Overbalance reg = hype?

[JS1scuba]

The overbalanced design of the APEKs and AquaLung Legend series regulators allow for an increase in the intermediate pressure while progressing to deeper depths. As Oxyhacker mentioned the 2nd stages are balanced as well. This combination of ovebalanced 1st and balanced 2nd makes these breathe exceptionally well in high demand situations. Properly adjusted (factory specs) these regs perform better than most any others out there. I've been using these for about 22 mos now on some very demanding dives and they are flawless. Aqualung and Apeks have this hands down better than anyone else out there. I value my life and my life depends on these regulators.

Regards,

 

[Demi]

Technically its not hype. The Legend regulator increases the I.P. pressure at a rate greater than the average non overbalanced design. This is done because the air at depth is denser than the air at a much shallower depth. This overbalanced design breathes better at depth. The ANTSI machine proves it. However, can a human tell the subtle diffrences than the machine can, probably not. So during recreational depths no you could probably tell no difference. But I believe you can tell a difference at depths beyond 100 feet.

 

[Demi]

I agree whole heartedly with JS1scuba.

 

[NineGill]

Could someone explain why it would be good to be overbalanced vs. just balanced? If I am understanding correctly a balanced regulator increases pressure to match ambient pressure exactly; whereas an overbalanced regulator increase pressure slightly more than what is needed to match ambient pressure.

It seems that with a truly balanced design you would have identical performance shallow and deep, assuming that the regulator could provide an adequate flow at depth. Wouldn't this be ideal? Or is the "adequate flow at depth" the tricky part.

I'm not knocking Apex, because I consistently hear good reviews of their products; I just don't understand the concept of "over" balancing.

 

[jonnythan]

Could someone explain why it would be good to be overbalanced vs. just balanced? If I am understanding correctly a balanced regulator increases pressure to match ambient pressure exactly; whereas an overbalanced regulator increase pressure slightly more than what is needed to match ambient pressure.

It seems that with a truly balanced design you would have identical performance shallow and deep, assuming that the regulator could provide an adequate flow at depth. Wouldn't this be ideal? Or is the "adequate flow at depth" the tricky part.

I'm not knocking Apex, because I consistently hear good reviews of their products; I just don't understand the concept of "over" balancing.

Read post #2 in this thread.

 

[JS1scuba]

Technically its not hype. The Legend regulator increases the I.P. pressure at a rate greater than the average non overbalanced design. This is done because the air at depth is denser than the air at a much shallower depth. This overbalanced design breathes better at depth. The ANSTI machine proves it. However, can a human tell the subtle diffrences than the machine can, probably not. So during recreational depths no you could probably tell no difference. But I believe you can tell a difference at depths beyond 100 feet.

It's important to understand that the ANSTI machine comes in a few different versions. One is a "dry test" unit that only subjects the regulator to a flow and cracking pressure test in pressurized air environment. This is a popular machine and many of the smaller companies have them. They are an excellent basis to START the test and are used by many companies to ensure consistency among products being delivered.

Then there is the "wet pot" ANSTI machine. In the USA there are 3 of them. AquaLung, Kirby Morgan and I believe ScubaPro have one. In Europe they are at APEKS, Aqualung / Spirotechnique, Beuchat, Mares, and another facility that I dont recall. These machines let the technicial put the regulator in pressurized water and adjust that water temperature with a huge range. With water surrounding the 2nd stage you get a much more accurate "picture" of how the 2nd stage performs when it comes to work of breathing, cracking effort, and smoothness of the response. These machines are used not only for regulators but for rebreathers, diving helmets etc.

I've witnessed using these machines when I was testing regulators for my previous company and while a dry ANSTI machine is nice nothing beats a test off a wet machine. http://www.ansti.com/

Here is a very good article by Mike Ward from Kirby Morgan on regulator performance and testing procedures --- http://divelab.com/regulator_performance.htm

Oh and these puppies aint cheap.

Cheers

 

[redacted]

If I am understanding correctly a balanced regulator increases pressure to match ambient pressure .

All regulators are balanced for ambient pressure; that is the pressure of the environment that it is operating in. But regulators can also be "balanced" to compensate for the downstream pressure of the supplied gas. In this case, I believe they are talking about a balanced diaphram 1st stage design which allows some interesting options as the designer can easilly vary the size of the balance chamber mechanism for whatever results they desire.

 

[oxyhacker]

Usually we use the term "depth compensated" or just "compensated" to refer to a stage's ability to compensate for ambient pressure, and "balanced" or "pressure balanced" to refer to whatever features the designer may have added to keep the output pressure constant regardless of fluctuations in the input pressure.

Either one can be tinkered with to create an overbalanced (or underbalanced) effect, and sometimes are, depending on the designer's intent and the current fashion.

All regulators are balanced for ambient pressure; that is the pressure of the environment that it is operating in. But regulators can also be "balanced" to compensate for the downstream pressure of the supplied gas. In this case, I believe they are talking about a balanced diaphram 1st stage design which allows some interesting options as the designer can easilly vary the size of the balance chamber mechanism for whatever results they desire.