LP85 filled to 3600psi?

[tonka97]

I have not dove all HP cylinders but the ones I have dived, especially the HP 80 sizes, seem awfully negative and dive like I have a lead ingot on my head.


PST 95 2400 +10% 96.6 8 24.75 43.8 -3.3 -10.4

Faber 95 2400 +10% 95 8 23.8 37.2 -1.2 -8.325

OMS 85 2400 +10% 85 7 26 31 0 -6.7 .

N

Worthington HP x7-100 Buoyancy Empty: -2.5 Full: -10

I don't understand why the HP x7 100s would be considered awfully negative. They seem quite comparable. At the end of a dive they would have a reasonable degree of neg buoyancy.

 

[in_cavediver]

OK, first, I admit it. I do it with my 104's and my 85's. That's the first step to admitting you have a problem right? Oh yeah, I'll do it again this October so I guess I failed step 2.......

Now for the meat of it.

Is it safe? well, the record is pretty good but it does reduce the margin of safety. Its also illegal by DOT etc. That said, its such a small set of people doing this with no documented issues or liabilities, DOT has better things to worry about.

The LP and HP tanks are the same? - Pure BS. Each tank has a operating range of tensile strength and elasticity among other properties in their metallurgy. While HP tanks are higher on the tensile strength part of this scale, they also have a lower elasticity. That whole trade off thing you do in design creates different behavior in tanks and their reactions to stress.

Now, why so many LP tanks? Simple. I bought mine before the HP equivalents came out! Another good reason is characteristics of the tanks. LP85's are a sweet tank for smaller people and the price I got them for ($600 with bands and manifold), I couldn't even get a pair of HP100's.

 

[Skeeter1097]

I have 108 lp's and simply love them. I never pump them more thin 3200 as any more is a wast. I am a large man and with a 108 pumped to 3200 I dive with all my dive Buddy's diving AL 100 and hp 100's, plus some extra.
For a drift dive 60 to 100 ft I can get over a hr. bottom time. { That does not mean I am at a 100 ft for a hr.}
Yes you can pump them and we do. I see them at 3600 all the time and have seen them once or twice at 3900.

 

[xiSkiGuy]

I have not dove all HP cylinders but the ones I have dived, especially the HP 80 sizes, seem awfully negative and dive like I have a lead ingot on my head.

HP80s are very short tanks and most people that are average to tall in height will have trouble trimming them out.

Faber 100 3180 +10% 100 7.25 24.01 38.7 -7.26 -14.76

The 3180+ tanks are much more negative than the exemption series (E, X, FX) and not really representative of what most people are calling HP tanks these days.

 

[Nemrod]

Yep, all of that and that is why I gave y'all the link to that page so you could pick and choose what you like best. N