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RoyN
04-09-2008, 00:56
Hi,

I sold my three AL80N and wanting to move to steel for a long time.

I just asked my mom to order the HP100 and then one day saw the LP95.

Any differences in them other then the HP and LP? Its driving me nuts at the moment.

Should I go with two HP100 tanks? Please help! It is seriously driving me nuts. :smiley29:

terrillja
04-09-2008, 01:21
Check this out:
Worthington X-Series SCUBA Diving Tanks (http://diveriteexpress.com/gas/steel.shtml#capacity)

It talks about underfilling HP cylinders. LP is an option, but it all depends on whether or not your shop will overfill them.

cmburch
04-09-2008, 01:54
The HP100 is my favorite tank. The right size, weight, and buoyancy characteristics. The LP 95 is nice but it is slightly larger, 9lb heavier, and now similar buoyancy characteristics. For my purposes the HP100 is best, but for boat dives if no HP fill then maybe LP95 best. The amount of weight removed from belt compared to Al80 is about the same for both. I guess think about the 9lb difference and if only a 3000 psi fill available.

HP100 3000 PSI = 89CF
LP95 2640 PSI= 93.3CF
HP119 3000 PSI = 107CF

If you don't mind the extra 9lb, then it would make more sense to go HP119 over LP95 - similar size and weight.

The new HP's come with Provalve for both DIN and Yoke.

I have a couple of MONSTER HP130's, if you want to try them out, we can go to Pt. Lobos sometime.

CompuDude
04-09-2008, 02:15
I posted this earlier today on ScubaBoard:

~~~~~~

Drives me nuts to hear people saying they want to buy an LP tank since they can get "full fills" and not "short fills" in an HP tank.

You get what you get. Unless you're in cave country, the vast majority of shops are going to stop filling your LP tank at 2640 (or even 2400 if they notice the plus is gone!), while an HP tank, even with a terrible fill, will still generally get 3200 psi or so.

When you get 3200 psi in an HP tank, you can legitimately complain. If you get 3200 psi in an LP tank, you had better slink away without saying a word, else you risk getting someone in trouble.

Why on earth is better to pray for an overfill in an LP tank than accept an underfill in an HP tank, when both give you same amount of gas but one is perfectly legal?

There IS a small cost consideration. LP tanks are less expensive than HP tanks. But I was somewhat surprised to note, recently, that the difference is a LOT smaller than it used to be: In the neighborhood of $40, comparing LP95 prices to HP119 prices at one major online vendor. In my mind, that $40 buys the peace of mind that some fill monkey isn't going to cut me off at 95cf (or less, if no plus rating), based on my tank's rating. I may not get a full 119, but I'm sure as heck going to get more than 95cf... every time.

~~~~~

If you NEED the extra gas, and you can't get full (or even somewhat) HP fills, I can see a viable reason for going with an LP tank. But why would you want to lug around the extra size and weight if you're just looking for ~100cf of gas, and semi-reasonable fills are available?

HP100s are sweet tanks. My absolute favorites. Why do you want an LP tank?

As to the differences: 7.25" vs. 8". The larger tanks will have issues fitting in SOME boats. If you switch tanks, it's minorly annoying to have to reconfigure cam bands between the two sizes. The LP95 weighs a lot more. And in 5 years, you'll have to hope you can (a) find the right testing facility and (b) the right testing facility can and will do a "plus" hydro test on your tanks, otherwise technically you lose the plus rating and your LP95, which technically has a working pressure of 2400psi but is allow 10% overfill to 2640 to deliver 95 cf, is now technically only allowed to be filled to 2400 psi and thus only holds 86 cf of gas. (see overfilling discussion above, again) Now you're that much farther behind a simple HP100, assuming no overfills. And yes, it still weighs 9 lbs more.

cummings66
04-09-2008, 07:30
That's the issue as you surmised. In my PSI cylinder inspection course they said Florida was a bad influence on the rest of the country. Overfills are a bad practice, it's been in being so long now that the whys and hows of it starting have been forgotten by many. The claim is it was by a cylinder manufacturer (Faber) that said basically our cylinders are good for 100,000 fills, or 10,000 fills to test pressure. That gave the go a head for overfills to those looking for a legit reason to do it.

If you believe Faber then a LP cylinder used in cave country has a lot less life in them. The practice of overfills should be stamped out, there is no reason for it and it's potentially dangerous.

To give but one example, the power in the common AL80 cylinder if it could be harnessed is enough to lift a firetruck completely off the ground, and if I remember right they claim it can lift it 6 stories.

IMO don't count on overfills, and don't ask for them.

skdvr
04-09-2008, 08:07
GO HP.

For the reasons listed above...

Phil

cmburch
04-09-2008, 11:14
LP vs HP question - ScubaBoard (http://www.scubaboard.com/forums/tanks-valves-bands/226400-lp-vs-hp-question.html)

Here is the SCUBABoard link to LP vs HP

No Misses
04-09-2008, 11:45
Roy, you have stated that your family runs a dive boat. What size tank holders do they have? Most boats around here have tank holders for AL80's. Any 7.25" dia cylinder will fit. When somebody shows up with an 8" dia cylinder they have to use bungie cords, instead of the provided brackets.

Don't get me started on the practice of overfilling cylinders.

My 2c: Get the HP100

cogrwy
04-09-2008, 11:47
I started with an LP95 and kept wondering why I could stay down as long with an AL80 as my steel 95. One day I was checking the XS Scuba website and realized that to get 95 cu ft in the LP95, you have to overfill it to 2640 psi (10% over). My dive shop was only filling it to the rated 2400 psi. That's 10% less air. I was only getting 85 cu ft or so out of my "95 cu ft" tank. Now I have two HP 100s, rated at 3442 psi. Even if slightly underfilled, I still get as much or more air as with the 95. The weight difference is insignificant. Wish I had started with the HPs. Also, I can't confirm this, but I have been told that with an LP tank, you can only overfill until the first re-hydro. Then it becomes an LP85.

