17 replies to this topic

[Trimix2dive]

OK guys and gal. Lets have a civil discussion for those that don't dive either on the pros and cons of LP vs. HP steel tanks.

And remember your opinion is not wrong, it just differs from the other people who are right. Just kidding - fun fun smile smile.

I personally dive manifolded with isolation 108 (or 112 depending on which rating you follow) LP. Previous to picking this I dove everything from independent doubles, to twin 131's, HP, LP, with and without isolation.

For me the LP 108s had the best full to empty bouyancy characteristics and we relatively easy to handle. I confess I did have at one time a set of aluminum 80s, thought it would be fun since I had some extra tanks. Learned my lesson, so no need to scold me. Thanks.

Let the debate begin - OK folks the floor is now open for debate. Be friendly and provide information that people can learn from.

[Diverbrian]

Presently, I am using HP tanks. The LP tanks are just too heavy for my smaller frame in relation to the amount of gas that they carry at rated pressure (let's not get into "cave fills" here, please. My tech buddies still tease me about my reluctance to do that. My tanks.... my perogative on how much pressure I allow them to see. ).

I have two sets of doubles, HP 130's and HP 100's. The one exception is my oxygen bottle. It is a LP45 for the reason that the dive shop can actually give me somewhat close to it's rated capacity. Pumping oxygen up to 3000 psi is generally not considered a safe idea.

The cons of the HP tanks... you do need to find air stations that can pressurize a tank that high. Most of the time this is not a problem, but sometimes it can be. "Cave fills" (violating my own rule, LOL) are not near as effective at increasing the amount of breathing gas that you are carrying. An HP tank WILL be DIN which can sometimes present a problem with regulator compatibility (see another thread here about that).

Pros.... I can "legally" put a lot of breathing gas in these things and not be as afraid of a problem with hydros, etc. They tend to be more narrow (see my first paragraph) and easier to handle than the small "propane tanks" that the Low Pressure tanks appear to be.

Edited by Diverbrian, 20 May 2005 - 04:29 PM.

[Trimix2dive]

Thats 1 for LP, and 1 for HP. NEXT ?

[Marvel]

I have a matched set of steel 80's (cute little things). Technically, they are LP because they're rated to 3450 psi but my LDS does fill them up to 3600-3700.

[Lubold8431]

I wouldnt consider 3450 LP. Anything under 3000, maybe. 3450, no. Thats HP in my book.

As for the LP vs. HP debate, its a personal choice, and it depends how much of a cylinder you want/need for the type of diving you are doing, and your size. I own both HP and LP cylinders.

[Geek]

I have a matched set of steel 80's (cute little things). Technically, they are LP because they're rated to 3450 psi but my LDS does fill them up to 3600-3700.

Those sound like PST HP tanks. I have a similar set.

The HP tanks can be filled to less than rated pressure, so the only advantages I can see to LP tanks would be cost and availability.

There are folks who like the trim characteristics of specific tanks, but I believe that has more to do with the size, shape and weight of the tanks than whether they are rated HP or LP.

On the other hand if I owned LP tanks and was diving comfortably with them, I wouldn't exchange them. Dive what feels good.

[fbp]

Well I don't know squat from shineola, but started, as most divers did in those days with LP Alum 80's

Got 2, but needed more air. Kept having to come up before my buddies, Ladies? can you Breath just once in a while??

Then in Phase 3 of my diving experience, I got 3 (now 4) Faber HP 120's... loved them, Long Heavy Scud Missile like, but the air capacity was great. I could stay down with the buddies and still have a little air left - I don't see a problem with "Too Much Air". But they were a little long and a little on the heavy side.

So, being the creative shopper that I am, I thought smaller (but wider), length-wise, would be sooooo much better, so popped for 4 of the PST HP 119s.. Lighter, smaller and had the same capacity or close to it.

Had to add weight, heheh, since they were lighter and still, DOH!!! carrying about the same weight, just in different areas.

BUT!!!... I like them a lot.. They:
- Allowed a little shorter length, Tail and head bumping gone
- Allowed the capacity to stay with "Normal Divers" and even those "Breathless Diving Ladies" and still have some air left.
- Allowed for a 3000psi fill and I still could hang in there on a dive. (see Alum 80s)

Fills - typically I look for a minimum of 3000psi. As the LDS is getting more and more better, I'm ending up with a predive fill of apx 3300.. If I get a 3450psi fill, I want to save and treasure it..

But!!... most of the local dives are not something that need using 3450psi and typically I come up with apx 700 to 1200psi left as my buddy runs out, or we get bored due to conditions, so the dive's over. In bad conditions it's just an air top of.

So for me, the HP 119 are great.
- If under filled - 3000psi I can still do the dive with comfort.
- I always, well usually unless I'm up in our Beautiful Neighbors north of us, BC have a good supply of air just in case (Also carry a 30cf pony)
- minor buoyancy at the end
and finally, no "Paint Chips" heheh... they may not look pretty, but they're build to work...

