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cpd123
06-04-2008, 11:33
I can't decide if I should get a low pressure 95 or a high pressure 100. Which is better? And which manufacturer should I buy from?

Rainer
06-04-2008, 11:37
There is no "right" answer.

Can you reliably get HP fills (I mean 3500psi once cooled)?

Can you get LPs overfilled?

Do you plan to transfill into this cylinder?

Do you plan to do your own PP mixing?

Are you comfortable with the extra weight of the LP? The extra width?

Worthington and PST are what I rock. HDG finish is what I look for.

BouzoukiJoe A.K.A. wrecker130 AKA Chuck Norris AKA joeforbroke (banned)
06-04-2008, 12:50
Definitely no "right" answer.

To make matters even more complicated, at least Faber has 2 different types of tanks that people might call HP tanks. The 3500psi versions are much heavier than the 3442psi versions, so you need to consider weighting issues (how much, distchable vs non-ditchable, etc) when choosing your tanks. A cold-water diver will probably prefer the heavier tank.

FWIW, I have FX120s (3442psi) and I often get short fills. When I learned to plan for them being 105s I became much happier. As a matter of principle, I'd rather underfill an HP tank than overfill an LP tank, though
there's something to be said for LP tanks if you can get over-fills.

Rainer
06-04-2008, 12:55
Oh, and then there's cost. My LP85s are (shhh) 100s (or sometimes 120s...) with the fills I get. I paid about $150 less compared to the equivalent capacity HP (per cylinder). That said, I also do have some (true) HP100s and HP130s.

Jack Hammer
06-04-2008, 13:27
I prefer HP tanks, but you'd have to compare different capacity tanks to see why. A LP95 overfilled to 3442 psi gets you ~123cf gas and has about the same physical dimensions as a HP120 tank. A HP120 filled to 2700psi gets you ~95cf gas. You can safely underfill a HP tank (that is about the same physical size, yet lighter) to get the same amount of gas a fully filled LP tank of similar dimensions gets you.

So if you plan on overfilling a LP for higher capacity, you should be comparing a LP80 to a HP100 and a LP95 to a HP120.

Jack

Rainer
06-04-2008, 13:37
I prefer HP tanks, but you'd have to compare different capacity tanks to see why. A LP95 overfilled to 3442 psi gets you ~123cf gas and has about the same physical dimensions as a HP120 tank. A HP120 filled to 2700psi gets you ~95cf gas. You can safely underfill a HP tank (that is about the same physical size, yet lighter) to get the same amount of gas a fully filled LP tank of similar dimensions gets you.

So if you plan on overfilling a LP for higher capacity, you should be comparing a LP80 to a HP100 and a LP95 to a HP120.

Jack

Um, sort of depends on what pressure you intend to overfill to, doesn't it? I usually push my LPs to 3000, but sometimes to 3600. The question should simply be to what pressure can you overfill (and what pressure do you want). For me, it's all about capacity, not pressure.

skdvr
06-04-2008, 14:47
I prefer HP tanks, but you'd have to compare different capacity tanks to see why. A LP95 overfilled to 3442 psi gets you ~123cf gas and has about the same physical dimensions as a HP120 tank. A HP120 filled to 2700psi gets you ~95cf gas. You can safely underfill a HP tank (that is about the same physical size, yet lighter) to get the same amount of gas a fully filled LP tank of similar dimensions gets you.

Jack

I agree with this. I have no problem getting HP fills at my LDS, so I have HP tanks. I would not want to keep pushing my luck or the luck of the Tank Filler for overfilling a LP tank. All though they have a pretty good track record in Fl where Overfilling LP tanks is fairly common. I still would rather fill a tank to its rated pressure. If I do not need a ton of gas I just tell the person filling my tanks to take them to about 3000 or 3100 and stop. When they cool down they are in the 2700 range which is still plenty of gas (HP 130 & 120's). If I want a full fill I usually leave them there for a few hours so that they can cool off. If I do not have a few hours and I want a pretty close to full fill they just fill them super slow. I personally would not buy a LP tank for my needs around here unless I got a great deal on one. I will stick with HP, but LP work better for some people...

With all that said I think that a HP 100 is a sweet tank.

Oh and I prefer Worthington tanks because of the Hot Dip Galvanized finish, which has also been mentioned by Rainer too. Great finish on the tanks. If I got a killer deal on some Faber (painted) tanks I would not pass them up espically because I dive fresh water, but I really like the worthington finish and buoyancy characteristics of worthington too. Some of the Fabers get positive when they are empty, which for the mainly cold water diving that I do would not be great for me...