MSilvia
04-09-2008, 11:50
If you get 3200 psi in an LP tank, you had better slink away without saying a word, else you risk getting someone in trouble.
A year or two ago, I accidentally got 106 cf put in an old steel 72 by a shop monkey who apparently didn't realize not all my tanks were HP. I dove it, but I also mentioned it the next day, the shop was only too happy to replace my burst disks with some that were a little more reasonable.

RoyN
04-09-2008, 13:03
Roy, you have stated that your family runs a dive boat. What size tank holders do they have? Most boats around here have tank holders for AL80's.

Here is the picture of the boat.

http://www.beachhopper2.com/images/600_Side_Tank_Area.JPG

The boat will hold any size tank and support doubles too. :smiley20:

CompuDude
04-09-2008, 14:15
I started with an LP95 and kept wondering why I could stay down as long with an AL80 as my steel 95. One day I was checking the XS Scuba website and realized that to get 95 cu ft in the LP95, you have to overfill it to 2640 psi (10% over). My dive shop was only filling it to the rated 2400 psi. That's 10% less air. I was only getting 85 cu ft or so out of my "95 cu ft" tank. Now I have two HP 100s, rated at 3442 psi. Even if slightly underfilled, I still get as much or more air as with the 95. The weight difference is insignificant. Wish I had started with the HPs. Also, I can't confirm this, but I have been told that with an LP tank, you can only overfill until the first re-hydro. Then it becomes an LP85.

Potentially, but not necessarily, true.

You need to take your LP tank to a special hydro facility that can re-instate the "plus rating" that allows the 10% overfills. There are a LOT fewer of these facilities than regular ones.

So yes, if you cannot find a hydro facility that can offer to recertify your plus rating on your LP tank, after the first hydro, it's only good for 2400 psi. (LP95 @ 2400 psi = 86 cf)

HP tanks are good to 3442 (or whatever the particular rating is) for life. It either passes, or it doesn't. None of this plus rating nonsense.

RoyN
04-09-2008, 14:28
Well CompuDude, I just paid for a HP100 tank and I'm saving up for another HP100 tank. Now all I need to do is beging thinking of getting a twin steel 80 tank. :D

CompuDude
04-09-2008, 14:43
Well CompuDude, I just paid for a HP100 tank and I'm saving up for another HP100 tank. Now all I need to do is beging thinking of getting a twin steel 80 tank. :D

Doubles HP80s are pretty miserable for most people to trim out. I'd consider doubling the 100s instead... those make some sweet doubles!

RoyN
04-09-2008, 14:46
Two HP100? Oooo, thats gonna make the boat charter wondering where I am as I might take TOOO long underwater! ;)

I know this is a wild dream, but having one double HP100 and a single HP100 a great thing? My mom gives discounts for double tank with manifold. :D

The only thing I need is a second regulator.

CompuDude
04-09-2008, 15:15
Two HP100? Oooo, thats gonna make the boat charter wondering where I am as I might take TOOO long underwater! ;)

I know this is a wild dream, but having one double HP100 and a single HP100 a great thing? My mom gives discounts for double tank with manifold. :D

The only thing I need is a second regulator.

The only way to have too many tanks is when you need a bigger house to hold them all. ;)

I have a pair of doubled HP100s, and 3 single HP100s. I'm currently angsting over whether to double a second pair or keep them for beach dives (and loaners for friends at beach dives).

cummings66
04-09-2008, 16:50
I have double HP100's, double HP120's and looking for another HP100 someday. Got a few AL40's as well, but they're not really back gas cylinders.

in_cavediver
04-09-2008, 20:27
1) All DOT hydro facilities are capable of the '+' rating, at least if they can do the HP tanks. The 3AA designation is very common and the + rating originated from storage bottles so it shouldn't an issue. Now, reminding them to do it is another matter.

2) The plus rating is given at hydro. It is possible for a plus rated tank to lose it one hydro cycle and get it back the next. Its merely a variation of the 'normal' test pressure/procedure.

As for overfilling - in this day and age, Compudude is mostly right. If you have a choice between say an LP104 or HP 130 - Go with the 130 every time. The only time to look at LP tanks is when you have other concerns. The biggest one is that there isn't an HP equivalent. Other items such as PP blending trimix play a role as well. (its easier to do in lower working pressure tanks if you don't have a booster)

On overfilling - I'll simply state the original purpose was to get more gas in a tank than you could buy. The HP tanks we talk about today simply weren't available not that long ago. (in 2002, I bought LP 104's as HP130's were merely a rumor)

Is it safe - well, no sane person is going to call handling any compressed gas cylinder truly safe, its not nearly as risky as some like to make out. Simply put, if it was, a whole lot more tanks would have blown up in Florida by now. This practice has gone on for years. Tanks pass hydro and keep going.I'd contend neglect is far more dangerous that overfilling.

Do I recommend it - well no, not today for most cases. Do I do it - well.....I'll take the 5th amendment here.

I will Xnd the notion that a HP100 is a sweet tank and ought to be the 'universal' tank for diving rather than the AL80.

CompuDude
04-10-2008, 00:36
1) All DOT hydro facilities are capable of the '+' rating, at least if they can do the HP tanks. The 3AA designation is very common and the + rating originated from storage bottles so it shouldn't an issue. Now, reminding them to do it is another matter.

Perhaps getting them to do it is the problem. I have been told by a number of shops that their hydro facility doesn't do plus ratings. :smiley24:

I'm personally relieved that I recently sold the last of my LP tanks.