Anyway I like'em. I'm not a techie by any stretch of the imagination, so quoting PSI capacities, length of times doesn't do anything for me...
It's just what works for me...
and I like it...

Until, of course they come out with something Mo'better...
Air Rocks...!!!!

Hope that helps eh????

Edited by fbp, 22 May 2005 - 09:12 AM.

[ScubaDadMiami]

I dive double PST E-7 120s (they fill to 3442 psi). They did require some minor equipment weight reconfiguration at first (especially when diving dry). Now that I have them balanced, they are a pretty sweet ride.

I like them because they are lighter for climbing out of the water compared to low pressure tanks with the same rated capacity. I also think that I can feel a difference when swimming these 7.25 inch tanks through the water compared to 8 inch tanks. They actually fee like they are more streamlined and easier to swim.

Edited by ScubaDadMiami, 22 May 2005 - 01:06 PM.

[scubafanatic]

.........well, for comparison, here's my tank 'inventory':

Faber LP 120 ( 2 ) -which I'm selling, just too long/cumbersome
Faber LP 85 ( 1 ) -sweet little tank, especially for rough shore/boat entries/exits
Faber LP 108 ( 1 ) - lots of capacity, easy to get good fills, even on a boat
Faber LP 85 'doubles' ( 1 ) -decent capacity, not too cumbersome/heavy
Faber LP 76 'doubles' ( 1 ) -decent capacity, not too cumbersome/heavy
PST HP E8 130 ( 1 ) - lots of capacity, strong galvanized finish
PST HP E7 120 ( 1 ) - lots of capacity, strong galvanized finish, streamlined

plus another ( 2 ) PST HP E7 120 that shipped out 5/19 and should arrive next week.

..........I enjoy all the tanks ( except for the 2 LP 120's which I have on sale at my LDS, just too long and cumbersome for me ) .

...lately I've gravitated towards the PST HP tanks.......the 'finish' is more abuse tolerant, especially in salt-water.........and I've gravitated towards the E7-120 model in particular, it's 7.25" diameter is more streamlined in the water.....and the extra length makes reaching the valves UW easier.......moreover, it's the largest capacity tank on the market that is guaranteed to fit any boat tank rack, as many boats can only handle tanks with the same 7.25" diameter as an AL80.

.......I'm considering buying an E7-100 twinset later this year.......tough galvanized finish, decent gas capacity, yet reasonably easy to carry/handle on land.....I'd considered another LP 85 twinset...which are an awesomely well-balanced, realistically weighted tank set.......but ultimately I think I prefer the galvanized PST finish.

Karl

[Cold_H2O]

I have 2 HP 80's and I picked them for a few reasons.
1 - I am kind of short and they are short enough for me to carry comfortably and dont hang down past my knees when on my back.
2 - I love the amount of air they can hold. I always surface with lots of extra air. And never worry that I will have to be the first one to head up.


I also love the din valves that go with HP. I don't know what size my next tanks will be but I do know they will be HP Steel..

[Desert_Diver]

HP steel for me, preferably PST. Anything else is heavier for similar capacity, and it makes a difference at the end of a dive. If you're *just* looking at the weight of the tank empty/full, don't forget to add in the extra lead required to keep you neutral when you're down to 500PSI... or you're not comparing apples to apples. HP steel is more negative than aluminum, so you can shed a little lead with 'em. That's a big plus when you're built like a scarecrow ;-)

Anyone have any info on the new Worthington steels? I've seen 'em mentioned at a couple of websites, but haven't found real data on 'em yet. The teasers looked like the PST E series specs.

I only have 2 of the PSTs 'cos most of my trips from Phoenix are gonna involve a plane, and there's just NO way I want the hassle of hauling 40+ pounds of steel along with my regular luggage. I got 'em for local trips to California if I couldn't rent steels, as most of the boats I'd reviewed in CA only rented Al80 or 95.

[scubafanatic]

Hi Desert_Diver,

...here's a good link to all the features / specs for the new line of Worthington scuba tanks:

http://www.seapearls...anks-steel.html

...their HP line is extremely similiar to the PST HP line....and their LP line is extremely similiar to the OMS/Faber LP tanks...at least in terms of capacity / exterior dimensions / bouyancy.

.....I guess my main 'issue' with the new Worthington line is the painted exterior.....I see that as being higher-maintainance/ lower durability than the PST galvanized exterior.

.....a few of my local dive shops have either dropped PST or carry PST but have added Worthingtons to their 'lines'....... for quite a while now PST has been on major backorder, and some of the shops got fed up with it are promoting the Worthingtons instead.

......the good news on PST is that backorder times have shrunk substantially......and, for example, SucbaToys here in Dallas lists PST tanks on their WWW site....apparently in stock.

