steel LP vs HP

[jcollin160]

is there any advanatge to going to HP tanks? with a LP tank you could do a little overfill and get some more air but with a HP there is no way to do an overfill. most systems at dive shops will be lucky to do 3500 without taking all day. However i fill my tanks out of the cascade at the fire company, our system can go to 6000.

Just wanted some clarification why people are using HP.

 

[FlyinV]

I use HP since my LDS has no problem filling them and gets them a full load.
If my LDS couldn't fill them full I may have made a different choice.

I also like the fit and trim (and amount of air) I get from the HP100 tanks.

 

[jcollin160]

Isnt a 100cf tank a 100 cf tank whether its a LP or HP? is a hp100 smaller in size than a LP100?

 

[ScubaSteve]

I dive PST HP120's with a nice operating pressure of 3442 . I too love the extra air and the way it trims me out.

 

[fdog]

I use HP steels because they balance well, and are lightweight for their rated (not cave fills) capacity.

My LDS, and all the shops in the places we travel to, easily can fill up to 3450, so it's not a problem no matter what the mix.

OTOH, if you have lots of partial pressure blending in your future, especially with helium, then LP cylinders allow more use of the supply cylinder without spending the $ for a Haskel.


All the best, James

 

[mikemill]

Isnt a 100cf tank a 100 cf tank whether its a LP or HP? is a hp100 smaller in size than a LP100?

In the imperial system no. The CF of a tank is the volume of compressed air in the cylinder, not the size of the cylinder itself.

I use HP 119s because all the shops can fill it where I go.

 

[halocline]

Isnt a 100cf tank a 100 cf tank whether its a LP or HP? is a hp100 smaller in size than a LP100?

Sure, think about it. Higher pressure means more air in a smaller space. I don't think there are "LP100s" but the closest that comes to mind is the LP95 or LP108. Both of those are 8" in diameter, HP100s are 7.25", the LP108 is quite a bit heavier, the LP95 a little heavier, than HP100s.

Still, LP tanks are popular for a variety of reasons. One is that owners of them in some parts of the country routinely overfill them, really bumping up the capacity.

 

[fdog]

Isnt a 100cf tank a 100 cf tank whether its a LP or HP? is a hp100 smaller in size than a LP100?

You are absolutely correct, the contained volume is the same.

The cylinder size is different, though:



Worthington HP 100: 33 lbs, 24" long & 7.25" diameter

Worthington LP 108: 43 lbs, 26' long & 8" diameter

Faber LP 95: 37 lbs, 24" long & 8" diameter


All the best, James

 

[paddler3d]

Isnt a 100cf tank a 100 cf tank whether its a LP or HP? is a hp100 smaller in size than a LP100?

I do not believe so. A HP100 means you get 100cf of gas at the tanks rated pressure of 3442psi. A LP100 will give you 100cf at it's rated pressure. Your tanks will be different sizes. A HP100 will be physically smaller than a LP95.

Of course I can't find this now, but if I'm not mistaken, my HP130s are nearly the same in dimensions as LP104.

I'm sure other will correct me if I'm off.

 

[Gombessa]

Worthington HP 100: 33 lbs, 24" long & 7.25" diameter

Worthington LP 108: 43 lbs, 26' long & 8" diameter

Faber LP 95: 37 lbs, 24" long & 8" diameter

Yep (although that's one LONG LP 108 you've got there )! And some of us find it useful to compare HP v. LP in relation to their static volume rather than rated gas too:

Worthington LP 85: 34 lbs, 25" long & 7.25" diameter

Worthington HP 130: 43 lbs, 26" long & 8" diameter

Faber HP 117: 39 lbs, 25" long & 8" diameter

If you have access to overfills, the LP tanks are often cheaper equivalents of HP tanks of the same static volume. If you don't have access to overfills but like the feel/trim of a certain LP tank, chances are there's an HP tank that weighs and trims out very similarly, but gets you more gas at rated pressure.