Grin
04-10-2008, 08:39
Back to the HP100 vs LP95. If you don't mind the size difference you can save some bucks would be the situation. But you could get a HP120 that is around the same size as the LP95 (kind of). With Lp tanks you can use Yoke connections with zero sweat. But when using HP tanks you should use DIN, but don't have to. I would take the HP100 over the LP95 for a couple reasons. 1. I already have DIN everything. 2. Physical Size 3 my shop has no issues filling HP tanks correctly.
Personally I would buy HP120s for about $30 more than the Hp 100s. HP 100s are about 2 inches shorter than a AL80, HP120s are about 2 inches taller than the same AL 80. All the same diameter. LP95s are only available in the larger 8 inch diameter size. That's fine if all your tanks are that diameter, but kind of a pain if you mix your tanks diameter sizes. The LP85 is the smaller 7 inch diamter like a AL 80 or HP100. Here in Florida(I guess we're the only one who gat this) it is easy to get LP tanks filled to around 3000. Many people fill them to well over 3500. My shop had to put a stop to people demanding 4000 in Lp120s and 130s. 3000 or close to that is no big deal(my opinion), but 4000 is kind of nuts. I have some LP85s that I get 3000-3300 fills in routinly. That makes them around 100s.
What I found was: When I got HP100s I found very little difference between those and a AL80 except superior weighting. I sold my HP 100s and bought HP120s. Now I see a huge difference. I can do 20+ extra minutes on a dive, and still come up with well over 500 lbs when I hit the surface(like your suppossed to). Now I'm diving tables instead of my tanks capacity.
SO you can suck a AL 80 dry, or get a extra 5-10 minutes out of a HP100 and still suck it dry, or get HP 120s and get 15-20 minutes more BT and hit the surface with that 500lbs you are supposed to have at that point.
Sucking AL 80s dry is one thing(still shouldn't do it), but you defiantly don't want to suck a steel tank dry. Getting water in steel tanks is a serious screw up. Any time you suck a steel tank dry you need to inspect it. You should do AL tanks also but they are both cheap and AL(less prone to corrosion). People suck AL 80s dry continually. That is something to think about if you presently hit the surface with 0-200lbs routinly while diving AL80s. Many people do this. If your spending a fortune on steel tanks you should get the benefit of the correct amount of gas you need, which steel tanks offer. The HP100 sounded great to me at first, but they really were not what I needed when I added up the real situation. Physical size and about 5 lbs of lead is the only benefit I see in steel 100s, and a tiny bit of extra gas. Is $350 for each Hp 100 worth that extra 15 cf. I say get 35 extra CF(HP120s) for around $380. Damn things are expensive!

skdvr
04-10-2008, 09:38
Back to the HP100 vs LP95. If you don't mind the size difference you can save some bucks would be the situation. But you could get a HP120 that is around the same size as the LP95 (kind of). With Lp tanks you can use Yoke connections with zero sweat. But when using HP tanks you should use DIN, but don't have to. I would take the HP100 over the LP95 for a couple reasons. 1. I already have DIN everything. 2. Physical Size 3 my shop has no issues filling HP tanks correctly.
Personally I would buy HP120s for about $30 more than the Hp 100s. HP 100s are about 2 inches shorter than a AL80, HP120s are about 2 inches taller than the same AL 80. All the same diameter. LP95s are only available in the larger 8 inch diameter size. That's fine if all your tanks are that diameter, but kind of a pain if you mix your tanks diameter sizes. The LP85 is the smaller 7 inch diamter like a AL 80 or HP100. Here in Florida(I guess we're the only one who gat this) it is easy to get LP tanks filled to around 3000. Many people fill them to well over 3500. My shop had to put a stop to people demanding 4000 in Lp120s and 130s. 3000 or close to that is no big deal(my opinion), but 4000 is kind of nuts. I have some LP85s that I get 3000-3300 fills in routinly. That makes them around 100s.
What I found was: When I got HP100s I found very little difference between those and a AL80 except superior weighting. I sold my HP 100s and bought HP120s. Now I see a huge difference. I can do 20+ extra minutes on a dive, and still come up with well over 500 lbs when I hit the surface(like your suppossed to). Now I'm diving tables instead of my tanks capacity.
SO you can suck a AL 80 dry, or get a extra 5-10 minutes out of a HP100 and still suck it dry, or get HP 120s and get 15-20 minutes more BT and hit the surface with that 500lbs you are supposed to have at that point.
Sucking AL 80s dry is one thing(still shouldn't do it), but you defiantly don't want to suck a steel tank dry. Getting water in steel tanks is a serious screw up. Any time you suck a steel tank dry you need to inspect it. You should do AL tanks also but they are both cheap and AL(less prone to corrosion). People suck AL 80s dry continually. That is something to think about if you presently hit the surface with 0-200lbs routinly while diving AL80s. Many people do this. If your spending a fortune on steel tanks you should get the benefit of the correct amount of gas you need, which steel tanks offer. The HP100 sounded great to me at first, but they really were not what I needed when I added up the real situation. Physical size and about 5 lbs of lead is the only benefit I see in steel 100s, and a tiny bit of extra gas. Is $350 for each Hp 100 worth that extra 15 cf. I say get 35 extra CF(HP120s) for around $380. Damn things are expensive!

Well first about the using Yoke on a HP tank. It is perfectly safe to use a yoke on a 3442 psi HP Tank. Espically the newer style yokes. When you get to the older TRUE HP tanks that are rated to 3500 psi then you have to use a DIN. And as far as the HP 120 being better because of more gas than the HP 100, I agree and disagree at the same time. It really depends on the person. I personally have two HP 120's (doubled), 1 HP 130, and 2 AL 80's. I do like the bigger tanks. I can see where using the HP 120's as singles could be problematic for someone a little shorter. I had a buddy use one of the 120's before they were doubled up and he is only about 5'6", he said that he kicked the tank a few times, but he is a bit of an air hog and really liked the extra air. I think that the HP 100's are SWEET tanks. I would love to have one or two of them. There size makes them very easy to handle and a extra 20 cu ft is a nice thing. There are a lot of variables that go into buying a tank. They are expensive (for steel) so you really have to look at what is right for YOU. If you spend the money on them and take care of them they will last you a long time.

