Scubapro chrome plated brass regulators...

[Angelo Farina]

I just add that the Venturi effect on the 109/156 start to be present only at significant depth, say below 50m. The higher density of air gives some Venturi effect, whilst at smaller depth this effect is not present.
In fact, when I purchased my first MKV (that is a MK5+109, factory tuned) and tested it in the swimming pool, I complained with the shop that it was not much smoother than other regs I tested.
The seller told me: "try it at 50m, and then report back". The next sunday I dove it at 50m, and it was way smoother than my previous reg (an old Aquilon) thay I kept as second. The 109 works better at depth than at surface...

 

[Open Ocean Diver]

Wow that’s really interesting I guess that explains my readings. So I assumed then with the Viva turned to pre-dive disturbing the air to help prevent free flow it also helps directs the air in dive-mode to creates more of a Venturi assist... is that correct? I thought it was only there to cancel some of the Venturi effect to prevent free flow and in dive-mode it basically wasn’t doing anything and the Venturi effect was all case and air barrel design.

 

[Open Ocean Diver]

Sorry, can't confirm that.
If I test my 109/BAs on my Flow Bench, I get sometimes similar results as Overweighted with no Venturi whatsoever.
If the Venturi kicks in at all, it happens usually pretty late (at 7,5 SCFM or later) and not so 'violently', no comparison with the 'newer' models with Flow Vanes where the Crossover Flow Rate Point is sometimes below 5 SCFM and with full Free FlowView attachment 579701 .....

That’s quite the stash of hardware you have there, now I know where they’re all at. Lol

 

[Umuntu]

Impressive collection !

Why so many 109 bodies ?

 

[axxel57]

Impressive collection !

Why so many 109 bodies ?

Some are in not so good condition, so it seems, I dismantled them for parts, I have them already for so long time that I don't remember exact.

I really don't know why I'm still collecting them, I even don't dive them (just once I dived one of my BAs)......

I just like them, and just last weekend I found my first Mark X 2nd and couldn't resist......

And communicating with Angelo I checked my stuff and found my 129 I had 'lost' for years.

I will check now how many combos more I have (there should be a couple), maybe that helps to reduce my addiction....

I know it's not normal, but I have the feeling I'm not completely alone here with that......

 

[Open Ocean Diver]

I don’t see one Scubapro BA 156 Mark X dual balanced.. in satin. Your collecting days are not over. Lol

 

[Umuntu]

Those are a lovely collection. I see the 129 on the left.

I have been looking for a 129 or just it's body for a while, but they don't ever seem to come up.

I do dive my 156s and 109BA's. They don't breathe as good as the Apeks 2nds, but are still beautiful breathers.

Now I'm tempted to experiment with some thin brass sheet to install a venturi vane. Though it won't affect initial cracking effort and I don't have the equipment to do flow tests

 

[Open Ocean Diver]

I could do the testing, what do you think about using cardboard trimmed as a test vane?

 

[Umuntu]

I could do the testing, what do you think about using cardboard trimmed as a test vane?

I personally don't think cardboard would be rigid enough to cope with the airflow. I would think you would need a stronger, more rigid material. An Apeks style vane is bent.

See some pictures of the Apeks vane.

 

[Open Ocean Diver]

How about copper sheet trimmed to a friction fit.