Steel Tank - HP or LP????

[Brandnew2Scuba]

I am thinking I want to buy a steel tank as I am a cold water diver and could use the extra weight. I am wondering what the benefits are of both the HP and LP variety of steel tanks. As far as price Scubatoys has LP steel tanks for about $100 cheaper than the HP, that's one advantage to LP. It makes me wonder though what makes a HP tank worth more money. I'm far from rich but in buying a tank money is not an issue so let me know what you guys think. I've also ever dived rented aluminum 80's, is it worth the extra $ to go to a bigger size, say a 100, I'm only 5"8 and weigh about 175lbs. Any advice would be much appreciated.

 

[NorthernShrinkage]

One thing to consider is can your regular shop fill the HP tanks ( whats there max fill pressure ) I personaly prefer the HP but everywhere I have been is able to fill them to max pressure. In my opinion you can never have to much air .

 

[spectrum]

If you are a rugged hulk of a person then LP cylinders will cost less and be easier to get consistent fills for. They are heavier and remember that the rated pressure is with the + sign that may be lost at some future hydro likely decades away.

The HP cylinder will be lighter overall and leave you in better shape hor walking to shore dives and such.

As long as you stay with a steel tank that never becomes positively buoyant (I think they are all OK) you won't need to add extra weight just to sink the cylinder like with an AL80.

As for size it all depends on you and your diving. If you have good air consumption and dive with an 80CF crowd there there is no point in lugging a 120 around. If you seek deeper or longer dives then capacity rules.

We're a HP family, 4 80s and 2 100s

Pete

 

[chipwd]

The other thing to consider is what will your dive buddy(s) be using and how is their air consumption. I dive HP steel 100's (singles) and often will surface with a decent amount of air left when diving with others using AL 80's.

On the other hand, I am a little bit of an air hog still so if diving with a person with better air consumtion rates I can stay with them when they dive the AL 80's.

I guess I just went full circle but I use the HP steel 100's and like the weight they keep off my belt and the amount of air I have on hand.

 

[CompuDude]

I've said it before, I'll say it again. HP100 tanks are darn near the perfect tank.

They're shorter than an Al.80. They hold more than an Al.80, even on LP fills. They weigh the same or less. They have better buoyancy characteristics in most situations (esp. the cold water diving under consideration). And they have a longer expected lifespan. And thus a higher resale value.

You can never have too much air. And considering the tanks weigh the same or less than an Al.80 (on land), where is the downside? The only downside I can see is the initial purchase price...

 

[limeyx]

If you are a rugged hulk of a person then LP cylinders will cost less and be easier to get consistent fills for. They are heavier and remember that the rated pressure is with the + sign that may be lost at some future hydro likely decades away.

The HP cylinder will be lighter overall and leave you in better shape hor walking to shore dives and such.

As long as you stay with a steel tank that never becomes positively buoyant (I think they are all OK) you won't need to add extra weight just to sink the cylinder like with an AL80.

As for size it all depends on you and your diving. If you have good air consumption and dive with an 80CF crowd there there is no point in lugging a 120 around. If you seek deeper or longer dives then capacity rules.

We're a HP family, 4 80s and 2 100s

Pete

Remember that for (almost) every LP tank, for a little more $ you can usually get an HP version of the same tank, so saying "you get a better fill" on an LP tank doesn't really make sense -- yeah, the HP tank may not be as "Full" but you might well have more gas in it).

For example, say you get an LP95 and your dive store can only fill to 3000 psi.
Would you rather the LP95 @ 2640 psi = 95 cft of gas or:
HP-119 (more $ but same size) @3000 psi = approx 105 cft of gas
OK, the HP tank is not "full" but it has more gas than the LP tank.

Sure, if you get an HP-100 instead of the LP95 then the dynamics change, but the LP tanks are basically a subset of the equivalent HP tank (LP80==HP100, LP95==HP119, LP104==HP130)

Get a tank that matches the kind of dives you do, and yes, you do have to bear in mind what pressure your dive stores can fill to, and how far it is from your car to the dive site if you are shore diving.

 

[spectrum]

If you can't get a good HP fill then it's obviously not the tank to own in that neighborhood.

Other than that it's a cost and weight issue.

As a point of reference you can go to ScubaToys right now and take your pick of LP cylinders feom 80-120 CF, your choice $199.

A HP 100 there and now is $329. The difference is real money if you want a few, let alone if you are a couple getting started.

Meanwhile the LP 95 weighs 38 pounds empty where the HP 100 is only 33 pounds

The LP95 in question is 1 pound negative when empty where the HP100 is 2.5 pounds negative. That's 1-1/2 pounds that can come "off your belt" with the HP 100.

So that's the trade-off. The LP95 will save you about $ $129 but you will weigh 6.5 pounds more overall, not a bad deal.

Another consideration is fit and trim. A taller diver will usually benefit from the longer profile of the LP cylinders (or big HP models) where a stout diver may find delight in an HP80.

Pete

 

[PerroneFord]

I've said it before, I'll say it again. HP100 tanks are darn near the perfect tank.

Not for a lot of people.

They're shorter than an Al.80.

Problem. This means that those with SS Backplates are now going to be head-heavy. It is FAR easier to deal with a feet heavy condition than a head heavy one.

And they have a longer expected lifespan. And thus a higher resale value.

I don't know, I just VIPed some Al tanks produced in the early 80s. I'd say 20+ years on $135 (current price) is a pretty fair return on investment.

The only downside I can see is the initial purchase price...

Steel is more demanding. It is more susceptible to rust, pitting, bottom damage and sidewall damage. It's no panacea. For that, you get a tank can give a good service life, comes in more variety of sizes (particularly large sizes), and has some good buoyancy characterstics IF you need the weight.


There is no perfect tank. Have to go with what works for you.

 

[Brandnew2Scuba]

Thanks for the advice everyone.