Aluminum Vs. Steel and some other questions

[StreetDoctor]

Right now I dive with an aluminum 80. I'm looking to switch to a bigger tank to get some longer bottom times. What are the benefits of going high pressure over low pressure if any? I'm assuming the HP100 tank is quite a bit smaller than a LP95? Another important piece of info I need is the diameter of the tanks. I get free fills at my firehouse but the tank has to fit in the compressor tubes. I'd also like to use doubles in the future so I think either of these tanks would be fine. (I'm 6'1" 200lb) My setup right now is an alum 80 with a BP/W with a SS plate and 14lbs of weight. I figure if I go to a LP95 or a HP100 I can drop 4-5lbs out of my weight belt, is this correct? Anything else I should know? Will I need a DIN setup? Anything I need to do to my regulator if I go high pressure?

 

[BKP]

You might want to read this... it'll get you started...

Dive Rite Express -- How to Select a SCUBA Tank

For the record, I ended up myself with HP100's... very pleased...
DIN is obviously a more reliable choice than yoke. However, that'll mean DIN 1st stage as well, which sometimes proves inconvenient if you travel and rent tanks domestically.

Most regs will handle the 3442 psi of the HP tanks...

 

[stairman]

I think the hp100 is a wiser choice for two reasons.You can get 3500 psi without an excuse for why they cant overfill an LP95.The 7 1/4 tank is less wobbley as a single than the 8 inch 95,and it is lighter which may not matter as a single.

 

[StreetDoctor]

excellent link thanks!

 

[1_T_Submariner]

The only down side to the Hp100 is when you get it filled to 3000 PSI it only contains about 87 cu/ft. If you can get 3442 then the Hp100 would be great. I have 2 HP119's so I get abotu 103-104 Cu/ft when filled to 3000 which I is comon.


The LP tanks you will almost always get the rated amount in them.

 

[rongoodman]

Both those tanks are 2" shorter than your AL80, at least the Worthington versions. With your height, they might put you head down. The Worthingtons come with the Thermo Pro valve, so you can use either yoke or DIN.

 

[DA Aquamaster]

Fills to 3442 psi are not an issue unless

You have a shop that believes:

1. All tanks are 3000 psi tanks and/or

2. A 3000 psi tank hot filled to 3300 psi is "overfilled" even though it cools to 3000 psi at room temperature (the definition of the service pressure).

Or unless you have a shop that has a compressor that will not go over 3300 psi.

In my experience, I get fills to 3600-3700 psi that cool to 3500-3600 psi on a regular basis in my 3442 psi tanks.

A 3300 psi fill will produce 95 cu ft in an HP 100, and realistically I have yet to find the shop that cannot achieve that pressure if they let the tank cool off and then top it off again.

 

[StreetDoctor]

Both those tanks are 2" shorter than your AL80, at least the Worthington versions. With your height, they might put you head down. The Worthingtons come with the Thermo Pro valve, so you can use either yoke or DIN.

That might not be bad, right now I carry 10lb on a belt and 4lb in a trim pocket on the cam band.

Am I right to assume I can take 4-5lbs off my belt if I go to a steel tank?

 

[StreetDoctor]

The only down side to the Hp100 is when you get it filled to 3000 PSI it only contains about 87 cu/ft. If you can get 3442 then the Hp100 would be great. I have 2 HP119's so I get abotu 103-104 Cu/ft when filled to 3000 which I is comon.


The LP tanks you will almost always get the rated amount in them.

Do you use the 119's as doubles? What do you think of them?

 

[BKP]

That might not be bad, right now I carry 10lb on a belt and 4lb in a trim pocket on the cam band.

Am I right to assume I can take 4-5lbs off my belt if I go to a steel tank?

Yes. (Going from an Al80 to an HP100)