LP vrs HP Tanks

[elmer fudd]

The point I was trying to make about the high costs of a lot of scuba gear was that most of the time, any performance difference that people get from buying high end gear are minor, come at great cost and despite that a lot of people don't seem to mind paying for it. HP tanks on the other hand have a large and obvious advantage over similar dimension LP tanks and generally at a cost of about $100 extra per tank. For example an LP95 vs. an HP119. I can't think of many other scuba products where so little extra money buys you so much extra performance.

 

[spectrum]

The appeal is (and then i'll leave this dead horse alone) that a HP120 holds 120cu' of air. No one is going to overfill an HP120 60%. However, an LP120 holds 120cu' of air at 2640psi or 181cu' of air at 4000psi. And people regularly overfill a LP 60%.

It's not comparing apples to apples. It's not even comparing apples to another peice of fruit. IF you dive where I dive, LP holds alot more air. If you can get 3600'ish fills, your argument is exactly opposite of reality.

The chink in that position is in your phrase, "IF you dive where I dive". To most divers in most regions this just isn't reality.

I'm as much of a HP junkie as the next owner but in favor of LP I'll add:

For the taller fit diver the LP cylinder will be longer and trim out nicely. That makes it a nicer choice to dive a given capacity, while being cheaper and easier to get filled. In many dive gear items fit is everything. However on cylinders sometimes it's all about the numbers $$/CF. The fit perspective really does have a place in cylinder selection.

Pete

 

[spectrum]

The point I was trying to make about the high costs of a lot of scuba gear was that most of the time, any performance difference that people get from buying high end gear are minor, come at great cost and despite that a lot of people don't seem to mind paying for it. HP tanks on the other hand have a large and obvious advantage over similar dimension LP tanks and generally at a cost of about $100 extra per tank. For example an LP95 vs. an HP119. I can't think of many other scuba products where so little extra money buys you so much extra performance.

I agree that a lot of divers have an almost demeaning attitude towards their cylinders compared to other pieces of gear. "It's just a tank", goes the saying.

First of all they don't have the bling of many other items so I'm sure that's some of it. I think the fact that many of us own/need/use a collection of them also motivates us to limit the expenditure per cylinder. I've done well to get 7 of 12 used, that helps a lot. The rest were great buys when purchased.

Pete

 

[nielsent]

I must agree wholeheartedly with Spectrum here, one of the reasons that I like the LP120's so much is that I am 6'2" tall, and overall a big guy. The Cylinders might be a bit bulky, but they are a great fit on my back. I have never had a trim issue with them, unlike other doubles I have used. I never thought that diving with twin boilers on my back would feel so comfortable.

The cost is always an issue as well, I paid 300.00 for the tanks, bands and manifold. An older buddy of mine wasn't even able to lift them anymore.

 

[NAM001]

I think they maybe talking more about people like me that buy $200. wet suits and regulators off e-bay. We also couldn't conceive of spending $2500 for a scooter:shocked2:. I didn't pay that much for my car! I have been saving money for a drysuit. I'm hoping by the fall I'll be able to buy one. Fifteen hundred dollars for me at least is hard to come by. Also HP requires regulators that can handle HP. I'm told for my regs its a $150.00 upgrade more than I paid for the regs. So I just bought a used LP104 for cheap.

I do like the discussion as I was thinking about the size v weight v gas volume difference this thread as helped a lot. Thanks all.

for me i got them for the lp aspect of it.
i always get a full fill. the lds only pumps to 3200
my compresor does not have to work so hard to fill.
the faber is a little heavier but i need only a little lead

 

[lamont]

for me i got them for the lp aspect of it.
i always get a full fill. the lds only pumps to 3200
my compresor does not have to work so hard to fill.
the faber is a little heavier but i need only a little lead

you are fixating on feeling like you get ripped off on a 3200 psi fill in an HP tank.

i'll take a 3200 psi "short fill" in an HP130 over a 2640 psi fill in an LP104 anyday.

again, i compare by the size and water volume of the tank so HP130s and LP104s are apples-to-apples. they're going to feel nearly identical on my back. having a higher service pressure is going to always be better -- all other things equal -- even though you may not have a compressor that can hit it.

the imperial way of marking tanks according to their capacity at service pressure, and not their water volume, confuses people and makes them think that LP104s and HP100s are more of an apples-to-apples comparison, when they aren't.