Just as another example. I was talking to a buddy this past weekend about buying a set of doubles for himself. He asked me if I liked mine and I said yes. He liked the idea of the bigger tanks for more bottom time, or for more dives out of one fill, but at 100+ lbs they are a little more than his 145 lbs frame could handle. He did not want to have to deal with the length and weight of them, so a better bet for him is HP 100's, which is pretty much what he decided on.

It is good to get on here and ask questions, to get the OPINIONS of others. In the end though each person needs to make the descision for themselves...

Have a good one...

Phil

cmburch
04-10-2008, 10:05
Well first about the using Yoke on a HP tank. It is perfectly safe to use a yoke on a 3442 psi HP Tank. Espically the newer style yokes. When you get to the older TRUE HP tanks that are rated to 3500 psi then you have to use a DIN. ...


I have HP130's with the new Pro Valve. When I asked about the Yoke vs DIN on the HP tank, the LDS did not say it was OK to use yoke at 3442PSI. But why would XS SCUBA sell their HP tanks configured this way. Can Yoke really be used for 3442PSI?

skdvr
04-10-2008, 10:29
Sure it is just fine to use the Yoke on a 3442 tank. That was one of the reasons for HP tanks going below the 3500 psi mark (I think). DIN is a more secure way of attaching your 1st stage to the tank, but there is absolutly nothing wrong with using your Yoke on the 3442 tanks. I have been using mine that way on my HP 130 for over a year now with no problems what so ever.

Years ago (not sure how long) yokes were made thinner than they are today and I have heard that they could actually stretch over time of being exposed to higher pressures. The Yokes of today are much more robust and can handle the higher pressures much more easily.

So use your Yoke without fear.

Phil

cmburch
04-10-2008, 10:33
Thanks,
I have a DIN, but most of my buddies have yokes. So they do not have to change to use my tanks.

skdvr
04-10-2008, 10:43
Thanks,
I have a DIN, but most of my buddies have yokes. So they do not have to change to use my tanks.

Correct, just slap in your little insert and they can use your tanks without worry...

Phil

RoyN
04-10-2008, 12:03
Guys...if I want to have 3400psi and up I should convert my regulator to din?

skdvr
04-10-2008, 12:07
Only if you are going to 3500 psi tanks. Otherwise if you want to convert to DIN go for it, but you do not have to...

Phil

Sounder
04-10-2008, 12:16
Yeah, you don't NEED to convert but a DIN fitting is a more secure way to attach your first stage. I've seen o-rings blow on yoke tanks, even on Al80s that were well below 3000psi when the o-ring failed. I've never seen a DIN fail... yet. I'm sure that day will come too, but it is fairly widely accepted in my area that DIN is a stronger connection.

My opinion is that DIN is a stronger connection and that I can always put an adapter on it when I go to the tropics to use yoke-style valves.

cummings66
04-10-2008, 12:17
My tech instructor wants all his students to have DIN connections, other than that requirement I'd say do what you feel comfortable with. I use DIN for my gear, and have from the start.

I saw a DIN failure, of course the O ring he used was from a hardware store and probably not the right one to use. Probably a low shore value.

RoyN
04-10-2008, 12:22
I've been wanting to go din for a while. :p I was just waiting to decide whether to go double tank or get a steel tank. And now I did, I gotta save money for the din conversion.

CompuDude
04-10-2008, 13:54
The HP100 sounded great to me at first, but they really were not what I needed when I added up the real situation. Physical size and about 5 lbs of lead is the only benefit I see in steel 100s, and a tiny bit of extra gas. Is $350 for each Hp 100 worth that extra 15 cf. I say get 35 extra CF(HP120s) for around $380. Damn things are expensive!

An Al. 80 holds 77.4 cf of gas. And HP100 holds 100cf of gas (assuming a proper fill.) That's nearly a third more air than an Al.80... how is that just "a little more gas"?

Naturally, an HP120 is a lot bigger... 20% more than the HP100. But it's a LOT bigger and a LOT heavier for that extra gas. Unless you need the gas, I'm not a fan of them. (Of course, that's partially because I do a lot of shore dives, and weight matters a lot more for shore dives than boat dives. On boat dives, screw it, bring the biggest tanks you own since you only have to carry it 10 feet to the gate!)

Sounder
04-10-2008, 14:52
My vote will ALWAYS be for a HP100 over an Al80... worth every penny. Al80's make great monkey diving and stage bottles!!

cmburch
04-10-2008, 16:08
I've been wanting to go din for a while. :p I was just waiting to decide whether to go double tank or get a steel tank. And now I did, I gotta save money for the din conversion.

http://www.leisurepro.com/Prod/SCPDC3.html?Search=op%3ddtSearch%26Term%3ddin%2bco nversion%26SearchFlag%3dall%26AdvSrchSortField%3dR elevance%26DescSort%3d0%26Description%3don%26Hit%3 d1

I converted mine yoke to DIN for a US Divers SEA for about $35.

RoyN
04-10-2008, 16:28
http://www.leisurepro.com/Prod/SCPDC3.html?Search=op%3ddtSearch%26Term%3ddin%2bco nversion%26SearchFlag%3dall%26AdvSrchSortField%3dR elevance%26DescSort%3d0%26Description%3don%26Hit%3 d1

I converted mine yoke to DIN for a US Divers SEA for about $35.

Thanks Charles, but I have to do the conversion from my parent's shop. :smiley5: But the good thing is I get a discount on no labor charge too as its my dad doing the conversion! :smiley20: The only thing is I have to do something in return for him. :smiley36:

Anyways, gonna get my HP100 tanks and I'll get a second one in the very near future.

skdvr
04-10-2008, 17:09
You have to be carefull when trying to pair up steel tanks that you did not buy at the same time. They are not as uniformally made as AL tanks, and could be slightly different sizes and weights. I am not sure how much this will throw you off if you double them up. Just something that I have been told, and thought I would pass it along...

