Scubapro chrome plated brass regulators...

[Open Ocean Diver]

I do the same thing. Great way to save on air for dynamic flow measurements, compared with the Venturi vacuum generator in the Regulator Savvy/ScubaTools model. Just hook a small vac (I use a cheap tiny model Home Depot shop vac) to the top of the rotameter, and you've easily got 20SCFM flow to test with. A little noisy, but in my experience, no less noisy than that Venturi vacuum, which blows through an AL80 in a couple of minutes. You can see the old 1/4" copper line which used to feed the Venturi, disconnected at the top of the rotameter.
View attachment 580169
View attachment 580170
The vacuum is on a dimmer switch, which makes it easy to change suck, and I added an air bleed (the orange valve) at the top for fine tuning of suction, especially at low flows. With the vacuum tucked out of sight under the table, and inside a box, noise is pretty minimal.

This is the reg you sold me cross over flow.

 

[Umuntu]

Coming back on topic to the old brass-chrome models, the way of understanding where they were manufactured is in the two small screws closing the ring around the reg. In Italian-made samples these two small screws are metric (M3x0.5, for being precise).
In the US-made samples these screws are in Imperial units, a bit larger, they do not screw in Italian regs.

@Angelo Farina,

Thank you for confirming the metric thread size of the 108/109/156 clamp screws as M3 x 0.5. Now where to source them in UK/Europe in brass with a small head size !?

The imperial screws in "4-40" thread , brass and with reduced head size are available from vintage double hose's website.

 

[Umuntu]

Also, there are two types of 108/109/156 cover clamps:

One type of cover clamp has both of the threaded screw holes in the bottom half and both the unthreaded holes on the top half.

The other type of cover clamp has two identical halves, with one screw hole threaded and the other screw hole unthreaded.

Does anyone here know if this is an Italian vs USA manufacturer difference or an earlier vs later difference?

I can see that the second type would have simplified manufacturing and reduced costs.

 

[James79]

Also, there are two types of 108/109/156 cover clamps:

One type of cover clamp has both of the threaded screw holes in the bottom half and both the unthreaded holes on the top half.

The other type of cover clamp has two identical halves, with one screw hole threaded and the other screw hole unthreaded.

Does anyone here know if this is an Italian vs USA manufacturer difference or an earlier vs later difference?

I can see that the second type would have simplified manufacturing and reduced costs.

I don't have the reference, but I seem to recall it being a production date thing, rather than location.
Respectfully
James

 

[Umuntu]

If only there was a way to "bypass" these issues and find a metal second that could passively reduce inhalation resistance without increasing tendency to freeflow.

It could look like this:
View attachment 580241


[ducks]

I wish Greg Barlow was still contributing here. We could then have an American representing the Italian Mares versus Angelo Farina representing the American SP.

Almost all the Mares regulator 2nds use the same unbalanced downstream demand with a bypass venturi tube design. I think there are old versions in chromed brass. I understand that design works very well in co!d water diving. They come up occasionally second hand.

I have serviced, but never dived, Mares.

 

[Open Ocean Diver]

Also, there are two types of 108/109/156 cover clamps:

One type of cover clamp has both of the threaded screw holes in the bottom half and both the unthreaded holes on the top half.

The other type of cover clamp has two identical halves, with one screw hole threaded and the other screw hole unthreaded.

Does anyone here know if this is an Italian vs USA manufacturer difference or an earlier vs later difference?

I can see that the second type would have simplified manufacturing and reduced costs.

Mine have hex screws instead of Phillips is that anyway of telling where produced?

 

[Couv]

Sorry to stir up trouble with my little dimmer. If it helps, it's a very cheap vacuum cleaner.
And I've never seen any smoke

Not a problem Mr. Troublemaker. If it works, it works. That's why I deleted post #117 until I was bullied into re-posting it.

 

[lexvil]

Not a problem Mr. Troublemaker. If it works, it works. That's why I deleted post #117 until I was bullied into re-posting it.

Don’t worry, I initially thought the same, experience being with large 3 phase we had cycle controllers (HTZ) to regulate speed, never gave any thought to variable speed on small stuff until it was pointed out here. I would just use the ball valve to regulate flow and pipe the vac outside.

 

[Couv]

If only there was a way to "bypass" these issues and find a metal second that could passively reduce inhalation resistance without increasing tendency to freeflow.

It could look like this:
View attachment 580241

[ducks]

I wish Greg Barlow was still contributing here. We could then have an American representing the Italian Mares versus Angelo Farina representing the American SP.

The second stage above looks much like the very first regulator I ever dove. It belonged to my roommate in the early 1970ies. Yes, this one is fancied up a bit, but it's still an AMF Voit Swimaster.

Venturi & Bernoulli are up there somewhere smiling.

 

[Open Ocean Diver]

Not a problem Mr. Troublemaker. If it works, it works. That's why I deleted post #117 until I was bullied into re-posting it.

It was a nice tangent.