Pneumatically balanced second stage

[milosusa]

Hi to everybody again, I do have another Q. about regulators. It is any big advantage of the pneumatically balanced second stage compare to mechanical balancing system I do have on my Oceanic GT3 with adjustable inhalation system. It is much easiest to breath thru pneumatically balanced second ? Somehow I am curious about how different diving stuff work in real live.
THX milos

 

[Luis H]

The initial cracking suction should be the same whether it is pneumatically balanced or not.

The pneumatically balanced is affected substantially less by IP (intermediate pressure) changes; therefore any momentary IP drop during the inhalation cycle (see note) will not increase the required suction to sustain the flow. All good second stages use a venturi effect to assist in maintaining this flow, but the venturi performance is less critical if the second stage is pneumatically balanced.

Note: If you place an IP gauge on your regulator, you will notice a slight momentary IP drop during the inhalation cycle.

The mechanical coil spring in a pneumatically balanced second stage is lighter, which should reduce the indentation on second stage seat during storage.

IMHO the pneumatically balanced mechanism is a relatively simple improvement with very little draw backs relative to its improvement. It does add a couple more O-rings, but IMHO it can improve consistent performance between relatively longer service intervals.

It is a small improvement, but there haven’t been any large improvements in the last 30 years.

I converted all my Scubapro 109 to balance adjustable and they work great with very little maintenance