Phil

CompuDude
04-10-2008, 17:33
You have to be carefull when trying to pair up steel tanks that you did not buy at the same time. They are not as uniformally made as AL tanks, and could be slightly different sizes and weights. I am not sure how much this will throw you off if you double them up. Just something that I have been told, and thought I would pass it along...

You've been told right. It took me 6 months of dragging my Worthington HP100 into every shop in SoCal, trying to find a match, before I finally found one. :smiley11:

Fortunately I wasn't in a hurry at the time. And of course, right after I finally found and bought a match, a great deal fell into my lap, and I ended up buying a new matched pair of Fabers before I had a chance to double the original ones, so they get dived as singles now. LOL

Sounder
04-10-2008, 17:45
You have to be carefull when trying to pair up steel tanks that you did not buy at the same time. They are not as uniformally made as AL tanks, and could be slightly different sizes and weights. I am not sure how much this will throw you off if you double them up. Just something that I have been told, and thought I would pass it along...

You've been told right. It took me 6 months of dragging my Worthington HP100 into every shop in SoCal, trying to find a match, before I finally found one. :smiley11:

Fortunately I wasn't in a hurry at the time. And of course, right after I finally found and bought a match, a great deal fell into my lap, and I ended up buying a new matched pair of Fabers before I had a chance to double the original ones, so they get dived as singles now. LOL

I just traded a 2006 Worthington HP100 for a 2003 PST HP100 because it matched my other one... and I'm twinning them up (after hydros! uugh.)

cummings66
04-10-2008, 18:28
It's not that bad, the hydro's that is.

For what it's worth, during my EOI course we were told it's common for cylinders to vary, the new part was that even the AL ones that are the same brand will vary.

My older PST HP100's seem to be all pretty much the same, I'm not sure why but the older PST's, IE the very first ones that are painted and not galvanized seem to be fairly uniform.

Grin
04-11-2008, 08:15
The HP100 sounded great to me at first, but they really were not what I needed when I added up the real situation. Physical size and about 5 lbs of lead is the only benefit I see in steel 100s, and a tiny bit of extra gas. Is $350 for each Hp 100 worth that extra 15 cf. I say get 35 extra CF(HP120s) for around $380. Damn things are expensive!

An Al. 80 holds 77.4 cf of gas. And HP100 holds 100cf of gas (assuming a proper fill.) That's nearly a third more air than an Al.80... how is that just "a little more gas"?

Naturally, an HP120 is a lot bigger... 20% more than the HP100. But it's a LOT bigger and a LOT heavier for that extra gas. Unless you need the gas, I'm not a fan of them. (Of course, that's partially because I do a lot of shore dives, and weight matters a lot more for shore dives than boat dives. On boat dives, screw it, bring the biggest tanks you own since you only have to carry it 10 feet to the gate!)

I thought I already covered this but here it goes again:
Most people (but not everyone) find AL80s don't give them the bottom time they want, so they push it right to the max before accending(example: meaning surfacing at 400-500PSI instead of 1000PSI from around 80ft depths). This routine practice ends up with a situation where you become accustomed to hitting the surface with, lets say, 100PSI (or less, or zero). I doubt anyone here would be suprised to realize that doing this routinly will end up with, the occassional accent, ending up with a completely empty tank at your safety stop. This means a not so great last 10-20 ft accent on one or two breaths. I've done it, but I am actually not nearly as guilty of this as many others are. I see this practice all the time.
So now you buy a HP 100, and get a extra what? No extra bottom time if you stop your sucking tanks dry practice, or a extra 5-10 minutes if you continue your surfacing with zero PSI practice.
As I thought I stated in the previous post: get the 120s and you get extra bottom time(alot) and you wil surface with 500-maybe even 1000 PSI in your tank. When you dive every week a couple times it is nice to have this cushion.
A recent situation I found myself in made the "plenty excess of PSI cushion" very nice. Upon accent I got a vertigo hit and I calmly stuck at 40 ft deep for about 3 minutes, waiting it out and gathering my thoughts, then accended extremly slow from there(added about 5 minutes to my accent). With a AL 80 and limited gas, I would have not had that luxury.
I know the proper way to dive(by the book) is to start your accent at a pressure level that gets you to the surface with plenty of excess PSI. I'm just stating, reality is few AL 80 divers do that. So, when buying new Steel tanks, and paying serious cash, it is a good idea to put that factor into your purchase.
As someone else stated, there is alot that goes into purchasing correct tanks for everyones specific needs. I am just stating why I choose what I chose and hoping they read something into it, to help make their decision. I hate to repeat, but there you have it AGAIN!
Simply put: If you are honest with yourself and you say to yourself "Damn I am one of those guys who surfaces with zero PSI everyonce in awhile, because I try to max my bottom time, and sometimes cut it too close". You might want to reconsider the idea of thinking a HP 100 will get you much of anything. Or maybe not!
I can count the time that a diver has got back onto my boat with more than 300PSI, in a AL 80, in the last three years on one hand. With 120s I can count the number of times someone has gotten onto my boat after a dive with less than 500PSI on one hand. If you only dive once every month or so the odds are in your favor, but we dive virtually every week at least once. As I already stated, again, I tryed HP100s and sold them for this very reason and bought 120s. Thus this post trying to save soemone else the same headache! It's a easy mistake to make. O fcourse HP100s are great tanks and many might find them perfect for their dive profiles. I'm just trying to give some thought to the decision. Everyone dives different profiles routinly, and that's where the decsion needs to come from.

http://www.xsscuba.com/tank_steel_specs.html

120 is 4 inches taller than a 100. Virtually same bouyancy. And 5 lbs heavier out of the water. $30 more

in_cavediver
04-11-2008, 11:08
Grin,

Nothing personal but the practices you describe are nothing short of reckless. While I agree with you that the tank should match your objective, I find it somewhat irresponsible to recommend a 'big' tank to someone who can't manage their air to start with.