Phil

Rainer
06-04-2008, 15:03
I would not want to keep pushing my luck or the luck of the Tank Filler for overfilling a LP tank. All though they have a pretty good track record in Fl where Overfilling LP tanks is fairly common.

Pretty good track record? Or do you mean perfect?

rab
06-04-2008, 17:27
The fill station (as others have said) makes all the difference. My tanks are 119ft2 at 3442psi, but I only get a true fill in Florida (where it often is 3600). In Ohio, I think the best I have ever received is about 3200-3300 -- operators just don't know what pressure to fill to in order to get 3442-ish when cooled. (or can't get to that pressure when the tank is warm/hot from the fill)

-Rob

Splitlip
06-04-2008, 18:09
I would not want to keep pushing my luck or the luck of the Tank Filler for overfilling a LP tank. All though they have a pretty good track record in Fl where Overfilling LP tanks is fairly common.

Pretty good track record? Or do you mean perfect?

I'm finding it a little more difficult to get LP tanks pumped up on the coast. Cave country may be a different story. I was always happy with 3000 in an LP. Recently bought some HP 100s. (Actually 3442). I am happy with them. Even filled to 3000 I am still ahead of the game.

david_57
06-04-2008, 18:20
Yeh I have double HP 100's Galvanise never any problems with fills and I was able to drop 8 lbs of my belt

fisheater
06-05-2008, 00:57
I don't have a problem with short fills on my Faber HP120.

I drop off my tank at the LDS on my way to lunch and pick it up after lunch. They know to fill it, let it cool and then top it off. I give them plenty of time to do it right and they always do.

If I'm diving where I need to get a fill during a SI, I get the fill done right away and let them know that I can wait a bit for the tank to cool.

skdvr
06-05-2008, 06:27
I would not want to keep pushing my luck or the luck of the Tank Filler for overfilling a LP tank. All though they have a pretty good track record in Fl where Overfilling LP tanks is fairly common.

Pretty good track record? Or do you mean perfect?

I dont know that I would say perfect. For one I am sure that they shorten life of the tank. Yes you are saving money buying them over the HP version so if you do not mind replacing them sooner that is fine with me. Obviously it depends on how much you are diving and how often they are being Cave Filled. I am also fairly certain (Not positive) that most of the catastrophic failers have happend in Fl and with pumped tanks. I have heard (or read) others talking about this same issue, so there is not much point to a discussion becuase if you think that pumping tanks is what you want to do then go for it. I for one will not do that...

Phil

Rainer
06-05-2008, 09:46
Please cite ONE catastrophic failure of an LP over-filled. ONE. And all the people I know over-filling (between 3000-3600) have had zero problems with hydros. This does assume that once filled, you actually go out and immediately dive the cylinders (i.e. you aren't keeping them pumped up like that for weeks). If my cylinders are going to wait, they only see 3000psi. Sorry, but your "fears" just aren't based on facts (or experience). Your "I heard it from a friend's neighbor's roommate's cousin" doesn't cut it. Try talking to some cavers.

cmburch
06-05-2008, 10:05
I like the HP100. It is a very nice easy to use size. The new tanks come with a valve for Yoke or DIN. Buoyancy empty is about the same for both tanks, but the LP95 is considerably heavier. The extra weight may make a difference if there is a long walk or hike involved in getting to the water. As for fills, it does not make sense to overfill an LP tank when an HP tank can be used instead. Here is a link for different fill pressures for the HP tank.

Worthington X-Series SCUBA Diving Tanks (http://www.diveriteexpress.com/gas/steel.shtml)

Look also at the HP120 and compare the size and weight to the LP95. If I think about comparing tanks, I look at cylinder weight and buoyancy empty first for comparison because I do a lot of hiking. Then I look at capacity - the HP tanks have the LP beat from above link. Then I look at length of the cylinder. The HP100 for me is the ideal SCUBA Tank. I use HP130s when I don't have far to walk.

Rainer
06-05-2008, 10:08
As for fills, it does not make sense to overfill an LP tank when an HP tank can be used instead.

Why? LP costs a lot less. Awhile ago (last year) you could find LP85s (basically the same size as HP100s) for $150 less than the HP100. If you get your 85s mildly over-filled to 3000psi then what have you saved by getting the HP cylinder? Answer, nothing. This of course assumes you can get slight over-fills.

There are also PLENTY of reasons why some people prefer LPs. Transfilling and PP blending are two such reasons. If you don't care about them, then HP might be for you.

