Second stage connection

[AfterDark]

Yes. It requires only a second 11.420.102 hose connection installed in place of the blank plug on the other side of the case.
View attachment 674596
Part #5 above.

Where pray tell can this part be obtained? I just checked those are expensive regulators! I'm not sure if I can afford Part #5!?!

 

[happy-diver]

Ultra Magnificent!

 

[AfterDark]

Ultra Magnificent!

You like my concept or you yanking my chain? I've seen some of your creations and was impressed as well as inspired.

My next dive I'll the AIR as a primary to make sure it works well.

 

[rhwestfall]

You like my concept or you yanking my chain?

We never know with happy....

 

[Angelo Farina]

So my concept is as follows:

Different idea for independent doubles

One of the drawbacks of independent doubles (IDs) is the regulator changes. Removing a regulator from one's mouth at 100+ feet is something that some people might advise against.

It can also create the false impression that you may be in trouble. A DM once told me post dive that when he saw me drop my regulator from my mouth @130FSW he began moving towards me thinking I may be narc'd and in need of help. He came over to me after the switch and gave me the OK sign which I returned not knowing why at the time. Anyway, I'm going to rig a configuration that eliminates the regulator switches while using my IDs. It could also be used with sidemount.

Gear needed is a second stage that can be connected at the same time from both the right and left ports, 2 on/off inline valves, 2 90 degree elbows, and 2 40" or to suit LP regulator hoses for BM (SM would be shorter); also 2 1st stages with identical IP's. Also 2 overpressure reliefs one for each 1st stage. Since only one second stage is used, a second 2nd stage is mounted on the right hand 1st stage for an octo. For complete redundancy an AIR type inflator can be added to give the diver a third 2nd stage option .

The left side 1st stage is connected to the left side of the 2nd stage by the elbow assembled with the on/off valve . The right tank is connected to the right side of the same 2nd stage the same way. The 2nd stage is necklaced and the LP hoses are routed under the arms. Tank switches are made by turning the inline valves on and off instead of switching regulators.
There maybe a slight reduction in redundancy but the diver still has 2 second stages that can access either tank thru separate 1st stages so the reduction is slight.
The on/off valve and elbows can be seen as weak points but after using both for 5 years without issues, I have confidence in their reliability. Here are some pictures:


View attachment 674576 View attachment 674577 View attachment 674578

This is a very interesting idea, with some similarity with the Pilot setup which was used by my friend Marco at the end of seventies.
He was using a manifolded twin tank with reserve.
Two MK5 first stages and two LP hoses to a single Pilot, which in practice was necklaced directly by the hoses. Plus a 109 on the right MK5 and the BC hose on the left MK5.
Those old MK5s had only two LP ports each.
His setup was simpler, no swivel, no in-line valves, a single SPG as the two tanks were permanently connected.
I will think about your requirements and see if I find a simpler approach which satisfies your requirements (independent doubles, management of air from the two tanks without reaching the main valves behind your head, redundancy, etc.).
Perhaps a side mounting could be better?

 

[johndiver999]

Looks interesting. It also looks heavy in your mouth.

If one of the shut off valves fails, can it leak out air coming from the other side? In other words, if one shut off valve fails, does the whole system become a problem?

It looks pretty simple to dive.

 

[AfterDark]

This is a very interesting idea, with some similarity with the Pilot setup which was used by my friend Marco at the end of seventies.
He was using a manifolded twin tank with reserve.
Two MK5 first stages and two LP hoses to a single Pilot, which in practice was necklaced directly by the hoses. Plus a 109 on the right MK5 and the BC hose on the left MK5.
Those old MK5s had only two LP ports each.
His setup was simpler, no swivel, no in-line valves, a single SPG as the two tanks were permanently connected.
I will think about your requirements and see if I find a simpler approach which satisfies your requirements (independent doubles, management of air from the two tanks without reaching the main valves behind your head, redundancy, etc.).
Perhaps a side mounting could be better?

Thanks I tried sidemount with a factory rep some years ago and wasn't impressed at all it's a non-starter for me. I don't like a slung19 cuft pony never mind real tanks on my sides! I don't need over head clearance which is why SM was invented 30-40 years ago in the caves. It's a "new" thing these days, what old is new again.

The setup in the picture will work fine for me. I've been using everything in those pictures regularly with an ID config with 2 156's. I'm just dropping the 156's and replacing them with AIR 2nd stage.
The basic setup has proven itself over the years as safe and reliable.

 

[AfterDark]

Looks interesting. It also looks heavy in your mouth.

If one of the shut off valves fails, can it leak out air coming from the other side? In other words, if one shut off valve fails, does the whole system become a problem?

It looks pretty simple to dive.

no, they are independent from each other only connected to 1 2nd stage. The other tank could be used to end the dive. I had that same thought but it is suprising lite, of course my regular regulator is SP 156 chromed brass so that's no lightweight either. I think the plastic body compensates some.

 

[Open Ocean Diver]

Thanks I tried sidemount with a factory rep some years ago and wasn't impressed at all it's a non-starter for me. I don't like a slung19 cuft pony never mind real tanks on my sides! I don't need over head clearance which is why SM was invented 30-40 years ago in the caves. It's a "new" thing these days, what old is new again.

The setup in the picture will work fine for me. I've been using everything in those pictures regularly with an ID config with 2 156's. I'm just dropping the 156's and replacing them with AIR 2nd stage.
The basic setup has proven itself over the years as safe and reliable.

Just curious what would happen if both LP switches were closed at the same time?

 

[Angelo Farina]

Do the tanks drain equally or does one drain faster than the other?

If both valves are left open, one tank will empty slightly faster than the other, as it is impossible to tune the two first stages exactly the same.
This can be a problem or bot.
For me it would not be a problem, provided that one has two SPGs and checks the two pressures often.
When one tank is empty the other will continue supplying air.
In my opinion those two inline valves are superfluous...
The sustem will still be more redundant and safer than using a standard AL80 with just a single valve and a single first stage...
Un fact I am not happy with such a basic setup.
I use a 15 liters steel with double valve and two DIN first stages (MK5) and two second stages (a 109 on the right and a 129 on the left).
Which in the ends provide more or less the same degree of redundancy as the system with an Air1 with two hoses described here.