Now, we have people who have enough gas to really get themselves into trouble. Simply put, if they can't limit dive time to gas now (with an 80), how do you know they cannot limit thier bottom time with more gas later AND have the NDL issue as well. I see these divers coming up with zero gas AND getting bent because of it.

cmburch
04-11-2008, 12:01
I thought I already covered this but here it goes again:
Most people (but not everyone) find AL80s don't give them the bottom time they want, so they push it right to the max before accending(example: meaning surfacing at 400-500PSI instead of 1000PSI from around 80ft depths). This routine practice ends up with a situation where you become accustomed to hitting the surface with, lets say, 100PSI (or less, or zero). I doubt anyone here would be suprised to realize that doing this routinly will end up with, the occassional accent, ending up with a completely empty tank at your safety stop. This means a not so great last 10-20 ft accent on one or two breaths. I've done it, but I am actually not nearly as guilty of this as many others are. I see this practice all the time. ...


All I can say is "Holy Scheiße!!!" Hanging around 80' with less than 500psi then the described ascent technique. Who in their right mind? Not anyone I dive with.

My English version got edited to "Holy ****!!!"

Sorry Grin, I do not mean to be rude or controversial. Maybe the Pacific Ocean is different. I looked at your unfilled profile, but noticed you buddied up with No Misses. If your post was a mistake and is edited, I will delete this post.

RoyN
04-11-2008, 12:23
The real reason why I went from AL80N to Steel is I'm moving to drysuit and having a steel tank, I believe is better then the AL80N because some weights are now shifted into the tank instead of carrying 2 or 3 pounds. Other then that, I think the rule is divers should have 500 psi when they are back at the surface or boat? Can anybody verify that?

cmburch
04-11-2008, 12:47
We normally agree upon a specific PSI to begin our ascent before we submerge or even put a foot in the water. We will also remind each other about it on top of the water before we submerge. We also check each other out again before submerging. It is not the PSI we want at the surface. We normally have a start kicking back towards shore or boat at a specific PSI which may be 1200 psi - as well as a begin to ascend PSI agreed upon maybe 500-700 PSI at shallower depths.

500 surface maybe good. I have been less than 300PSI with Al80's before. What if someone needs help that is still submerged and you have to return? We have surfaced before with some of the group still hanging on at 15 ft.

RoyN
04-11-2008, 14:46
I leave the bottom when I have 1200psi because I sometimes do a 50ft 1 minute stop if I hit around 80-110ft and then go up and do a full safety stop at 15ft for 3 minutes. When I get on the boat, I should have only 500-600psi. The only time my tank was sucked dry was because some diver was out of air and she pretty much sucked my tank dry. I had about 1900psi at the time when I started giving her my regulator.

Sounder
04-11-2008, 15:20
This is a link to gas planning that I think everyone should know. A good friend put this into an easy to read and understand format along with tables for quick reference. Please folks, read this and consider adding it to your dive planning. There simply is no excuse for running out of air.

Rock Bottom:
Rock Bottom and Gas Management for Recreational Divers (http://www.scriptkiddie.org/diving/rockbottom.html)

I think it is a crime, and completely irresponsible, that NONE of the largest agencies teach this.

cmburch
04-11-2008, 15:34
I like to do 80-85' dives, but rarely do. Maybe a few times a year and have only gone around 100 ft once or twice in my life. Most of my dives are at 45-65'. I consider myself lucky if I get down to 65' kicking from the shore. That is why we are normally in 30-40' water on the way back to shore when we surface at the agreed upon say 700PSI.

skdvr
04-11-2008, 16:53
This is a link to gas planning that I think everyone should know. A good friend put this into an easy to read and understand format along with tables for quick reference. Please folks, read this and consider adding it to your dive planning. There simply is no excuse for running out of air.

Rock Bottom:
Rock Bottom and Gas Management for Recreational Divers (http://www.scriptkiddie.org/diving/rockbottom.html)

I think it is a crime, and completely irresponsible, that NONE of the largest agencies teach this.

Hey Sounder, thanks for the link. It is an interesting and informative read...

Thanks
Phil

CompuDude
04-11-2008, 16:55
Grin,

Nothing personal but the practices you describe are nothing short of reckless. While I agree with you that the tank should match your objective, I find it somewhat irresponsible to recommend a 'big' tank to someone who can't manage their air to start with.

Now, we have people who have enough gas to really get themselves into trouble. Simply put, if they can't limit dive time to gas now (with an 80), how do you know they cannot limit thier bottom time with more gas later AND have the NDL issue as well. I see these divers coming up with zero gas AND getting bent because of it.

Holy crap, no kidding. I concur completely.

Grin, what you are describing is fixing a very serious skills problem with gear. You're taking a diver who does not have the skills to manage their own air supply and handing them a tank that will just end up getting them in worse trouble, as in_cavediver pointed out.

Additionally, the OP never said that he was overly limited by Al.80s and needs a bigger tank to avoid coming up empty... so it seems like you're giving unnecessary advice, that's dangerous, to boot. I could be wrong, but Roy does not strike me as the kind of diver who frequently accidentally finds himself OOA (or close to it) because he wasn't paying attention.

cummings66
04-11-2008, 16:56
Simply put: If you are honest with yourself and you say to yourself "Damn I am one of those guys who surfaces with zero PSI everyonce in awhile, because I try to max my bottom time, and sometimes cut it too close". You might want to reconsider the idea of thinking a HP 100 will get you much of anything. Or maybe not!

Quoting from my TDI Decompression Procedures book.

