Double tanks on my BC

[copter53]

If I were to use independent doubles as shown in one of the first pictures. How would I integrate both of them into my one computer? Or will I have to get an extra computer as well with the extra reg. When I exhaust one tank and switch to a 2nd tank that 2nd tanks computer will not account for my air consumption during my use of the 1st tank?

It just seems like using a center post manifold is cheaper as I can use my one reg set with no extra purchases and I would not have to worry about a 2nd o-ring busting or anything? Since I am fine with diving on a single tank with no redundancy. Whats the problem diving with two tanks with no redundancy?

Also, Since I don't own tanks and will be renting. How could I apply the center piece manifold to rental tanks?

 

[Anti-Hero]

If I were to use independent doubles as shown in one of the first pictures. How would I integrate both of them into my one computer? Or will I have to get an extra computer as well with the extra reg. When I exhaust one tank and switch to a 2nd tank that 2nd tanks computer will not account for my air consumption during my use of the 1st tank?

You can just use a separate SPG on each tank, assuming each is using the same gas. You will also want to only consume 1/3 from the first tank, then switch, and then use 1/3 from the second, then switch, etc., etc. This way you always have a redundant source of gas.


It just seems like using a center post manifold is cheaper as I can use my one reg set with no extra purchases and I would not have to worry about a 2nd o-ring busting or anything? Since I am fine with diving on a single tank with no redundancy. Whats the problem diving with two tanks with no redundancy?

Single tank, double tanks with a single post, and double with an isolation manifold all have their positives and negatives.

Also, Since I don't own tanks and will be renting. How could I apply the center piece manifold to rental tanks?

You most likely will not be able too.

 

[Gombessa]

Another solution would be to use a Z system manifold (found here):

UTD Online Store - +1 206 321-0870 - sales@utdequipment.com

This allows two tanks to be connected to the block which then supplies one set of HP and LP hoses. It does require two first stages though.

I've never used a Z manifold, but from speaking to those who have, this isn't how it works. I understand the block is low-pressure only, so 1) it doesn't supply HP pressures, 2) it doesn't support HP hoses, and 3) because it is LP, it has very significant considerations to note if you intend to use it with multiple tanks (i.e., you cannot simply hook it up to double tanks and expect it to deliver gas from both). Hopefully someone more familiar with the system can comment and clarify.

 

[spectrum]

I want to dive with doubles purely because I want more air time. I understand they are heavy and whatnot. Thats why the most ideal situation is to be able to just bust out that "crossover manifold" w/e I feel like using doubles. I don't want to buy my own tank and have a 120 cu that will always be 120 cu. What if I just want to do a short dive then the 120cu will be overkill. Yet, if I am able to use two 80 cu's at the same time that would be epicality. What are the potential problems with a crossover? Is it not reliable or what?

Looking through your posts it's not clear what your driver is other than wanting occasional extra air. Looking at your profile and question I have no idea what your experience is of even if you are a certified diver.

If you are new and tend to come up short on air more diving and technique refinement is job 1. Layering more gear isn't the answer.

If you simply need a flexible way of carrying air for diversified dives there are tried and true ways of doing this. In selecting a configuration you really need to understand the difference between capacity which may be satisfied by a stage bottle (that may not always be with you) or big cylinder and redundancy that provides independent systems.

There is only so much you can do with a conventional BC. I would not bother trying to go past one cylinder of back gas on the probe. If nothing else the accessory cost would be a good down payment on a correct solution.

The best solution I can see is to forget about any sort of hard manifold. A manifold is a structural element but it needs to be complemented by bands to prevent stress and provide a mounting means. Banding and re-valving rental cylinders isn't going to happen.

Independent regulators are a simple solution to the air delivery side of the equation. They give you redundancy and can be used with any combination of cylinder sizes. Single, Single with pony, single with stage, doubles, take your pick.

For the mechanical or mounting aspect you may need several gadgets. You already have a BC for singles diving. To get to the other extreme you might consider the OMS travel bands on a plate & wing sized for doubles. The travel bands are cam band straps, like your BC that connect to a plate interface.This will let you buckle on a couple of full sized rental cylinders in a snap, hang your regulators and go. From there you can rig pony and stage slings as desired when you want to augment a single cylinder.

You are obviously cutting your teeth on this. From what I read getting a second regulator (1st, 2nd, SPG) and a pony sling may be the cheapest first step towards your goal. The regulator has universal use and the sling can be $10 worth of marine hardware store junk.

Pete

 

[spectrum]

If I were to use independent doubles as shown in one of the first pictures. How would I integrate both of them into my one computer?

just say no to integration. Let the computer do what it needs to do, manage nitrogen and perhaps oxygen loading. Plan your gas and dive your plan. Keep it simple. Even when integrated you need to be doing this anyhow.

Pete