My Nitrox Stick build

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...it has a crankcase vent at the bottom which sometimes leaks a drop of oil
Any blow-by coming out of the vent? Must have pretty amazing ring seal if not.
 
Update:

Finally got all the misc. pieces and parts in and got it up and running today. I've adjusted the intake to take a suction from inside the basement, instead of in the garage, to get cooler, dryer air to start with. I don't like the cheap flowmeter/valve combo I got. It sort of gets the job done (and worked honestly), but it's not easy to read, it doesn't lock in a rate very well (needs adjusting every 10 minutes or so as it starts to drift) etc. so I'll be upgrading to a dwyer flowmeter and a nice needle valve. I went with camlock connections so I can easily disconnect everything and put the compressor and suction hose away when not in use since the area I'm running it in is not suitable as a long-term storage area (too much traffic walking through... my garage is too full :( ).

Overall, everything worked well. I was shooting for 32% mix topping off tanks with ~25% in them to start with, and using the continuous blend mixes calculated at Gas blender toolkit to achieve that 32% in the end. As mentioned earlier, I did have drift on the meter that I had to routinely adjust for so I was happy if I had it plus or minus ~0.4% at the time. I ended up getting 32.3% in both tanks in the end. I'm sure I can dial that in a bit with a better flowmeter and a more stable valve later, but it's working "good enough" already, so I'm happy with everything as it is so far.

Gotta seal up around the PVC pipe going into the basement yet though.... here's some pics while it was running

nitrox stick installed.jpg

compressor with extension.jpg
 
Update:

Finally got all the misc. pieces and parts in and got it up and running today. I've adjusted the intake to take a suction from inside the basement, instead of in the garage, to get cooler, dryer air to start with. I don't like the cheap flowmeter/valve combo I got. It sort of gets the job done (and worked honestly), but it's not easy to read, it doesn't lock in a rate very well (needs adjusting every 10 minutes or so as it starts to drift) etc. so I'll be upgrading to a dwyer flowmeter and a nice needle valve. I went with camlock connections so I can easily disconnect everything and put the compressor and suction hose away when not in use since the area I'm running it in is not suitable as a long-term storage area (too much traffic walking through... my garage is too full :( ).

Overall, everything worked well. I was shooting for 32% mix topping off tanks with ~25% in them to start with, and using the continuous blend mixes calculated at Gas blender toolkit to achieve that 32% in the end. As mentioned earlier, I did have drift on the meter that I had to routinely adjust for so I was happy if I had it plus or minus ~0.4% at the time. I ended up getting 32.3% in both tanks in the end. I'm sure I can dial that in a bit with a better flowmeter and a more stable valve later, but it's working "good enough" already, so I'm happy with everything as it is so far.

Gotta seal up around the PVC pipe going into the basement yet though.... here's some pics while it was running

View attachment 675448

View attachment 675449
How steady is your output pressure to the flowmeter. I found that regulated pressure rose as tank pressure dropped. This changed both the indicated flow rate and the actual flow rate by more. I ended up feeding one pressure regulator into another one which locked the pressure for the whole tank of O2.
 
How steady is your output pressure to the flowmeter. I found that regulated pressure rose as tank pressure dropped. This changed both the indicated flow rate and the actual flow rate by more. I ended up feeding one pressure regulator into another one which locked the pressure for the whole tank of O2.
The supply pressure was pretty well constant at 50psi to the flowmeter with no noticeable variation on the pressure gauge of the regulator (bottle pressure finished around 850psi today). The flowmeter was very "squirrely" for lack of a better term. It would sometimes give me more, sometimes less, sometimes a tiny movement on the integrated valve would result in the flow indicator moving up or down slowly, sometimes it was jerky, and overall just had no indication to me that it was doing a great job at it's ... job. I'm putting in a parker needle valve to adjust flow with (I'll just open up the flowmeter's valve and control with the Parker), then I'll see if the flowmeter is reliable or if I need to swap it out too. I'm guessing the latter, but if not I'll be happy to save a couple bucks and keep what I've already bought I guess.
 

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