Is the airlink a balanced reg?

[redacted]

From the Leisurepro description: "The Octo-Z is a Dependable Downstream Demand Valve Design Breathable Inflator. The Octo-Z has a Balanced Inflator Valve Design...."

This appears to be a copy of a Scubapro Air2 which uses a classic downstream design 2nd stage valve (not balanced) and what Scubapro calls a balanced inflator. That is, the inflator valve is balanced, not the regulator valve.

 

[rogersab1223]

I see.

Well, I know a few guys who've dive it with a sherwood sr1 to 200ft depths with no issues.

So does it really matter?

 

[redacted]

I see.

Well, I know a few guys who've dive it with a sherwood sr1 to 200ft depths with no issues.

So does it really matter?

Only a little. A balanced valve is less effected by changes in IP so performance should be more consistent than with an unbalanced valve. Although, if you use a balanced 1st stage, then IP is more consistent anyway and the difference is less noticeable. They may not provide the breathing performance of a well tuned primary but they are perfectly able to get the job done. And , it is not at all difficult to tweak them a little (between dives) if they start to freeflow a bit or become harder breathing

 

[herman]

Doug - you've used it?

Any issues at depth (like 90+ feet) with free flow when hooked up to a high-performance primary? (Aqualung legend lx supreme)

I do not know for sure but my guess is the airlink is not balanced. As far as I know, none of the combined octo/inflator regs are. The issue with putting a non-balanced octo of any sort on a "over balanced" first stage like the Legend is those regs do not increase IP linearly as depth increases, instead of keeping the IP constant in relation to ambient pressure - 1 psi of IP increase for each 1 psi of ambient pressure increase, regs like the Legend are designed to increase the IP at about 1.1 psi per 1 psi of ambient pressure increase....what all that means is at 100 ft the IP is increased by an extra 10 psi as compared to other regs. If an unbalanced second stage is connected to an "over balanced" first stage AND it is tuned to the very edge of freeflow, the extra few psi of IP at some depth would make it start to slightly freeflow. In practice, most techs do not adjust primary second stages that close to the edge and certainly not an octo...most tune an octo slightly more conservative to prevent freeflows. At worst, the octo would start to slightly freeflow at some depth and gradually get worse as depth increased. If that happens, it's a simple thing to slightly increase the cracking pressure of the octo to compensate for the increased IP. If I were diving an overbalanced reg to depths greater than normal rec limits I would be a little concerned about it and opt for a balanced octo. That said, if I were diving to depths where that became an issue, I would not be using an octo/inflator combo. IMO, it’s not worth buying a balanced (and more expensive) octo for the sake of the minor performance increase you get...after all it’s an octo and if you are using it, it’s time to go up.

 

[NCadiver]

it’s not worth buying a balanced (and more expensive) octo for the sake of the minor performance increase you get...after all it’s an octo and if you are using it, it’s time to go up.

The guys diving with the hose wrap around themselves would disagree but that there opinion.

 

[redacted]

The guys diving with the hose wrap around themselves would disagree but that there opinion.

Some might but not all. Almost all my rigs have a balanced primary and an adjustable alternate. That gives me top performance with the regulator in my mouth and maximum control over the necklaced alternate. I don't believe any modern adjustable 2nds are made with an unbalanced design, although some can be converted. So some of these "wrap around" divers with two balanced 2nds may be just be exercising their only alternative for an adjustable alternate (and may not even realize it).