AquaLung Octo Freeflow Question

[Lil' Irish Temper]

Alright, I have a new AquaLung Titan LX and the Titan/Calypso Octo.

Both are brand new, and the woman and I were swimming around down at the local pool, and the stupid Octo. is a free-flowing machine. Those of you who have the adjustable regs. know there is a + and - sign on them. Anyways, when it was free-flowing I turned it all the way to - which according to the instructions is what you are supposed to do to reduce free-flow, but this thing keeps free-flowing. So if I turn it all the way to +, it stops, not one bubble.

Am I reading the instructions wrong, or do I have one that something is screwed up in?

- to reduce free-flow, and + is suppose to deliver more air right?

It breathes fine. I'm just confused. When in doubt, just go slam it on the concrete a couple time to make things fit better.

 

[xSandman3]

The Titan LX first stage is balanced, if not over-balanced, and the octo is unbalanced. It's not designed to work with the LX, you need the LX octo. I went through the same thing using the standard Titan first stage and an Aqualung LPO...leaked like crazy all the time.

 

[DA Aquamaster]

Whether the first stage is balanced, overbalanced or unbalanced will not make a difference if the octo is properly adjusted and tuned to the specific first stage. In short, an unbalanced octo has to be tuned to accommodate the maximum intermediate pressure that will be encountered, but this is no big deal.

The +/- adjustment basically changes the position of a flow vane in the second stage. When it is on (-) it creates back pressure that pushes the diaphragm back out and stops the freeflow. When it is in the (+) position it directs the air out the mouthpiece which reduces pressure in the reg and keeps the diaphragm depressed which cause the air to continue flowing.

So you do not need a new LX Octo. The Calypso octo will work fine once you have a tech adjust it to work properly with your first stage.

The LX octo is air balanced and could potentially be adjusted to breathe with a lower inhalation effort than the Calypso octo but it is not a required upgrade.

 

[keyshunter]

The Titan LX first stage is balanced, if not over-balanced, and the octo is unbalanced. It's not designed to work with the LX, you need the LX octo. I went through the same thing using the standard Titan first stage and an Aqualung LPO...leaked like crazy all the time.

I hope it wasn't an Aqua Lung dealer who fed you that baloney. The Titan first stage is indeed balanced. The LX second stage is balanced, and the regular Titan second stage is unbalanced. Identical Titan first stages are used on both LX and regular Titan (also Titan Micra). Any of the AL octos, balanced or unbalanced, if properly adjusted, can be used with the Titan first stage.

 

[gehadoski]

DA Aquamaster your analysis for the solution was really amazing. But I don't think that the adjustable (+/-) create as much pressure to push the diaphram because it is still flowing through the mouth piece.

 

[Lil' Irish Temper]

But why would it quit when I turned it all the way to the +, that's what I don't get? That is totally backwards. Only thing I can come up with is like DA said "it needs adjustment"

DA, I'm going to South Dakota this summer. Black Hills, any diving out there?

 

[DA Aquamaster]

DA Aquamaster your analysis for the solution was really amazing. But I don't think that the adjustable (+/-) create as much pressure to push the diaphram because it is still flowing through the mouth piece.

Let me try to explain it again and expand on it as I think you are making an incorrect assumption about what I am saying.

When the flow vane is in the (+) position it creates a venturi effect by accellerating the airflow directly out the mouthpiece which lowers the presure in the case, which in turn sucks the diaphragm in and depresses the lever causing the air to continue to flow.

With the flow vane in the (-) position, the flow vane does not direct the air directly out the mouthpiece so a positive pressure is maintained inside as the air swirls around inside the case before finding it's way out the mouthpiece which tends to try to press the diaphragm out and lets the lever close the valve stopping the air unless opther action is taken to keep the lever depressed such as depressing the purge or inhaling from the reg.

Stopping the airflow entirely is not required as all that really needs to occur is to redirect some or all of the air before it exits through the mouthpiece in order to increase the pressure in the case so that it is slightly higher than the cracking effort of the poppet assembly - 1.5 inches of water would normally be enough positive pressure.

So, adjustable flow vanes are designed to control and stop large freeflow and they work just fine when they are properly installed. One of the things the tech should check is whether the flow vane is properly installed and operating correctly.

On the other hand a flow vane will not stop a slight freeflow caused by improper orifice adjustement as the flow rate is normally so small that a venturi effect does not occur. Second stages with an adjustment knob that allows the spring tension in the second stage to be increased will often be able to compensate for a mis-adjusted orifice, but that is an entirely different adjustment.

 

[xSandman3]

Thanks for clearing this up for me as well. I just know that the LPO I had freeflowed all the time. When I had it adjusted to stop leaking, I could barely breathe off of it. My wife had the same setup as me, and had the same problems. I replaced them with the Calypso/Titan octo, and they work great now.