Balanced or Overbalanced and Cold Water conversions

[Remy B.]

For the AQUA-LUNG manufacturer

I converted two of my Titan regulators, from tropical water to cold water, the regulator performed better after the conversion, much easier breathing, I was explained that because of that second membrane that now seals the spring chamber aids in the balancing thru a tine rod as with that membrane there is more area of contact to help push the Diaphragm, and because of this it becomes overbalanced.

I kind of understand the explanation, but is it like that or what is the explanation for that better breathing ?, or to put it in another context what what are the difference between the so called balanced and over-balanced. 1st stages

 

[guruboy]

It's probably the higher IP which lowers the effort needed to breath since there is more pressure pushing against the LP seat.

You could probably have gotten the same result by tuning the 2nd stage more.

 

[runsongas]

For the AQUA-LUNG manufacturer

I converted two of my Titan regulators, from tropical water to cold water, the regulator performed better after the conversion, much easier breathing, I was explained that because of that second membrane that now seals the spring chamber aids in the balancing thru a tine rod as with that membrane there is more area of contact to help push the Diaphragm, and because of this it becomes overbalanced.

I kind of understand the explanation, but is it like that or what is the explanation for that better breathing ?, or to put it in another context what what are the difference between the so called balanced and over-balanced. 1st stages

do you have numbers on the cracking pressure and IP setting before and after the conversion? are you comparing performance deeper than 100ft? sounds like it just got adjusted better. the same 2nd stage hooked up to a UST vs a DST at the same IP will perform the same until you start getting deeper where the DST will increase the IP.

 

[herman]

For the AQUA-LUNG manufacturer

I converted two of my Titan regulators, from tropical water to cold water, the regulator performed better after the conversion, much easier breathing, I was explained that because of that second membrane that now seals the spring chamber aids in the balancing thru a tine rod as with that membrane there is more area of contact to help push the Diaphragm, and because of this it becomes overbalanced.

I kind of understand the explanation, but is it like that or what is the explanation for that better breathing ?, or to put it in another context what what are the difference between the so called balanced and over-balanced. 1st stages

Pure horse poo by someone who has no idea how a reg works..
The only thing that the cold water kit does is isolate the main spring from the water..plus a little more explained below.
First stage balancing is TOTALLY the work of the balance chamber which is located inside the reg and is never exposed to the water. The environmental seal has no effect on it.
The term "overbalanced' is technically incorrect, it is actually "over depth compensated". In a nut shell, IP is maintained constant through out the range of tank pressure by the balancing chamber, that is first state balancing. At the same time, the IP as referenced to ambient pressure is kept constant relative to ambient pressure by the main spring, main diaphragm and in a sealed unit the, environmental seal. As depth increases ( and ambient pressure) the IP tracks keeping it at the same differential. In other words, at the surface your IP is at say 135 psi and ambient is at zero (yea I know its 14.7 but it does not matter for this discussion) . At 100 ft ambient pressure has risen to about 59 psi so your IP will be 135 + 59= 194 but is still just 135 psi above ambient (59 psi) . That is without the environmental kit. With it, do to it's slightly larger diameter your IP will track with ambient plus about 10%. At the surface it will still be 135 but at 100 ft it will be 135 + 59 + 5.9=199.9.
With all that said, as long as IP stays within a reasonable range, none of it has ANY bearing on how your second stage breaths because it is also balanced (or should be with an "overbalanced" first stage). The purpose of balancing a second stage is to keep WOB constant over varing IPs. Balancing a second stage has the effect of nullifying IP changes so the extra 6 psi from the overbalance has no effect and because it is at the same ambient pressure as the first stage, the increased IP ( but again it is still at the same differential from ambient) has no effect on the performance of the second stage. Even if you are using unbalanced second stages, the effect of overbalancing will not be noticed until a significant depth, if then.
Bottom line of all this is unless your IP was WAY off to start with, adding an environmental kit will have no effect with how a balanced second stage performs (and very little with an unbalanced ). If there was a noticeable change , something was done to the second stage.

 

[eelnoraa]

To me, I don't see how this can help WOB in real world usage. If too little over balancing, it won't make any difference with a balanced 2nd stage. If some substantial amount, then in order to prevent free flow at depth, IP at surface must be turn very conservatively, and therefore low breathing performance at shallow depth.

I own a set of AL legend. While I like it a lot, I don't think it is any better or worse than a non over balanced (or not over depth compensate) Mk25 up to 100ft. They both have IP set to about 130psi. This lead me to believe the over balance change very little up to 100ft.

The whole over balance "feature" is marketing slogan to lure new diver into spending more money

 

[tbone1004]

what @herman said. At deep enough depths, the over depth compensation will cause them to freeflow, but that is at trimix depths, not recreational depths. It is highly unlikely you or a machine could tell the difference, especially with a balanced second stage. It's possible, but only if your second stage was tuned very badly.

@eelnoraa is mostly correct on the last sentence. It's not as much to get them to spend more money, it's to turn what is essentially a design flaw into a marketing ploy to make it sound better. They can't actually engineer that "feature" out of their regulators so they figured they'd put a positive sounding spin on it so people wouldn't shy away from it...

 

[Remy B.]

Why then is there a noticeable difference, between before and after the Dry Kit installation, why does it breathe better ?, I have two Titans both breathe better, even that the 2nd stage is a normal one without the knob to adjust the breathing effort.

 

[Remy B.]

Pure horse poo by someone who has no idea how a reg works..
At the same time, the IP as referenced to ambient pressure is kept constant relative to ambient pressure by the main spring, main diaphragm and in a sealed unit the, environmental seal. As depth increases ( and ambient pressure) the IP tracks keeping it at the same differential. In other words, at the surface your IP is at say 135 psi and ambient is at zero (yea I know its 14.7 but it does not matter for this discussion) . At 100 ft ambient pressure has risen to about 59 psi so your IP will be 135 + 59= 194 but is still just 135 psi above ambient (59 psi) . That is without the environmental kit. With it, do to it's slightly larger diameter your IP will track with ambient plus about 10%. At the surface it will still be 135 but at 100 ft it will be 135 + 59 + 5.9=199.9.

Bottom line of all this is unless your IP was WAY off to start with, adding an environmental kit will have no effect with how a balanced second stage performs (and very little with an unbalanced ). If there was a noticeable change , something was done to the second stage regulator.

My question is, what has changed, the way I see it and was explained, now you spring plate is no longer in contact with water, now it has a disc and membrane/Diaphragm on top of the spring, is this not helping it ??

Absolutely nothing was done to the second stages, it is possible that the regulators were way off from factory, I agree that this can't be ignored and is a possibility

If I read you explanation, it is kind of what I'm saying, With it, do to it's slightly larger diameter your IP will track with ambient plus about 10%., I translate this to more area of contact, that is what I'm pointing out.

 

[eelnoraa]

After the cold water kit upgrade, does our reg breath better at surface? If so, it is the proper IP tuning.

If you follow tbone's logic, if over balance change IP enough to make a different in recreation depth, at tech depth, all apeks should free flow.

 

[Remy B.]

Do you mean t

what @herman said. At deep enough depths, the over depth compensation will cause them to freeflow, but that is at trimix depths, not recreational depths. It is highly unlikely you or a machine could tell the difference, especially with a balanced second stage. It's possible, but only if your second stage was tuned very badly.

...

Can you please extend more your comment, of the APEKS free-flows, I was under the impression that they are reliable regulators for technical diving, what depths do you call trimix depths as this is a wide range.