Stupid question time

[Piro]

I am looking at buying a tank. Here is the stupid part.

Is HP or LP the way to go. I currently do not have a DIN Reg setup so i would ahve to do that. But at the end of the day i ask my self is there a chance of me setting up dpubles, my answer was yes. But when i finally get around to that do i set up 2 HP's or 2 LP's Theses are both steels by the way, i researched that much and i know the differnce between an HP and LP but if i want to set up doubles how should i go about that.

And also what is the shopping list for setting up doubles.

Im sure this has been posted a few times and a quick search would have found it but, im in a hurry to get to a family event so i did not have time to sort though all the posts.

Thnx Guys,

Piro

 

[ronbeau]

I am looking at buying a tank. Here is the stupid part.

Is HP or LP the way to go. I currently do not have a DIN Reg setup so i would have to do that. But at the end of the day i ask my self is there a chance of me setting up doubles, my answer was yes. But when i finally get around to that do i set up 2 HP's or 2 LP's Theses are both steels by the way, i researched that much and i know the difference between an HP and LP but if i want to set up doubles how should i go about that.

And also what is the shopping list for setting up doubles.

I'm sure this has been posted a few times and a quick search would have found it but, I'm in a hurry to get to a family event so i did not have time to sort though all the posts.

Thnx Guys,

Piro

I am not qualified to answer you question about doubles but I can answer you DIN versus yoke question.

Many of the HP tanks come with a combination valve that will accommodate either a yoke or a DIN regulator.

My HP 100s (Worthington) comes with a Thremo Pro valve which by default accommodates a yoke style regualtor. If you want to use a DIN regualtor you simply use a hex key to unscrew the insert that accommodates the yoke regualtor. Once the insert is removed you have a DIN valve that works with a DIN regulator.

The HP cylinders usu sally have a working pressure of 3442 PSI which allows them to be used with either a DIN or yoke regulator.

I believe a working pressure of 3500 PSI or above requires a DIN regulator to be used.

 

[Jimmer]

Ronbeau is on the money as far as the convertible valve go. My suggestion is if you want to go doubles someday, get your regs converted to DIN. I have talked to a lot of tech instructors that won't teach you unless you use DIN for all your regs. If you can get 3500 PSI fills easily, get the HP tanks. I have a set of LP 108's, my instructor uses HP 100's, and my doubles are around 15 to 20 pounds heavier than his. That's a big PITA dragging to and from the boat and back into the boat. If you want to go doubles in the future, make sure the tanks you buy now are ordered for a matched set, or if they are in stock, have them measured to be sure they match. Aside from that you just need bands and a manifold, and you're set to go to doubles.

 

[DA Aquamaster]

There are two flavors of DIN valves - 200 bar (actually 232 bar/3480 psi) and 300 bar. The 200 bar DIN valves have 5 threads and are short enough that with an insert screwed in them they can be used on regs with yoke connections. They are usually sold this way with the insert in them as a convertible DIN/K valve.

300 Bar DIN valves have 7 threads and are too long to fit inside a yoke at all. 300 Bar valves are "needed" for pressures of 3500 psi and over, although this standard has been adopted primarily to prevent prevent damage to regulators that may not be designed for pressures of 3500 psi or greater, not because a 232 bar DIN valve would fail at 3501 psi. In effect, a reg with a 200 bar DIN connection will not seal in the deeper 300 bar valve. But a reg with a 300 bar DIN connection will seal in the shallower 200 Bar DIN valve.

The LP versus HP argument really depends on the specific tanks you are discussing. The PST and worthington E7 series are very good choices offering large capacity with low weight and with a pressure of only 3442 psi - still 232 bar DIN/K valve territory where you could stay with yokes now and go to DIN later. The E7-100 for example gives an honest 100 cu ft at 3442 psi in a package that is the same diameter but 2 inches shorter than an AL 80, is 1 lb negatively bouyant when empty and weighs only 33 lbs, meaning that when tank weight and lead weights needed for bouyancy are considered, you are carrying about 4 lbs less total weight up the ladder than if you had an AL80 - 8 lbs less if you compare double E7-100's to double AL80's.

 

[Web Monkey]

FWIW, it's easier to get a good fill with LP tanks. Almost any shop will be able to deliver 2640PSI. However, HP tanks are smaller for a given air volume.

