the HP130 I believe is a bit shorter than the AL80. And you'll lose WAY more than 4 pounds with those tanks! I think the 130 is about 11 pounds negative versus the 3-4 pounds of the AL80.

Your regulator might be just fine. It should have its pressure rating stamped right on the yoke. But this is one reason many divers buy DIN to begin with.

Sounds like from our description, you're looking for a LP95. Not too expensive, shorter than AL80, can use with your current regs, will take some weight off your belt, and doesn't weight THAT much more than an AL80.

 

[Charlie99]

http://www.huronscuba.com/equipment/scubaCylinderSpecification.html is one of many websites that have compilations of tank specs.

I recommend that you look at PST E7-80 and E7-100 tanks. You can use all modern yoke regs with them, the E7-80 is shorter, lighter, and more negative than an AL80.

The E7-100 gives you more gas, is a couple inches shorter, but weighs a couple of pounds more than the AL80. It is however, 1 pound negative when empty, so you will be able to drop your lead by 4 to 5 pounds.

Both are 7.25" diameter tanks, the same as the AL80, unlike the LP95.

 

[Derek S]

I second Charlie's vote for E-7 100s. Excellent tanks. The E-7 80s are nice, but they are really short, so unless you happen to be a much shorter person, I'd definitely advise the 100s.

 

[lamont]

a LP95 is shorter than your tank. So is the HP119. In fact, the HP130 I believe is a bit shorter than the AL80. And you'll lose WAY more than 4 pounds with those tanks! I think the 130 is about 11 pounds negative versus the 3-4 pounds of the AL80.

you've got to compare dry weight. an empty Al80 is about +4, while a 130 is around 0.

if you're optimizing for taking weight off the weightbelt, the 119s/LP95s are a little more negative when empty (-1.5?).

and if you really want to take a lot off look at the faber HP100s which are substantially negative.

you can always add tank weights, or a weighted STA (in a BP/W) to move weight off the weightbelt as well (although i found a weighted STA pitched me head-down in steels initially -- now that i'm used to diving head-down with double steel tanks i find the weighted STA and single steels to prevent me from going feet down... funny....)

 

[BSea]

I have a HP-100 (E7-100) & love it. It has the convertable valve, and even though I now have a din regulator, I 1st used it with a yoke. Does your Delta 4 have a din conversion? If so, then that's the way I'd go. It's only about $65 to convert your reg, but then you'll probably want a yoke adapter to use when you go on trips. I like the 7.25 diameter tanks because then you don't have to adjust your straps on your bc if you use a rental. 4 or 5 pounds may not sould like allot, but you will be able to really tell the difference.

 

[spectrum]

Odds are your yoke is suitable for (HP) 3442 PSI as is, just ask or check your paperwork or look for markings. There's a boatload of threads about should you or should you not dive that way but it's commonly done.

As for going from AL80 to HP Steel here's my opinion:
http://home.gwi.net/~spectrum/scuba_al80.html

The math is slightly different for the 100s. If you'd be more comfortable with the same size tank and are not looking for the lightest possible rig the the 100s and very nice. I have some of each and they both work well for me (5'-9") There is a significant price premium above 80 CF.

Are you diving in a circle that gives you the need for 100 CF of air? Paying for the cylinders and lugging them just to end dives 1/2 full is pointless except for the adage," you can never have too much air".

Pete

 

[lamont]

As for going from AL80 to HP Steel here's my opinion:
http://home.gwi.net/~spectrum/scuba_al80.html

the rebuttal to the math you've got there is that the HP E7-80 may have much less than 77.4 cu ft of gas if its underfilled. worst case the fill operator fills to 3000 psi and the tanks cool to 2800 psi or something like that... but if you look at the same weight, then an X7-120 has a weight of 38# empty. this is heavier than the 33.6# of the Al80, but it is 6.4# less buoyant, so you have to add 33.6# + 6.4# = 40# -- so the X7-120 is actually 2# lighter than an Al80. or you can use an E7-100 which has 80 cu ft of gas at 2640 (same water volume as an LP80) and which is only 33# -- so its exactly the same heft of tank, but you'll be 7# lighter than an Al80 and have more gas capacity -- both at the same psi and particularly at rated capacity.

 

[Lead_carrier]

The heck with all the math calculations and junk. Borrow some different tanks, rent them or whatever. Dive a couple of dives with them and find out what feels best for you and go with it.