HP100 vs LP95 steel tanks

[Vampyre]

OK so lets talk tanks and the CF of gas they hold. After reading a bunch on tanks LP vs HP etc. I'm thinking that a LP95 might be a better option over a HP100.

Using this link Tank Volume If I where to get a HP100 steel that's rated to hold 100cf of gas 3440psi. I would need to have it filled every time to 3440psi to get the full 100cf out of it. Getting that high of fill every time might not happen all the time. So lets say I only got a fill to 2800-3000psi in the 100cf Hp. That would leave me with 82-88CF of gas in that tank!

Now a LP95 steel holds 95cf at 2640psi. Any over fill = more cf on that tank. Im pretty sure I could get at least 2600psi on every fill no matter where its filled. At least I would think/hope so. So unless I can get that HP100 filled every time to at least 3270 PSI which = 95cf, the LP95 would have the same amount of air if not more.

Please LMK if this makes 0 since or if I'm totally wrong. But right now it looks like a LP95 would be better buy then a HP100.

Im currently in the market for 2-3 steel tanks. I want to make sure im getting the best tanks for my use.

I do all sorts of cold water diving in MN. Deep, shallow, wreck, mine pits, local lakes etc.

 

[JBRES1]

For diving, I rather dive a HP100 rather than a LP95. The HP100 just trims out a little better for me. For getting a full fill the LP95 is a much better bet on it being filled.

If you are looking to get some steel tanks, try out both and see what you like better.


Jim Breslin

 

[Vampyre]

Ive tried out the hp100's and they seem pretty neutral. I did one dive in a lp88 or 85 last night and I felt a bit top heavy. But Ive only done one dive in the LP I borrowed. and about 6-8 in a hp100. So cant really compare them yet.

 

[halocline]

You've put your finger on one of the big issues with LP vs HP tanks, but fill stations seem to be getting better about HP fills. Another big issue between those tanks is size; the LP95 is an 8" tank and weighs a few pounds more.

 

[Lenaxia]

Something no one has mentioned is that some dive boats have issues with 8" diameter tanks. Depends on the boat.

I agree with JBRES1 though. HP100's trim out better for me.

 

[joe8mofo]

I dive LP95s most of the time and they are great when filled to 3200 psi. One can never have too much gas. Also I have experienced no issues with trim while diving them.

 

[Vampyre]

I talked to a few of the local shops around about HP fulls and they all seem to be able to do them correctly. The only time where I probably would not be able to get the 3400 is on a boat on superior. So If I can get the 3400 at least 80% of the time I think I'm leaning towards the Hp100's

 

[Orlando Eric]

The trick in getting good tank fills. Drop them off ahead of time and tell them you will be back tomorrow.. friday.. tuesday. Point out they are 3500 psi tanks and the Fill is $--- per full tank. I am willing to settle for a 3000 psi tank if you are willing to knock 17% off the price of the fill.

 

[TSandM]

Trim really shouldn't be an issue with single tanks, because you have the option of moving them up and down in the cambands. The only time it might really be a problem is with either VERY long tanks (like the 120s) or VERY short ones (like the HP80s). Anything else is going to be adjustable enough.

I find the HP100s and LP95s balance almost exactly the same, but the 100s are lighter, and I appreciate that when I'm hauling tanks on and off boats, or in and out of the truck. But we ended up doubling up our 100s, so I use the 95s as single tanks. (I don't like them as doubles AT ALL!)

 

[DA Aquamaster]

I use both LP 95s and X7-100s. In terms of trim, there is very little difference even with doubles.

Weight wise an X7-100 weighs 33 pounds compared to 38 pounds for a Faber LP 95 and 42 pounds for Worthington and PST LP 95s. The LP95s are 8" in diameter rather than 7.25" but are otherwise pretty similar in overall dimensions. In comparison, an X8-130 weighs 43 pounds, is 8" in diameter and is about an inch and a half taller than an LP 95.

In terms of fill pressures, my experience has been that getting a 3442 psi tank filled to 3400-3500 psi depends entirely on the shop but the odds are pretty good of getting 3400-3300 psi. In an X7-100, 3300 psi will get you 95.9 cu ft - basically the same as the 95.1 cu ft you get in an LP 95 at 2640 psi.

With LP95s, my experience has been three pronged. In cave country I get 3600 psi (129 cu ft of gas), in south Florida and North Carolina I get around 3000 psi (108 cu ft of gas) and in the rest of the country, I get 2400 to 2600 psi. Live aboards tend to stay close to the legal service pressure so don't expect an overfill on one, and some shops have no idea what a "+" means and will fill LP95s to only 2400 psi. 2400 psi in an LP 95 will be only 86.4 cu ft.

So...my thoughts are that the X7-100 offers a lot of gas for the size and weight and is a great off shore boat diving tank, especually when doubled as they are 10 pounds lighter than doubled Faber 95s, 18 pounds lighter than doubled Worthington 95s and 20 pounds lighter than doubled 130s. But double X7-100s are a little short on volume for cave diving if your buddies all have over filled LP 95s or 130s as a 3600 psi fill only gets you 104 cu ft compared to 129 cu ft.

Faber LP 95s are great tanks, especially in N FL where they get filled to 3600 psi and they offer a decent amount of gas if you can get 3000 psi. But they are heavier than an X7-100 in situaions where they have no more useable gas.

Worthington and PST LP 95 are less wonderful in that X8-130s weigh only 1 pound more and can be filled to 130 cu ft anywhere, making the X8-130 a much better choice.

Unless cave diving is in your future, I'd go with the X7-100s and if cave diving is in your future, along with deep wreck diving other places I'd go with the X8-130. As much as I like it, the LP 95 makes the most sense in cave country.