Many say that the buddy is there in case you run out of air. It may sound harsh and cruel, but just what the hell are you or your buddy doing running out of air/gas?? Running out of a breathing gas is simply not to be tolerated. If a buddy has the habit of running out of air, then get another one, that person is way to dangerous to be diving with!

cogrwy
04-12-2008, 20:23
With regard to dive planning, the "Rule of Thirds" is useful. Whatever your starting PSI at the surface, use one-third for your descent and exploration and turn the dive with two-thirds left. Get back to the ascent point with one-third left. Adjust as necessary based on your consumption rate. Bottom line is: leave yourself that 500PSI cushion at the surface.

Grin
04-13-2008, 09:15
I had to delete this post. Too bad becasue it was a good one. But it dosn't belong on this site.

If you guys read that, you will see I am talking about most of you, not me! Just stating what I see YOU guys doing. I did it a few times / for awhile and fixed my profile issues. Everyone needs to figure out thier own profile for themselves. Of course there are some who are compleley freaked out on the thought, and they, somehow, are here telling me I'm nuts:smilie39:. Any trip on any cattle boat always has me leaving wondering how people survive. Not me, You! Believe me, I am completely safe and probably would kick most of you off my boat after one dive. It's been done quite a bit. Finding good divers to dive with, is what diving is all about for me.

I'm not sure what the, I dive with "No Misses", comment meant there, but we were diving all day out of my boat yesterday. 4 solo dives each to around 70-80 ft, and noone on this boat was sucking tanks dry or breaking any tables, not even close (like I said "reread" I'm talking about YOU, not me). I have personally not seen a single caution bar on my computer in a couple years. That includes N02/O2/or accent. I'm willing to bet my dive profiles and settup, are much safer than virtually everyone here. I gaurantee my accents are safer than, probably, everyone on the planet. I am on the overkill accent safey plan. But I don't preach my way is the only way
.
I'm sure there are those who are super cautious and that's great! But I find it a bit silly for them to think everyone in the world does everything their way.

Is this scuba class or scuba discussion. Do you want to hear anyone elses experience, or generate thought, or hear how soem people do things or do you just want PADI text cut and paste?

If you really want to freak out. There are many guys that do 180 ft spearfishing dives on a AL80 with air daily. They didn't dream this up yesterday, and have been doing it for many many years. I find it interesting, but no way in hell would I do that! Do I tell them they are nuts and freak out! No! Can I state that other people do this and not get accussed of being a idiot for what I practice on here? Obviously not!
Not me! YOU! Some of you do stuff and won't even admit it to yourself.
Of course there are the people who do stick directly to the rules 100% with zero thought as to why. That's fine with me also!
My post was to make people think, who might find themselves doing as many do. My post came form my experience and how I fixed my issues. I explained it all twice. Can you guys read? Or are you just he type that reads the first word and screams bloody murder? As much as some of you post I think that's a high probability. I would be highly entertained to see people limited to 5 post a day. Some of you would commit suicide.:smilie39:

Splitlip
04-13-2008, 09:32
Reality is, if you get on any cattle dive boat, 1/2 the people on each dive come up with around 100PSI as they climb on the boat. I have not been on a cattle boat for a couple years, but every time I have been on one, I wonder how it is that there are not more dive fatalities.
500 PSI is plenty to get you a extremely safe, 8 minute, accent from 80 ft. I have done it 500+ times on AL 80s and HP 100s. The only thing is, you will be at 100 or (most likely) less when you get to the top, thus you really should be starting your accent at 800+PSI to be safe, or 1000 by the book.

I am with Grin on this one. He stated facts.

One of the things with drift diving on cattle boats, many divers don't want to surface without the protection of the float. See threads on getting hit by boats. Or they don't want to surface too far from the surface support after their safety stop.
Yes, they should learn to shoot a bag, but not everyone can. And the "make a circle with your fingers" around the float line burns more gas as the diver struggles against the current IF he can manage to keep up with it.

cummings66
04-13-2008, 10:03
Books were written to help divers get better and safer, it's why there are courses to instruct you on how to dive safely. When it comes to safety you can never preach too much. We must always consider safety when diving and to quote a text book which says the obvious is not out of line. It is a truth, one that should be spoken loudly of, not hidden in the back rooms like it was a dirty lie.

IMO, it is quite right to say running out of air at depth is bad, and if that happens to a person all the time then they should examine why it happens to them. To truly make that diver safe means that they need to start taking responsibility for the dive plan and actively following it. There is no excuse for running out of air, unless you had a gear failure with no remedy available.

That said, I have HP120's and HP100's. I use the 100's most of the time because their characteristics are ideal. They're also lighter and my back likes that fact.

Technical courses are interesting to me in that they require a degree of precision which recreational diving does not. I think many of the goals interrelate and should be used by the other. It's one reason I like that side of the house, I like to be in control. I'm not the person who's content to be along for the ride, I want to plan things out in detail and I delight in seeing that plan work.

It works in recreational diving. Yesterday I went diving and took somebody who I've never dove with, but we did a real basic plan where we'd just go down to 55 feet or so and look at all the stuff there, and end up with 500 psi on the surface. So I introduced him to the basics of gas planning. I explained the for this dive I didn't really care about rock bottom and that all we needed to do was figure out how much air he'd use coming back up and doing a 3 minute safety stop. If I recall the number right we decided we'd need 6.5 cf of air to do it. We translated that to psi which was 700 psi for the turn pressure and went diving. At 700 psi we ascended to the SS for 3 minutes while I practiced valve drills and at the end we surfaced. He had 500 psi left. I had 2000 psi. The dive went like clockwork and was a perfect example of what can be done and how it's not hard and it does make the dive safer.