Again, I have a mix of both (mostly HP actually).




The HP100 for me is the ideal SCUBA Tank.

It's a very good sized cylinder, I agree. What's right for you, though, might not be ideal for others. I'd suggest people first determine how much capacity they require, then have much weight, then what they hope to do with the cylinder. Hopefully those answers will help guide their search for their own ideal cylinder.

Rainer
06-05-2008, 10:33
LOL. I guess that's what you get when you only rely on the online medium to do your SCUBA learning. Too funny cburb.

caroln
06-05-2008, 12:11
I love doubled LP 85's. HP 100's are nice for singles, but for me as doubles, I'm extremely head heavy. With the 85's, I'm perfectly balanced. That's what I rent in FL, so I like to dive them at home so I'm super familiar with my cave setup. Cranked up to 3600 they have a ton of gas. Even at 3000, they have a very respectable amount of gas.

Jack Hammer
06-05-2008, 12:14
I prefer HP tanks, but you'd have to compare different capacity tanks to see why. A LP95 overfilled to 3442 psi gets you ~123cf gas and has about the same physical dimensions as a HP120 tank. A HP120 filled to 2700psi gets you ~95cf gas. You can safely underfill a HP tank (that is about the same physical size, yet lighter) to get the same amount of gas a fully filled LP tank of similar dimensions gets you.

So if you plan on overfilling a LP for higher capacity, you should be comparing a LP80 to a HP100 and a LP95 to a HP120.

Jack

Um, sort of depends on what pressure you intend to overfill to, doesn't it? I usually push my LPs to 3000, but sometimes to 3600. The question should simply be to what pressure can you overfill (and what pressure do you want). For me, it's all about capacity, not pressure.
Excellent point Rainer, as was the other about the cost of LP v HP tanks. I'm just trying to make the OP aware that they should be looking at more than just the cf capacity of a tank.

Anytime someone wants to buy a tank, especially if its their first tank, they need to look at many aspects of the tanks considered. I think the first should be the intended use of the tank vs how it'll likely actually be used. Then lots of other factors come in, such as the cf capacity, the physical dimensions & weight, HP v LP, cost, tanks buoancy haracteristics, availability of fills, ability to grow with it, physical size of diver, air comsumption rate, etc, etc

Jack

Rainer
06-05-2008, 12:20
Nice post, Jack.

CompuDude
06-05-2008, 12:57
For me, when looking at tanks, the first issue I look at is availability of overfills for LP tanks. Once that's determined, I know whether I should be focusing on HP tanks or LP tanks. Cost is important, but for a tank that should last over a decade, $35 really shouldn't be the deal breaker.

Once I decide on HP vs. LP, the next thing is to figure out how much gas you actually need, so you know which size tank to be shopping for.

LP85s and HP100s are practically the same tank, although the LP85s are a smidge cheaper. They're not as dramatically cheaper as they used to be. ($310 (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=LP_85_Steel_Tank) vs. $345 (http://www.scubatoys.com/store/detail.asp?product_id=X7100))

But if I can't be guaranteed I will get at least 3100 psi, if not more, in my LP85 tank, I'm always going to be getting less gas than I will in my HP100 tank (assuming I make the LDS fill it to capacity, which they may grump about if they're stingy with their compressor, but can't really say no to with a proper HP tank). If I'm ok getting smaller amounts of gas, that's one thing, but if I'm really looking for 100cf of gas (or close to it), having the LP tank is going to be problematic for me, and the HP tank is a better choice, even though they're otherwise nearly identical.

I know Rainer really likes the LP tanks, but I just see the HP tanks as being more reliable, from a filling standpoint, in the sense that you never have to worry about fills, no matter where you travel to, because you'll always get as much, as quite possibly a good bit more, than you will with the otherwise similarly-sized (exterior/weight) LP tank.

Rainer
06-05-2008, 13:01
Wow, prices really HAVE come up on the LP85s. They were $199 last year.

At $35 difference, IF transfilling and PP blending are not concerns (we do both extensively ourselves here in MA), then the HP100s now would appear to be the better deal (assuming you aren't somewhere where compressors top out at 3000).

cummings66
06-05-2008, 15:37
I have doubled HP100's and HP120's. LP cylinders do not normally get an overfill in my neck of the woods so LP cylinders don't make as much sense for me. I would have bought a couple LP85's but the deal fell through.

cpd123
06-05-2008, 19:11
Wow, thanks for all of the responses. I think I'm going to go with the LP 95, mainly because the closest filll station near my place can't go much over 3000 psi. Thanks