LP or HP for doubles setup???

[H2Andy]

So it's not really significant at all.

it's been for me. i have very little gear, most of it bought used or on good specials, in order to be able to dive with good equipment

so ... a $200 difference is significant for me

but yeah, in the grand scheme of things, i guess it isn't for most people. and as i keep saying, diving outside of NE Fla is not an issue for me

 

[DA Aquamaster]

Where you live makes a difference as well.

A cave dive for you is a cheap fill, a short drive and a dive or two whenever you have a day off.

For me, it is a 12 hour drive each way, two days of leave for travel, a day of leave for each day there, and probably $200.00 in gas and a $100 a day in Florida plus fees. A dive "weekend" for me is two days of leave plus $600-$700 in expenses - which is oddly enough basically the cost of a good used set of doubles.

 

[Bowtie22]

I think after seeing all of the opinions and doing my own research I will most likely go with the HP 130's..... I really like the weight, size, and buoyance charteristics of them better than the other tanks....... I also like knowing that I can get a good legal fill on them wherever I go and I have plenty of gas (probably more than I would ever need on most of my dives).... I do wish that they were cheaper, but I have to agree with an earlier post "in the scheme of things an addtional $200 isn't much" (Until the other half finds out)....

 

[diveauz]

IF you go to PST's web site some of their LP tanks and HP tanks are actually the same...
old Part number LP 95 new part number HP 119

http://www.pstscuba.com/PST Scuba Product Specifications.pdf

 

[DA Aquamaster]

IF you go to PST's web site some of their LP tanks and HP tanks are actually the same...
old Part number LP 95 new part number HP 119

http://www.pstscuba.com/PST Scuba Product Specifications.pdf

Interesting chart. It makes the point that you'd still be better off with an E8-119 or E8-130 than an LP 95 or LP 104 given the legalities involved in filling them.

It also suggests that LP tanks are potentially becoming a thing of the past for all the size/weight/volume issues outlined above in this thread.

I still suspect the metallurgy is different. It would make sense to keep the same tooling and by default the same dimensions, but that does not mean that the same steel was used or that an old LP tank is identical to a new one - it just means they ain't making the old ones anymore as they have "new" ones.

 

[Papa_Bear]

Doesn't it depend on where you dive and what kind of diving your doing? On the California Coast and for Boat Diving you can't beat a LP95! Not a lot of Boats can pump much more than 3000psi and I don't care what they say! If your filling your own watch your electric bill for that last 500psi! It is hard on equipment and uses a lot of extra energy to get those last 500psi! I don't think the 95, 108, or 120 are on their way out at all! I Boat dive with LP95 or LP 120 and they're great! My all time favorite tank is the LP95!

 

[Luis H]

I still suspect the metallurgy is different. It would make sense to keep the same tooling and by default the same dimensions, but that does not mean that the same steel was used or that an old LP tank is identical to a new one - it just means they ain't making the old ones anymore as they have "new" ones.

It is very possible that they have just changed the heat treatment to increase the tensile strength on this type of steel alloy.

The most common alloy used in many steel tanks (ASTM 4130) is very sensitive to heat treatment and it is possible to control and change its tensile strength. To do that it would require a DOT special permit or exception since it is not covered by CFR49 par.178.37.

 

[diveauz]

the change in the tanks is not the metal but the standard that they are tested to.
LP95 is tested to DOT 3AA hydro 5/3 service pressure
HP119 aka E8-119 tested to DOT E9791 hydro 3/2 service pressure

 

[DA Aquamaster]

Doesn't it depend on where you dive and what kind of diving your doing? On the California Coast and for Boat Diving you can't beat a LP95! Not a lot of Boats can pump much more than 3000psi and I don't care what they say! If your filling your own watch your electric bill for that last 500psi! It is hard on equipment and uses a lot of extra energy to get those last 500psi! I don't think the 95, 108, or 120 are on their way out at all! I Boat dive with LP95 or LP 120 and they're great! My all time favorite tank is the LP95!

You are missing the point. just buy an HP-119 and fill it to 2640 psi and you have an LP 95 - but you have an LP 95 that you can still fill to 3442 psi iand 119 cu ft if the urge hits you.

 

[DA Aquamaster]

the change in the tanks is not the metal but the standard that they are tested to.
LP95 is tested to DOT 3AA hydro 5/3 service pressure
HP119 aka E8-119 tested to DOT E9791 hydro 3/2 service pressure

That is indeed one of the differences in the certification standard and test protocols.

But do you have a primary source stating the same alloy and heat treatment is used in both the old and new tanks?