Grin
04-13-2008, 10:04
Thank you! that's all I'm trying to state is a little reality. Not textbook how it's suppossed to be. I'm glad noone quoted much of my original thread yet before I deleted it. There are many reasons for many different types to find themselves in the non textbook situation. When that happens they need to adjust. Thinking is involved! Hopefully a few others read my post and thought a little, instead of kneejerking.

cummings66
04-13-2008, 11:09
The reality is different cylinders exist because of different needs. Not everybody wants an AL80, nor the LP95 or Hp100. Not everybody can carry those cylinders either.

I'm a fan of the OLD HP100's because they're lighter than the new ones. If I was buying a new one I might consider the HP120, which is why I got it in the first place. For some reason I don't get, the new cylinders seem to weigh more. Maybe they'll last longer? Not sure, my HP100's are from 1987 or so, the very first year they came out. That's a pretty long lifespan, I might not be around to enjoy it if the newer ones last longer.

in_cavediver
04-13-2008, 17:05
Thank you! that's all I'm trying to state is a little reality. Not textbook how it's suppossed to be. I'm glad noone quoted much of my original thread yet before I deleted it. There are many reasons for many different types to find themselves in the non textbook situation. When that happens they need to adjust. Thinking is involved! Hopefully a few others read my post and thought a little, instead of kneejerking.

Grin,

As I said, its nothing personal at all. I venture to bet 99% of the divers on this board (including you) are safer than your average diver or even your average 'good' diver. Of course, that's a selective pressure for people looking to better themselves that come here.

I can say, I have some issues that I need to watch. Complacency is my enemy. I have fallen victim to it in the past and I need to keep vigilant so I don't let it happen again. (no problems just not as much attention to detail as it should). I may exceed NDL's but I haven't deviated from a set dive plan in any dangerous way ever, even in two aborted dives due to minor gear failures.

I do think we all agree that for diver safety, said diver has to be able to think. To do that, they have to understand the reasons of diving. To do both of those, they have to take responsibility for themselves, which in many cases, doesn't happen.

I still don't like the idea of trying to use gear to solve a personal responsibility issue - IE running out of air. Sometime gear upgrades/additions can be an asset - such as a nitrox analyzer so you always can check your gas, even if you forgot at the shop. That said, I don't like the jump to say 'he came back with 100psi, he needs a bigger tank' still doesn't sit right with me. I say he came back with 100psi - what went wrong? If the answer is nothing, then I say - you need to manage your air better. People have died due to this.

Again, its only my opinion

RoyN
04-14-2008, 00:16
I really small Matt, the HP100 tank is about the same size as my AL80N, but a little smaller. Just perfect for me :D

cmburch
04-14-2008, 02:27
Yes,
The HP100 is also my favorite size due to weight 5lbs less than HP120 and shorter. No need to get my head hit or butt bumped. Also my buddies have smaller tanks so it would be a waste for me when surfacing at the same time.

RoyN
04-15-2008, 15:43
Found this online. Think this is a good buy as well?

SCUBA DOUBLE 95s BANDS AND MANIFOLD (http://sfbay.craigslist.org/eby/spo/642642237.html)

cummings66
04-15-2008, 18:18
A lot of things go into the is it a good buy question. Who made the cylinders? What is the original hydro date? Did it get regular overfills? How high if it did? Is there any corrosion on it?

Who made the bands, the manifold?

Those things will vary the price. Is it worth the price he's asking, probably. New would be much more than that.

RoyN
04-17-2008, 13:23
The tanks are worthington lp95 so that we know, the manifold is dive rite and are dins. The problem is, the tank is in pending so too late for me. But with the upcoming gears coming in, I probably won't be able to afford too much. :(

cummings66
04-17-2008, 16:34
If I was local I'd buy that then, very good deal IMO. I like the cylinders, the manifold is good, and I'll bet the bands are Highland based on the choices he's made so far.

Even so, the band is the lesser of the parts.

RoyN
04-26-2008, 22:33
My HP100 tanks have been O2 clean, and all they need is to get the nitrox sticker and is ready to go! :D

HuntsDesk
02-06-2009, 00:03
Is it safe - well, no sane person is going to call handling any compressed gas cylinder truly safe, its not nearly as risky as some like to make out. Simply put, if it was, a whole lot more tanks would have blown up in Florida by now. This practice has gone on for years. Tanks pass hydro and keep going.I'd contend neglect is far more dangerous that overfilling.

Do I recommend it - well no, not today for most cases. Do I do it - well.....I'll take the 5th amendment here.


Agreed. I know plenty of tech/cave instructors in that region who're in the water all week long with overfills . . . and have had no problem. The last instructor i talked to at length about it said he's been filling the same tanks for over 10 years with over fills . . . again with no problems.

Heavy D
02-06-2009, 07:34
Neglect is way more of a concern than overfilling but let me kind of qualify that. A slight overfill (100-150psi) regularly will have little or no effect over the life of the cylinder, after all they are designed to contain about 150% of their working pressure. The problem comes when they are overfilled excessively on a regular basis. Even the metal has some elasticity to it and over time it can lose that elasticity with repeated excessive fills (kind of like a balloon after it is inflated). The loss of elasticity is what causes a tank to fail hydro.

in_cavediver
02-07-2009, 06:07
Neglect is way more of a concern than overfilling but let me kind of qualify that. A slight overfill (100-150psi) regularly will have little or no effect over the life of the cylinder, after all they are designed to contain about 150% of their working pressure. The problem comes when they are overfilled excessively on a regular basis. Even the metal has some elasticity to it and over time it can lose that elasticity with repeated excessive fills (kind of like a balloon after it is inflated). The loss of elasticity is what causes a tank to fail hydro.

I personally would never overfill (500+psi over) and AL tank. I would never overfill a steel exemtpion tank. Only 3AA steels in good condition. Those specific tanks (LP steels) have a good history of tolerating overfills. It does cut the tank life but the tradeoff of gas is worth it for some of my dives. (I bought most of my LP steels before HP equivalents were available)