Which brand of steel cylinder / tank should I buy?

[WetDane]

Hey Ralph,
I hear you - I can't really speak from experience here either as I don't have HP myself - it's just what I have heard from some people out here...

Dane

 

[Thomas Ivey]

Originally posted by scubakat

Originally posted by Thomas Ivey
The HP-80 at 2640 psi holds 64.5 cf.
ti

Thanks TI, that's all I needed to know to know that I don't want an HP tank.

So now it's dumb question time. How do you do the math to calculate that? I get just wacked trying to do the unit conversions...

I have been diving the PST LP-80's (rentals) I like them very much. I think I want just a little more air though. Can you paint the PST's?

-kate
[/B]

Well, the HP design has tremendous advantages over other tank design especially in length and weight, but if you cannot get the fill of 3500 psi, the tank will not do you much good. There are some areas on the East coast that do not have the capability to fill to 3500 psi.

Capacity Formula:
Compressibility factor for air @2640 psi is 177.4 and 3500 psi is 226.1 both factors are set for 70 degrees.
You need to know how many cu.in. of water the tank holds. We will use our HP-100 (780cu.in) for an example:

(780)(226.1)
1728 = 102 cf @ 3500 psi

(780)(177.4)
1728 = 80 cf @ 2640 psi


You could paint our tank but I think the paint will cause you more problems down the road. The paint will scratch off, and we see where paint will trap water between the
paint and the tank and cause excessive corrosion. My suggestion if you what color on your tank, put a color tank net or tank sleeve.

ti

 

[Tavi]

Thomas,
Thank you for your reply. I definately want the PST tanks, I thought that they were made for Genesis by PST. I'm glad to know that there is another that I Don't want.

Scubakat,
Leisure-Pro carries both the Genesis and the PST Tanks.

Tavi

 

[Warhammer]

Thomas,

Where might I get my hands on the complete and exact specs for Pressed Steel tanks, including the water volume? I've seen them published on numorous sites, but I don't believe I seen the water volume specs.

 

[Thomas Ivey]

Originally posted by Warhammer
Thomas,

Where might I get my hands on the complete and exact specs for Pressed Steel tanks, including the water volume? I've seen them published on numorous sites, but I don't believe I seen the water volume specs.

send a request to tivey@pressedsteel.com and I will send you our most current data.

ti

 

[rcohn]

Thomas,

Isn't there a correction for non-ideal gas behavior (Van der Waals) in PST HP tank volumes? In other words is the rated capacity (100 cf, etc.) based on real or ideal gases?

Ralph

 

[Warhammer]

Done deal, thanks Thomas.

 

[Thomas Ivey]

Originally posted by rcohn
Thomas,

Isn't there a correction for non-ideal gas behavior (Van der Waals) in PST HP tank volumes? In other words is the rated capacity (100 cf, etc.) based on real or ideal gases?

Ralph

The volumes that we use are based on "actual for real gases" related to breathing air. We do not have any varibles in our equation that are not "real".

Van der Waals is based on hypothetical for ideal gas, all real gases do not follow the ideal gas law for volume when compressed.

ti

 

[King_Neptune]

I originally got 3 emails about this post and this other long thread saying that they kind of hand enough already so I closed the thread, it was nothing personal Military Diver.

But then .... In the following 24hrs since, we got no less than 317 emails saying that they thought we should leave it open as it is still very informative. I'll refrain from repeating the rest of what they all said and leave it at that, hehe.

So, the people win, unlocked they are ...


=-)

 

[jobowker]

I think 7 pages ago, the original question was 'what brand of steel tank'. There were one or two responses mentioning this, but I didn't see the answer to the differences in buoyancy characteristics in Faber vs. PST.