LP vs HP decision

[Hoosier]

He said he'll be diving a dry suit...

So, what kind of dry suit, Trilaminate, Crussed Neoprene, or Neoprene? It is an important factor as well.

 

[Puffer Fish]

He said he'll be diving a dry suit...

Answer to ALL your problems: HP Steel 130 CF!!!

Indeed. And a short fill is still a lot of air...

Just the buoyancy of HP got me to get HP tanks... and the lighter weight.

I have 100's, 117's and finally the lovely 133...I don't understand today, why anyone would buy LP's...unless they were really, really low cost.

 

[The Chad]

LP's with cave fills like someone already said

 

[BSea]

If you are diving wet or dry. LP tanks are generally much more negatively bouyant than HPs.

Have you looked at worthington's tank specks. From what this shows, the LP tanks arn't more negatively bouyant, in fact they are less. Now that may not be true for the faber, I don't know about their characteristics

 

[ClamBake]

I just picked up two Worthington HP X7-120s a few weeks ago and absolutely LOVE them!! I'll be diving them both wet and dry and for me they are the perfect combination of volume, bouyancy and trim. I have no problem getting HP fills (I can see that as a concern if you don't have a reliable and convenient HP fill source) and the profile is not a problem for my 6'3" frame (I could see the additional weight and length of the 120s being a problem for the vertically challenged). The issue for me in choosing between HP and LP is that the yolk/DIN combo valve raised the question of whether to switch to a DIN. For now I have not as my Scubapro MK25 is rated for 3442 psi and I am planning a few trips in the coming months and didn't want the hassle (minor, I know) of switching between DIN and yolk or using a DIN to yolk adaptor. I may end up making the switch for cold water dives this winter.

 

[Rob9000]

Thanks everyone for your input. It is a trilam dry suit I have. When I started thinking about this, I was leaning towards a LP, but after reading more I am leaning towards a HP 120. The measurements of the 120 are closer to what seems like a good fit (smaller(7.25) diameter and longer) and the u/w characteristics of HP are similar to LP. Then, I can either get short fills and it will be a LP, or I can go DIN and get HP fills. According to the DiveRiteExpress site, a 2650 fill in a HP 120 gives you 96 cu.ft. I recently did 10 dives with a LP 95 and the volume seemed fine in terms of SAC needs.

I am also considering going DIN...I see you can bring a DIN adapter on trips to allow the DIN first stage to attach to a yoke.

 

[DiveGearExpress]

I have a HP 120, and 2 LP85s. Unless I let the HP cool for at least 30 minutes then have it topped off, I get a light fill. Usually in the 3200 range. But with my 85's, I get them somewhat overfilled, so I always end up with at least a full tank. Usually a little more.

With your HP 120 underfilled at 3200 you had 111 cf of gas.
With your LP 85 overfilled at 3200, you had 103 cf of gas.

The difference between HP and LP cylinders is the alloy they are made of. Other than that, the pysical charachteristics are damn near the same. An HP 119 becomes an LP 95 when underfilled. An HP 100 becomes an LP 85, etc. Do the math and you will see.

Our advice is get the HP cylinder. You can always underfill a HP cylinder, but not too many places anymore will overfill a LP one.

 

[nereas]

Indeed. And a short fill is still a lot of air...

Just the buoyancy of HP got me to get HP tanks... and the lighter weight.

I have 100's, 117's and finally the lovely 133...I don't understand today, why anyone would buy LP's...unless they were really, really low cost.

LP steel tanks still compete very well with HPs when scuba diving in outer space. Out there, everything is equally neutrally buoyant.

Other than that, HP is definitely the best way to go. Except, of course, for those divers who are really spaced out on old fashioned obsolete ways of doing things.

 

[LakeScubaDiver]

I'm 5'10" tall and weigh 155.....look at some vids (the ones that say "by LakeDiver") to see this monstrous beast of a tank (the 130) on my back!! Love it though and wouldn't go any other way!!

http://www.lakediver.com/videos.html

Click on the Broken Bow video and at about 7 min is a good shot of me...I have the two blinky red lights!

BUGG