....... I just received a pair of PST HP E7-120's this week.......they arrived after a 3 month delay.......which is actually a substantial improvement over the 6--9 month waits divers experienced last year.......so things are getting better availability-wise.

...the PST E7-120's are SWEET tanks.......now have (3) of those....as well as (1) PST HP E8-130 ....so I've been very satisfied with my PST tanks.

Karl

[Desert_Diver]

Howdy, ScubaFanatic!

I'd heard the same stories, that PSTs were impossible to get. The Worthingtons *might* be OK, dunno how permanent their "shotblasting, protective zinc coating, followed by a durable powder coat finish" coatings are. I'd guess the "zinc coating" is a hot-dip galvanize like PST. I've yet to see a painted tank that didn't look terrible after a few years of use. I hunted around a bit, and found the Worthington website (little to no info there.... hmmm):

http://www.worthingt...cuba_tanks.html
(the XS Scuba link has the specs on the HP tanks, as well as the LP series)

My PSTs still look new, no scars or rust. I'm very satisfied. I *do* like the optional convertible Thermo valves that folks are offering now. If more shops went to them when they replaced their rental tanks, I'd be a happier camper. I've had more than average problems with the O-rings on rental yoke tanks. Big sigh. I'd rather have the responsibility for the main H-P O-ring since I replace mine regularly. It'd also reduce all the swapping back and forth between the DIN and yoke connectors on my main reg. One of these days, I'm gonna screw the threads up in the reg body.

[scubafanatic]

Hi Desert_Diver,

...well, there was quite a lengthy discussion on Worthingtons
expected 'durability' relative to PSTs...all the ins-and-outs of various
galvanizing methods........from what I remember, while the PSTs ARE
hot-dipped-galvanized, the Worthingtons ARE NOT, they employ another
galvanizing technology.....and my 'read' on it was that while the PST
method is superior, Worhtington feels that their galvanizing method,
combined with protective paint, gives them a product that at least
matches PST.

......you're certainly right about painted tanks looking like 'heck'
with time.......trashed paint doesn't affect AL tanks performance, but
it spells eventual death for 'steelies', especially in a salt-water environment.

.......last year OMS/Faber were to introduce what I'd call the 'perfect' tank
LP steelies with the PST-style hot-dip-galvanizing......I'd have killed for
those tanks! .......but it never materialized.......heck, OMS has even
totally dropped Faber LP steelies and now only sells the PST HP steelies.

I do welcome Worthington into the market, if for no other reason than
to take some of the market pressure off the pricing/availibility of the PST
tanks.......a PST monopoly wouldn't benefit the diving consumer.

I agree about those convertible Thermo valves...pretty 'slick'......they're
becoming a lot more common and with time will pretty much replace
the yoke-only style.........Beuchat even makes a pretty cool 'convertible'
Y-valve......I've installed those on (6) of my tanks so far...they're not cheap
but they're a fantastic design/product....let's me dive my 'doubles' regs
on a single tank with no modifications.

....by the way, have you tried the ScubaPro DIN/Yoke screw-on DIN/
Yoke adapter? I leave my regs as DIN 1st-stages for the 'techie' stuff, but
on a tropical dive trip with AL80's, I simply screw on the adapter so they'll
fit on a yoke-valve tank......it's takes about 2 seconds....very easy!

Karl

[fbp]

I agree about those convertible Thermo valves...pretty 'slick'......

Huh?? is there website on these.. never heard of them (not that that is unusual) but what are they???

....by the way, have you tried the ScubaPro DIN/Yoke screw-on DIN/
Yoke adapter?

I think I'm using the ones you're talking about, not sure if they're scuba pro or not... but I have them on 8 tanks (4-faber 120s and 4-PTS HP119) has them, din on the tank for normal use, but if I have to swap out my back up reg (yoke) or go on a trip (car to canada) and the dive shop/boat does have the DIN adaptors, I just screw them in, works fine. Starting to collect a lot of the screw in adaptors now, so just carry them in the dive kit.

Yoke?, only used it a few times, no problems that I recall... Seems to work fine, prefer the DIN, but nice to be able to covert as the situation occures.

Had one (dragging this on) as an example:
Nooka Sound, Vancouver Island, 1 hour trip on a dirt road 45 min by boat (out in the wild wild west), brought my tanks (Faber HP120 DIN-adaptable) and they couldn't fill them. I had the valves, just didn't think they needed them. On the boat out to the next day's dive, was told so, offered Alum 80s which threw my weighting off, underweighted (or something like that don't remember exactly what it was - not enough to get down, dry suit start leaking as no pressure to seal on the inside etc..) on 1st dive, no additional weight available so ruined the day.

Anyway, they work, I'm glad I have them. You all are probably aware of it, but the DIN valve for those covertables are shorter in depth to make the seal with the yokes/plugs.. so it's not the Deep threaded DIN valve... I didn't know that....

on to the next one...