You'll expend very little gas by simply hooking up the regulator, with your attached IP gauge. Just leave it for a minute or two and see whether you witness that IP creep again. Push the purge -- gently -- on the second a couple of times; see how quickly the IP rebounds and or stabilizes; check out that field repair document, if needed, from the previous post . . .
Thanks for the suggestions. I tried this with a full tank (@3200-3300 psi) and the behavior was different. The first couple of times I took a breath or purged, the pressure came down to about 100 psi and then instantly rebounded to 120 then increased to 130 within a few seconds, and then after the first few cycles it rebounded to 120 then increased progressively (a few seconds) to 125 psi, where it stayed stable for several minutes. So I was less worried at that point.
However, following my dives yesterday morning (with another reg) I decided to retest with the lower pressure tank, and observed a similar slow creep as initially. Pressure would rebound to 130 or so after a purge and then increase slowly past 150 (maybe 20 sec time) and then would climb to ~195 psi over several minutes, after which it would stabilize.
I decided to do several cycles of breathing/purging to see if things would change, and now it seems I've caused complete failure of the high pressure seat. After less than 10 cycles of purging/rebounding, I heard a hissing sound and had to quickly shut the tank valve. It seems the OPV kicked in and now every time I attempt to pressurize the reg, the intermediate pressure gauge rises straight to >200 psi, followed by pressure release from the OPV on the bottom of the first stage.
I am a bit baffled as to how purging the second a few times like this (although admittedly a bit violent) could cause such drastic failure in a non-defective product to begin with. Actually, I am a bit relieved that I did this testing in my garage and this seat failure did not happen on a dive (again, this reg has supposedly never seen water). Not sure what to do at this point.
This particular ruby ball/HP seat design doesn't need "seating in" cycles like traditional sharp edge orifices on their seat.
Therefore, I'd conclude that it needs either
a) brisk high-flow purging to blow out a speck of grit or a fiber that's stuck between the ball and seat, or
b) a new seat.
Hook the reg to a tank with an OPEN low pressure port (no hose), and cycle the tank valve on/off several times. Then retest your IP. Make sure to hold on to the tank when you cycle it, and point the port away from you.
It's unlikely the ruby ball is scratched in a new product, so a seat flaw is more likely. Maybe that's why it got offered for sale.
Send it to me if you can't find local service.
Thanks very much for your input (obviously at this point I can't try your suggestions unfortunately...) and offer to send you the reg for servicing. Indeed, local service for Poseidon regs is not available here, but I had made the decision to purchase anyway and send the reg away when the need for service would arise. However, since the reg is brand new, I would assume that this is something that should be covered by the Poseidon warranty? Regarding the dealer that sold it to me, it was a good price, but not a special sale, as they are still advertising it at the same price, although now not in stock any longer and would have to be ordered directly from Poseidon. So although I don't know what they may or may not have done to this specific first stage while they had it in stock, I don't think they specifically lowered to price to get rid of that one.
