Explanation on what's required for Doubles

[MKrauter]

Hello everyone,

I am considering moving into doubles over the winter so that I will be able to get some experience in them before my GUE-F class next May. I am thinking about starting with double AL-80s, since I've already got one and they seem like a suitable size for recreational dives to start as well as moving into more technical dives in the future. Mainly I hope to use these to gain experience before I move into something bigger like LP95s or LP104s. Please not that cost is the factor limiting me from jumping right into steel tanks.

I am trying to figure out all that is required to make the switch and have gotten some prices concerning regulators and tanks. However, I am not at all familiar with the bands, manifolds and valves required for doubles.

Currently my AL80 has a yolk valve which I plan on swapping with a left handed DIN valve. I know that my LDS sells new AL80s with a yolk/DIN valve (with the spin-in converter). However, when doubling tanks, is there a specific valve that you need to fit the manifold into the equation?

Concerning manifolds, what is a good "brand" or does it matter? Is there any I should really be looking out for? My LDS is an OMS dealer (which the owner has recommended against) DiveRite, X-S Scuba, and Scubapro (these are the companies that I am fairly certain manufactures manifolds). Any features I should look for or are they all more or less the same?

Concerning bands, again any companies I should look out for or features? I know I nee a 7.25'' bands for AL80 but do LP95s or LP104s require the same size as well?

Thanks for the help!

M.

 

[DevonDiver]

Any features I should look for or are they all more or less the same?

Valve handles should be rubber (plastic can crack and be unusable if hit)

Do check the number of rotations open-closed. Valves can vary between 6 and 20 (?). Makes a big difference with speed of shut-downs.

 

[Doppler]

Go sidemount! LOL

 

[Scuba.com]

Hi MKrauter

Manifolds usually come with the correct left and right handed valves specific to the manifold itself, so if you're planning on buying tanks to set up as doubles, you may want to buy the tanks without any valve, and you may save a few bucks. Tanks usually "come with" a valve, and really, that's built into the price, so if you don't want the valve that comes with, you can probably save a little... you know?

Also, If your plan is to dive the steel tanks, then why not just get what your plan is, instead of getting something that you're going to end up not using after a few months??

 

[nimoh]

Hello everyone,

I am considering moving into doubles over the winter so that I will be able to get some experience in them before my GUE-F class next May. I am thinking about starting with double AL-80s, since I've already got one and they seem like a suitable size for recreational dives to start as well as moving into more technical dives in the future. Mainly I hope to use these to gain experience before I move into something bigger like LP95s or LP104s. Please not that cost is the factor limiting me from jumping right into steel tanks.

Aluminum 80s will be just fine for a GUE-F class..actually that's what I used. However, they tend to be very light in the tail end and this can affect your trim at the end of the dive. If you need to add a bit of weight in this configuration, a good place would be in the form of a tail weight hanging off the bottom tank band bolt.

I am trying to figure out all that is required to make the switch and have gotten some prices concerning regulators and tanks. However, I am not at all familiar with the bands, manifolds and valves required for doubles.

Currently my AL80 has a yolk valve which I plan on swapping with a left handed DIN valve. I know that my LDS sells new AL80s with a yolk/DIN valve (with the spin-in converter). However, when doubling tanks, is there a specific valve that you need to fit the manifold into the equation?

Concerning manifolds, what is a good "brand" or does it matter? Is there any I should really be looking out for? My LDS is an OMS dealer (which the owner has recommended against) DiveRite, X-S Scuba, and Scubapro (these are the companies that I am fairly certain manufactures manifolds). Any features I should look for or are they all more or less the same?

A manifold is composed of three main pieces. Left valve, right valve and crossover. So, when you buy your manifold, you will be replacing that yoke valve anyway. If your current aluminum 80 was sold for single tank use, it is unlikely that it has an outlet for the crossover. IMHO your best bet is to buy a manifold. I don't know much about the different brands, I have used Thermo and Halcyon and have no complaints about either of those (except that the Halcyons are no longer being made).

Concerning bands, again any companies I should look out for or features? I know I nee a 7.25'' bands for AL80 but do LP95s or LP104s require the same size as well?

Yes, you will need 7.25" bands for you aluminum 80s, but both LP95s and LP104s will require 8" bands. The manifold is the same since 8" bands bring the tanks a little closer together to make the valves the same distance apart regardless of 7.25" or 8" bands.

 

[DevonDiver]

Go sidemount! LOL

Might not prove too popular if turning up for a fundies course (yet-a-while...)

BUT... definitely good advice if happy to progress outside the GUE fold.

 

[Jim Lapenta]

Nothing wrong with an OMS manifold or bands if he has them in stock. XS scuba will work as well. And likely be a little less than the Dive Rite. SP I'd stay away from as you are going to pay a premium for no real return on it.
I have a set of LP 85's I have decided to break down into sidemount tanks. Probably by the end of the year. Dive Rite 300 bar manifold and 7.25 inch bands. I may do it sooner if you have the cash now. LP 95's or 108's require 8 inch bands. Have a set of those as well for my LP 95's that I have decided will only see use as singles for student deep dive course tanks or sidemount. I have the crossover bar for them as well and could be talked into selling the whole manifold assembly as well. I have valves to replace the ones I'd remove to make another full manifold assembly (200 bar). If you are interested in any of this shoot me a pm. Find out what your LDS wants and I'll see what I can do on my end. You might end up with enough to do your 80's and have a set of bands for the 95's for less than what they want for the stuff for one set. Or just a bit more and be able to have both.

Sent from my DROID X2 using Tapatalk 2

 

[elan]

Double AL80 are good starting point especially if you already have one. They are long and positive so give you a flexibility in terms of trimming them. I would not buy steels until you figure out what type of diving you are going to do as there are many factors. I would definitely not want jumping over rocky beach in a set of double 104 full of nitrox.

Manifold wise I would get Halcyon if you can still get a hold of one. Then Dive Rite. Im not sure if OMs has changed but they used to have face type orings on the crossbar whick is not highly regarded by technical divers - an plastic small knobs.

 

[FoxHound]

Have a talk with the instructor you plan on using, they will be able to give you a good rundown of what you need for gear especially considering that GUE courses require a very specific kit list. You can find it on the GUE website. That being said, if you are planning on moving to either of those 2 sets of steel tanks you mentioned, you will require an 8in set of bands instead of the 7.25 needed to band alu 80s together.

As for manifolds, like was already mentioned, you generally don't buy all the parts separate, you buy the manifold as a whole (ie left hand, right hand, and isolater all in one). When I was diving doubles i really liked the sea elite manifolds. Like Doppler has suggested, I went sidemount and all was much better in the world.

Don't forget you need a bp/w combo( sometimes a different size wing for steels and alu tanks depending on their buoyancy), can light, backup lights etc as per the gue kit list.

 

[Doppler]

Might not prove too popular if turning up for a fundies course (yet-a-while...)

BUT... definitely good advice if happy to progress outside the GUE fold.

We do what we can, Andy... LOL.


How are things there in god's country?