Traveling Manifold?

[it_mike]

OK, here's the concept...

We've all seen the travel doubles velcro rigs, but what about a removable manifold?

I'm thinking a yoke to din adapter, connected to a tee. The tee hosts a din port, and the isolator bar.

This would allow us to rent singles, and dive doubles. Thoughts?

Mike

 

[qrpc]

A solid manifold could be put under a lot of stress if the cloth straps allowed the tanks to shift. There is no reason why you couldn't rig a flexible manifold if you could obtain hoses that can handle sufficient pressure and volume. (standard hp hoses might have too narrow an internal diameter, but that is just a suspicion.)

There might also be some other ways that work, but the big question is whether the rig would be safer than just diving independent doubles.

 

[DA Aquamaster]

Halcyon uses a flexible manifold on the RB80 that works fine.

I am not clear about what you mean when you describe your manifold. Do you mean a T on each post with an isolator in the middle? If so it would basically be an updated DIN and isolator version of a "cheater bar" - an idea that fell out of favor in the late 1970's. As qrpc suggests it would be difficult to see any real advantage over independent doubles. It would add complexity and only save you 2 reg switches during a dive.

A regular HP hose would not support the flow rate needed at depth so you'd need a custom hose with larger internal diameter.

 

[diversteve]

There's a company in my area (can't recall the name now) that sells what is basically two tank fittings connected via braided steel line to a single yoke. The idea being that you rent two tanks, get a set of OMS Travelbands (or others) and dive what are in effect dependent doubles. No valve switches required. Both valves are machined out of a block of metal so are pretty substantial looking. The whole thing in a little pelican case was about $450 as I recall.

Here's an example of a "cheater bar" manifold similar to that mentioned above: http://www.scubaboard.com/forums/ge...86-fs-vintage-dependent-doubles-manifold.html

The problem with it was that I didn't think it would work with travel bands.

 

[it_mike]

I'm thinking similar to the cheater-bar, but with two rigs and the iso valve. Solid tank bands would work, instead of the cloth straps...

My goal would be dependent doubles, using rental tanks, while traveling. While I could run independent doubles, I just like playing with ideas.

Thanks,
Mike

an updated DIN and isolator version of a "cheater bar"

Exactly! I thought I remembered these things.

 

[DA Aquamaster]

Bascially what you would want then is a Yoke to DIN adapter with a port in the side for a flexible hose leading to an isolator valve then to a similar Yoke to DIN adapter that would attach to the other tank valve.

If you leave the tank valves facing each other (like the old cheater bars) you have the knob for the right post facing forward and the knob for the left post facing aft and I am not sure where you would put the DIN connection and first stages.

If you face both valves forward, then the left post is inside and hard to shut down - like it is with independent doubles, unless you use a left hand modular valve - not likely on rental tanks.

You could face the left hand valve backwards, but that causes potential hose routing issues and places the fisrt stage in a position where it is more likely to snag or be damaged.

The potential flaw with any of the approaches is the yoke connection on the valve - if one comes loose due to an impact, etc, you will need to use that isolator valve.

The concept works better with 200 bar DIN/K valves where you could use a connector where the male end screws to the DIN/K valve (with insert removed) and then provides the port for the flexible hose to the isolator and also provides a female DIN fitting for the first stage. it would have the same donwside as Yoke to DIN adapter of causing the first stage to protrude a bit farther toward your head.

Also, you only need flexibility on one side of the isolator. You could design the cross bar to be hard mounted to the right valve connection with a pig tail from the left side of the isolator to the left hand valve connection. This would prevent issues with trying to close an isolator mounted in the middle of a rubber hose and would reduce the number of connections. Grabbing the isolator and lifting the doubles would however be very bad news with this arrangement, but is would easily address issues with different tank spacing.

 

[Gerbs]

Late addition to the thread with an out-of-the-box thought:

Link the two 1st stages using the HP ports with a Swagelock or similar HP valve in the middle? Use standard HP hoses. Clip the valve to a convenient D-Ring for access and away you go.

You are completely independent of: tank size, valve shape, valve type and tank mounting

The flow restriction is going to make cross-feeding from one tank to the other reg possibly breath harder at depth, but I'm not sure I'd want to risk having an unrestricted HP port and a soft connection. Also, you need to turn off the tank and the cross-feed if one regulator free flows, instead of just the regulator.

Gerbs

ps. Mares used to sell an MR first stage to link into the LP of the primary first stage to overcome stage failure, but this only covers 1st stage malfunctions and cost the same as a 2nd set of regs, so it wasn't popular.

 

[qrpc]

Late addition to the thread with an out-of-the-box thought:

Link the two 1st stages using the HP ports with a Swagelock or similar HP valve in the middle? Use standard HP hoses. Clip the valve to a convenient D-Ring for access and away you go.

Can hp ports provide a high enough flow rate?

 

[WD8CDH]

Can hp ports provide a high enough flow rate?

In most cases, "probably" at recreational depths. An SPG hose end will not unless drilled out.

What DA Aquamaster described is probably the best choice for rental tanks, assuming you have DIN regulators.

 

[Gilldiver]

Is this close to what you are thinking about?


http://www.scubaboard.com/forums/vi.../307506-poseidon-doubles-din-phoenix-ram.html
It dates from the 60's and connects two DIN tanks together. Using a Cam Band system, you should end up with a real ridged system. Some might not like the reserve valve.