Adjusting a mechanically balanced 2nd stage

[AquaNSun]

I have a mechanically balanced 2nd stage, Oceanic delta II, and trying to learn a good way to adjust its cracking pressure. Is the orifice adjustment still important since I have the diver's adjustable knob to play with? Do you adjust the orifice so that it free flows a bit and then fine tune with the knob? Any info is appreciated!
Thanks.

 

[Bubbletrubble]

I wrote up a fairly concise explanation of how to tune a balanced adjustable second stage in this post located in the Edge/HOG manufacturer's forum. You'll want to be sure to push in the purge button as you adjust the orifice to avoid cutting the LP seat with the knife edge.

The very first step in tuning a second stage is to make sure that the first stage is delivering the desired IP. Specs for this should be listed in the manufacturer's reg tech manual. A very common recommended IP is 140 ± 5 psi. You'll need an IP gauge to check this. You really shouldn't be tuning a second stage until the IP is verified. You're setting yourself up for failure if you skip this step. The first stage might require an overhaul/repair/tuning first.

I highly recommend that you download the reg tech manual for the Oceanic Delta II and study the tuning section in its entirety before attempting to tune it yourself. Reg tech manuals can be found on this site.

Good luck.