Yes, maybe closing the valve and taking sniffs is another good method (less wear on the switch), I’ll try that.
For the checklist lovers, the manual (2019-08-02), page 12 states (my bold):
OXYGEN SYSTEM POST-FLIGHT
1. Turn off the EDS unit.
2. Close the oxygen cylinder valve (leaving the regulator pressurized when not in use can shorten service life).
3. Bleed the regulator and EDS inlet line (see BLEEDING THE REGULATOR, page 8).
4. Stow cannulas/facemasks/tubing to prevent contamination (see STORING THE EDS, page 20).
and page 8 (my bold):
BLEEDING THE REGULATOR
Bleed the regulator between uses. Leaving the regulator pressurized when not in use will shorten its service life.
1. Make sure the oxygen cylinder valve is closed.
2. Remove the regulator outlet tubing from the EDS inlet fitting. Merely removing the tubing from the regulator outlet
fitting of an XCP or FPR type regulator will not actually bleed the regulator as the check-valves incorporated into the CPC outlet fittings will retain pressure in the regulator (also applies to the 6mm Split-Kit, see CONNECTING TO YOUR REGULATOR, p. 16). You may hear the gas escaping as you do this.
I have never done this.
The regulator valve is normally shut, and indeed shuts when the batteries go flat, too. But it leaks a little bit and after some hours the pressure will be gone. The 1st stage reg delivers about 20psi so when you shut off the main cylinder valve, the pressure will be gone soon.
Otherwise, you can bleed the pressure just by closing the cylinder valve, taking a few sniffs, until the pressure is gone, then switching off the O2D2.
I would definitely not pull the tube out; those fittings are not designed for a frequent disconnect. Well, those going into the 1st stage reg would be ok to pop out, but why? It just knackers the seals.
Thanks Emir, yes it works pretty good this way, and is easier to do than fiddling with the Festo fitting and release ring…
Still, in the manual it say to disconnect the line after use to release the pressure, so maybe this ON/OFF method ain’t the best?
Dan wrote:
Since it is more convenient than removing the tubing, I was wondering if there is any wrongdoing by using this method… any takers?
On and off with closed supply works because test will bleed the pressure.
Question to the audience, how do you bleed your O2 system?
Installed a O2D2-2G system in my ship a few months ago, and pretty happy with the install and operation of the unit (but for the initial tickling of my nostril hair 
)
Page 8 of the manual states: BLEEDING THE REGULATOR, Remove the regulator outlet tubing from the EDS inlet fitting. It also recommends bleeding the pressure after each use.
Having read another manual for the older version of the unit, it said to switch it ON/OFF for a few times (yes, bottle closed…) until all the pressure is out.
Since it is more convenient than removing the tubing, I was wondering if there is any wrongdoing by using this method… any takers? Alternate method?
@dan post moved here.
I did it this year, just in case. They overhauled the unit and upgraded the firmware. I don’t plan on doing this every 3 years though…
Never had any complaints and no complaints after the overhaul neither.
It’s been alleged that these products have to be sent to MH for some sort of service every 3 years.
Has anyone heard of this?
Mine have worked perfectly for something like 10 years.
I run two O2D2 units in parallel. The units work OK, although I sometimes get unexplainable alerts.
If that happens I move the beeping unit to some other place, and then it usually stops.
I don’t know what causes it. It could be some cabin airflow that affect the pressure sensing system.
When flying with 3 or 4 on board, I also bring 2 constant flow cannulas as a backup.