The bouyancy change between empty and full for any tanks of the same volume is identical, regardless of their pressure rating or construction. For example, an Al 80, HP steel 80 and LP steel 80 would all have about 6.5 lbs buoyancy change between full and completely empty.

Is HP or LP the way to go. I currently do not have a DIN Reg setup so i would ahve to do that. But at the end of the day i ask my self is there a chance of me setting up dpubles, my answer was yes. But when i finally get around to that do i set up 2 HP's or 2 LP's Theses are both steels by the way, i researched that much and i know the differnce between an HP and LP but if i want to set up doubles how should i go about that.

 

[CompuDude]

If you're buying new tanks, it's likely they'll have convertible valves (DIN and Yoke combo), so that's not a factor in the decision. If you double up your tanks, you'll be replacing the valves with a DIN manifold anyway.

As for HP vs. LP, I prefer HP because they are easier to carry around... they're a lot lighter than LP tanks, and smaller. The important question, however, is what kind of fills are readily available in your area. If your local shops have a hard time giving you good fills, it makes a lot of sense to get LP tanks that will be easier to get filled. If they all have good compressors, however, HP tanks are the way to go, IMO.

 

[Piro]

well i talked to the LDS and they are less than thrilled for me to buying tanks online, but, what can they do, tehy cant touch scuba.com's price.

they also told me today that LP would be they way o go simply since i dont live in a prodominately diving area, it would take a while to fill a HP tank.

Ok so people my new todo list--

1. Buy the tanks! ? Anyone found of any particular brands? Im looking at getting a 119 or 100 i havent decided yet.
2. What id hte other stuff i need! And does anyone know who makes goo back plates?

 

[CompuDude]

well i talked to the LDS and they are less than thrilled for me to buying tanks online, but, what can they do, tehy cant touch scuba.com's price.

they also told me today that LP would be they way o go simply since i dont live in a prodominately diving area, it would take a while to fill a HP tank.

Ok so people my new todo list--

1. Buy the tanks! ? Anyone found of any particular brands? Im looking at getting a 119 or 100 i havent decided yet.
2. What id hte other stuff i need! And does anyone know who makes goo back plates?

100s are a LOT lighter to carry around than 119s.

Although 100s and 119s are HP sizes. You'll be looking at LP85s or LP95s for the same size tank.

If you're diving salt water, I prefer galvanized tanks for increased rust resistance. So look at Worthingtons. If you're diving fresh water, Faber's are great. (Either will work well in either place, but that's how I would vote)

 

[NorthWoodsDiver]

Go with HP tanks cause worst comes to worst even a moderate pressure fill like you would get on a aluminum 80 (3000psi) will give you 80 cuft on a 100 cuft hp tank and be much lighter than their low pressure cousins.

You need to decide wether you are gona dive true doubles or independent twins. Both have a place but most people prefer banded doubles with isolation manifolds over independent twins.

If you are going with true doubles I would go here: http://www.diveriteexpress.com/gas/spdoubles.shtml

That package will give you all the necessary parts at a good price. I personally an going for the X7-100's for $999.95

as for your question on back plate manufactures I would highly recommend FredT but he doesn't have a website. He is the cheapest I found and offers the widest variety. Other than him you can go with OMS, Dive Rite, DSS, Halcyon, Oxycheq, Golem, or many others. I really like FredT's plates, he is on scubaboard but not often so its best to email him. PM me for his email

 

[Colliam7]

well i talked to the LDS and they are less than thrilled for me to buying tanks online, but, what can they do, tehy cant touch scuba.com's price.

Interesting. Looked at the scuba.com prices and they are not dramatically lower than prices I have seen at my own LDS for steel tanks. (Part of that lack of difference may be that they offer 'Free Shipping', which is anything but free for weighty tanks.) It seems a bit surprising that they would not be able to come closer (i.e. within $20-$30/tank) than your post indiciates, but that is their business decision, I guess. Scuba.com offers XS Scuba steel tanks, as well as Faber. You may want to get comment from those who own the XS Scuba tanks, about their experience. (I am more familiar with PST and Worthington, and would like to know if others find the XS tanks durable, etc.) The 119s are a nice tank, BTW.