 

[FritzCat66]

I agree that a lot of divers have an almost demeaning attitude towards their cylinders compared to other pieces of gear. "It's just a tank", goes the saying.

Oh man, I am so opposite of that! If I had to, I would swap out or trade in all my gear EXCEPT my HP120's. They fit me right, I trim out great with them, they've got enough volume that most of my dives are deco-limited and not gas... just perfect for me. My single best purchase!

Second would be my Cressi mask... not because it's anything fancy or expensive, but simply because I tried on dozens and they're the ones that just plain fit my face.

 

[NAM001]

you are fixating on feeling like you get ripped off on a 3200 psi fill in an HP tank.

i'll take a 3200 psi "short fill" in an HP130 over a 2640 psi fill in an LP104 anyday.

again, i compare by the size and water volume of the tank so HP130s and LP104s are apples-to-apples. they're going to feel nearly identical on my back. having a higher service pressure is going to always be better -- all other things equal -- even though you may not have a compressor that can hit it.

the imperial way of marking tanks according to their capacity at service pressure, and not their water volume, confuses people and makes them think that LP104s and HP100s are more of an apples-to-apples comparison, when they aren't.

I UNDERSTAND EXACTALLY WHAT YOU ARE SAYING. woops i am not dissagreeing with you. and i am not fixating either. my lds only pumps to 3200. many boats and shops pump to 3200. some shops charge extra for over 3000 or over 80cuft. for those shops that set thier compressor shut off to not allow fills over 3000 the 3400 tanks are a waste of time. it forces you to go to larger tanks such as 100's or lsarger to get the 80 or so cu ft you want to have after the tank cools, as not to run short on the al80's your buddies are using. i personally had no use for large tanks in shallow lakes to have a need for 120-130's at the time i bought my tanks. the cost, air availability and capacity put together were the reasons i used the lp's. that's not to say they should be ideal for everyone, just for me. by no means am i saying that i am being short changed with a 3000 fill on an lp tank. my rix fills my 95 faster than an al80 because of the lp. ii probably get 7 cu ft /min from my rix. only pumpimg to 2500 gives me plenty of gas and is less wear on the rix. i often fill al's to 2500 and not the 3000 for lake diving cause we just dont need the full 3000. i have actuall considered getting some hp steels for a doudbles set up for the reasons you have cited but for other than being able to say i have dove doubles i cant justify it. I just use a 120 lp pumped to 3000 if i need that myuch air. i know there is more to doubles than just air. i carry a pony for that. and i dont go to those places where doubles are the ideal setup. the dir extereemism is not needed for the divng i do.

regards

 

[elmer fudd]

Here's the thing though, an HP119 has virtually the same dimensions as your LP95 and holds the same amount of air at the same pressures. As far as size and trim goes you'd be hard pressed to tell the difference and the weight only varies a couple of pounds. The only significant differences are the 119 is rated for about 1000 PSI more, costs an additional $100 and can hold an additional 24 cf of air when filled to capacity.

 

[David_57]

HP 100's work fine for me have never had a problem finding a dive shop that can fill them to their full rating at 3442 PSI usually they pump them up to 3800 PSI warm cool they are almost exactly 3500 PSI, the people that fill them have this to an art. Doubled up that's plenty of gas for the types of diving I do added to this the buoyancy characteristics -10 full and -2.5 empty its my bottle of choice. When I was in Scapa Flow I rented doubled up 120's way to heavy especially after a long cold dive took a lot of effort for me to haul them back to my place on the boat even tougher when I shore dove the Blockships fell in knee deep water took all the strength I could muster to stand back up.