Air 2 free flow while scootering

[PfcAJ]

Balanced vs unbalanced is not a variable in the sensetivity of a 2nd stage (propensity to freeflow). It is much more regulated by case, cover, diaphragm, lever, and poppet design; and proper adjustment and tuning. For 2nds t6hat do not have a seat saver feature, wear (setting) of the seat occurs almost entirely when the reg is not in use. When the reg is under pressure force of the seat against the orifice is just enough to stop the flow of gas. That force is the same whether it is provided entirely by a mechanical spring or by a combintion od mechanical and pneumatic spring. An adjustable 2nd, like a 109 or 156, allowa an alternate 2nd to be detuned a bit during the dive to resist the effects of current, surge, or scootering.

Does not jive with my experience. Folks routinely tune balanced adjustables to be super sensitive (that's the point) and then crank down that knob so it's less sensitive and leave it like that. There's more force on the seat over time than a normally tuned (not super duper on the edge of free flow) unbalanced reg.

 

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Does not jive with my experience. Folks routinely tune balanced adjustables to be super sensitive (that's the point) and then crank down that knob so it's less sensitive and leave it like that. There's more force on the seat over time than a normally tuned (not super duper on the edge of free flow) unbalanced reg.

Do you have any experience with unbalanced adjustables? I tune my balanced adjustables and my adjustables the same way; both super sensative. Then I detune the alternate an extra turn until I want to use it. I store thoes regs with the purge depressed to qavoid unnecessary engraving.

 

[PfcAJ]

Do you have any experience with unbalanced adjustables? I tune my balanced adjustables and my adjustables the same way; both super sensative. Then I detune the alternate an extra turn until I want to use it. I store thoes regs with the purge depressed to qavoid unnecessary engraving.

Unbalanced adjustable? Nah. Most of my fleet is g250 type or r190 type.

 

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Unbalanced adjustable? Nah. Most of my fleet is g250 type or r190 type.

that may be the problem. you are trying to compare a balanced adjustable barrel poppet 2nd with a classic downstream 2nd. Those two designs differ on many more characteristics than balanced vs unbalanced.

i usually use classic downstream 2nds only on bailout bottles. my main rigs all have a balanced primary and an adjustable alternate.

 

[PfcAJ]

that may be the problem. you are trying to compare a balanced adjustable barrel poppet 2nd with a classic downstream 2nd. Those two designs differ on many more characteristics than balanced vs unbalanced.

i usually use classic downstream 2nds only on bailout bottles. my main rigs all have a balanced primary and an adjustable alternate.

Always down to try new stuff. Point me towards an unbalanced adjustable with a faceplate that's removable without tools.

 

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Always down to try new stuff. Point me towards an unbalanced adjustable with a faceplate that's removable without tools.

a 109 is the only unbalanced adjustable ever made and does not have an easily removed face plate. if you really wanted an unbalanced adjustable wityh an easily removed face plate, it would be quite easy to convert a G250 (original design). But, if you are looking for an adjustable alternate, a G250 will do the job quite well and might even breath just a tiny bit better than its unbalanced version.

years ago I hoarded the 109 parts so I could convert my balanced adjustables back to unbalanced if I could not find the balanced poppet seat. I had developed the ability to make my own unbalanced seats as alternate sources for the rivet style balanced seats had not yet opened up.

 

[PfcAJ]

a 109 is the only unbalanced adjustable ever made and does not have an easily removed face plate. if you really wanted an unbalanced adjustable wityh an easily removed face plate, it would be quite easy to convert a G250 (original design). But, if you are looking for an adjustable alternate, a G250 will do the job quite well and might even breath just a tiny bit better than its unbalanced version.

years ago I hoarded the 109 parts so I could convert my balanced adjustables back to unbalanced if I could not find the balanced poppet seat. I had developed the ability to make my own unbalanced seats as alternate sources for the rivet style balanced seats had not yet opened up.

I think we've come full circle and back to a g250 tuned to be on the verge of leaking then having to turn the adjustment knob to get it to not dribble when scootering. That's exactly what I don't want

 

[andrewy]

a 109 is the only unbalanced adjustable ever made and does not have an easily removed face plate. if you really wanted an unbalanced adjustable wityh an easily removed face plate, it would be quite easy to convert a G250 (original design). But, if you are looking for an adjustable alternate, a G250 will do the job quite well and might even breath just a tiny bit better than its unbalanced version.

years ago I hoarded the 109 parts so I could convert my balanced adjustables back to unbalanced if I could not find the balanced poppet seat. I had developed the a bility to make my own unbalanced seats as alternate sources for the rivet style balanced seats had not yet opened up.

You guys dragged me into.. like i said before.. there 2 more unbalanced, adjustable scubapro stages, based on 109 design. Specifically Polar (for European markets) and M50 for US market. they are hard to come by. yet, it has same body ar g250 and you can take it apart without tools (provided you remove the pin). the regs have same design as 109 yet all made from plastic internally to prevent freezing.
IMHO these are the best for backups if u find them on ebay. It has simple on/off switch and i dont see any difference to my G250 at moderate < 150ft depth.

 

[redacted]

I think we've come full circle and back to a g250 tuned to be on the verge of leaking then having to turn the adjustment knob to get it to not dribble when scootering. That's exactly what I don't want

So you chose a noticably lower performance detuned R190???

I suppose you could develop a way to protect a well tuned high performance regulator so it is not exposed to the forces that initiate a freeflow. but it just seems easier to me to simply provide the user a control that allows the dynamic adjustment of cracking pressure to adjust fort such situations.

 

[redacted]

You guys dragged me into.. like i said before.. there 2 more unbalanced, adjustable scubapro stages, based on 109 design. Specifically Polar (for European markets) and M50 for US market. they are hard to come by. yet, it has same body ar g250 and you can take it apart without tools (provided you remove the pin). the regs have same design as 109 yet all made from plastic internally to prevent freezing.
IMHO these are the best for backups if u find them on ebay. It has simple on/off switch and i dont see any difference to my G250 at moderate < 150ft depth.

I keep forgetting about those. I don't think I have ever seen one other than in schematics.

I relooked at their schematics. Looks like it would be simple to convert them to balanced if the urge ever hit.