LP vrs HP Tanks

[FritzCat66]

To the OP - All good advice so far. One other thing that hasn't been mentioned yet: I noticed you're a fellow Floridian and if you're going to be diving a lot from boats, one other consideration is the tank diameter. For very shortsighted reasons, many boats are rigged with tank stands that only support the 7.25"-diameter tanks similar to a standard Aluminum 80. This makes diving with most LP tanks and some of the largest HP tanks a PITA on those boats. The highest capacity tank you can get in the smaller diameter is the HP120, as far as I know.

Of course, if you're mostly diving the springs or Venice beach... the boat factor won't matter!

 

[lamont]

I have two Fabers (LP 95 & HP 120). Are you suggesting they imported American steel for these tanks to Italy in order to make the DOT version?

Obviously, the source of the steel isn't as important as its composition. The steel could be mined anywhere in the world, then refined anywhere in the world, then shaped into tanks anywhere in the world, but the finished product is going to be of a similar composition (technically of similar properties, but I'll bet Faber and Worthington tanks are nearly identical in composition, and probably bought from one or two suppliers of that grade of steel worldwide). Faber is also unlikely to use the same grade of steel in their HP tanks as their LP tanks, since they can use cheaper steel in the LP tanks and cannot sell them at the same price as the HP tanks -- using HP steel in LP tanks would eat into their profit margin.

 

[onefastpony]

To the OP - All good advice so far. One other thing that hasn't been mentioned yet: I noticed you're a fellow Floridian and if you're going to be diving a lot from boats, one other consideration is the tank diameter. For very shortsighted reasons, many boats are rigged with tank stands that only support the 7.25"-diameter tanks similar to a standard Aluminum 80. This makes diving with most LP tanks and some of the largest HP tanks a PITA on those boats. The highest capacity tank you can get in the smaller diameter is the HP120, as far as I know.

Of course, if you're mostly diving the springs or Venice beach... the boat factor won't matter!

I use HP PST 130's which have an 8'' diameter and mainly do boat dives. Yes, most charter boats are set up for the 7.25'' tank, but they do have the ability to accomidate the big boy tanks. Some have the bungee cords that go over the valve, the ones that don't I just lay the tank down and secure with some weights. It is really not a big issue to me, especially for having the added gas.

 

[Scott L]

I use HP PST 130's which have an 8'' diameter and mainly do boat dives. Yes, most charter boats are set up for the 7.25'' tank, but they do have the ability to accomidate the big boy tanks. Some have the bungee cords that go over the valve, the ones that don't I just lay the tank down and secure with some weights. It is really not a big issue to me, especially for having the added gas.

They are not to fond of handling while full of gas I have found. Especially female crew...

 

[elmer fudd]

I really don't get the appeal of LP tanks myself. You can get HP tanks that closely match the dimensions of LP tanks. You can underfill the HP tanks if you want and use them as LP tanks. Likewise, you can just finish up your dives with 1200 psi instead of 600 psi. Me, I like more air. If I'm going to carry all that weight and bulk around I want it to hold as much air as possible.


In a hobby where people buy $700 regulator sets, $2500 scooters and $1500 drysuits, I really can't see the logic in skimping on your tanks. The performance difference between a $400 regulator and a $700 regulator is something a lot of us probably couldn't detect, but anybody can spot the difference 25 extra cubic feet of air makes.

I do have a couple of old LP72's though. Hard to argue with a $25 price.

 

[Scott L]

I really don't get the appeal of LP tanks myself. You can get HP tanks that closely match the dimensions of LP tanks. You can underfill the HP tanks if you want and use them as LP tanks. Likewise, you can just finish up your dives with 1200 psi instead of 600 psi. Me, I like more air. If I'm going to carry all that weight and bulk around I want it to hold as much air as possible.


In a hobby where people buy $700 regulator sets, $2500 scooters and $1500 drysuits, I really can't see the logic in skimping on your tanks. The performance difference between a $400 regulator and a $700 regulator is something a lot of us probably couldn't detect, but anybody can spot the difference 25 extra cubic feet of air makes.

I do have a couple of old LP72's though. Hard to argue with a $25 price.

I agree.. Nice piece by Dive Gear Express on tank selection...

How to Select a SCUBA Tank - Dive Gear Express

 

[Superlyte27]

I really don't get the appeal of LP tanks myself. You can get HP tanks that closely match the dimensions of LP tanks. You can underfill the HP tanks if you want and use them as LP tanks. Likewise, you can just finish up your dives with 1200 psi instead of 600 psi. Me, I like more air. If I'm going to carry all that weight and bulk around I want it to hold as much air as possible.


In a hobby where people buy $700 regulator sets, $2500 scooters and $1500 drysuits, I really can't see the logic in skimping on your tanks. The performance difference between a $400 regulator and a $700 regulator is something a lot of us probably couldn't detect, but anybody can spot the difference 25 extra cubic feet of air makes.

I do have a couple of old LP72's though. Hard to argue with a $25 price.

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.

 

[lamont]

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.

If you're not looking at money, the rational way to look at it is tank size:

LP104s are the same size as HP130s
LP96s are the same size as HP120s
LP95s are the same size as HP119s
LP80s are the same size as HP100s

What makes more sense, an LP104 or an HP130? An HP130 obviously makes more sense since you don't have to argue with putting a 3500 psi fill into the bottle.

In metric this would simple: all other things being equal, but money no object, do you want a 200 bar, 232 bar or 300 bar 15L tank? I'd take the 300 bar tank to get more gas for the same size tank.

The LP120 is a monster of a tank which has no HP equivalent, so if you really want to go big you need to go LP and overfill, but otherwise the HP tank of the same water volume makes more sense to buy.

It feels like you can "get away" with more and get "better fills" with an LP104, but I can dive one of those just like my HP130s (the differences in trim are subtle and just take getting used to) and I don't have to argue about getting 3500-3800 psi fills.

 

[elmer fudd]

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.

HP149. Holds 173 cf at 4000 with nearly identical dimensions to LP120's.

And I have no problem getting 3600 or even 4000 psi fills with HP tanks, but I don't know of anywhere in WA that would fill a LP tank to those pressures.

 

[AfterDark]

I really don't get the appeal of LP tanks myself. You can get HP tanks that closely match the dimensions of LP tanks. You can underfill the HP tanks if you want and use them as LP tanks. Likewise, you can just finish up your dives with 1200 psi instead of 600 psi. Me, I like more air. If I'm going to carry all that weight and bulk around I want it to hold as much air as possible.


In a hobby where people buy $700 regulator sets, $2500 scooters and $1500 drysuits, I really can't see the logic in skimping on your tanks. The performance difference between a $400 regulator and a $700 regulator is something a lot of us probably couldn't detect, but anybody can spot the difference 25 extra cubic feet of air makes.

I do have a couple of old LP72's though. Hard to argue with a $25 price.

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.