New Nitrox Stick

[jbscuba]

Hello everyone,
I have the Oxy Hacker's 4th edition. I am ready to build a Nitrox Stick. My question is how long do I make the 2" PVC pipe?
I am using a 4CFM compressor. I realize the book indicated 24" long, but I was advised to use a longer pipe up to 48" to give it enough mixing area.
Any ideas? Thanks!

 

[dannobee]

PM sent. If you use my design the mixing occurs within 6" and doesn't need any baffles/wiffle balls. Will you use it for nitrox exclusively, or will you be continuous blending with He, too?

 

[jbscuba]

Thanks Dan,
For my dives I have been using nitrox for 80% of them, air 10% and He dives 10%. The number of deeper dives and the boats that go to them are limited.
That was also based on getting fills at stations. If I had my own system, I could do whatever I want. If I built the stick for both, but used it mostly for nitrox, would the sensor readings be effected that much?

If that made a big difference, I could just as easily use it exclusively for nitrox. When I would require He, I could fill He directly to the tanks and calculate the O2 for the dive profile.

 

[katdiver]

I built the stick at 30" length with one extra baffle. I blend nitrox through a 8.8CFM compressor, no problems. Essentially the same as the book.

dannobee, your mini version sounds interesting.

 

[gxsr_sarge]

I pretty much followed the format in the book and have been using it for the past few months or so to blend 32%. It's a HUGE success. I can't believe I was PP blending to begin with. Now I'm sort of tweaking my input/output readings. I have to set my input at 33% to get a true 31.5% blend. I took care of all leaks. I think most of the differential lies in the fact that I'm in S. FL. where the relative humidity is 70+%. The input sensor reads at ambient air (with humidity) and the "output" readings is already dry post compressor air. But I think this only accounts for about 1/2% or so of the O2 disparity. No big deal though... I'm happy.

The only trouble I had initially was getting the remote sensor far enough into the tube so that it would give a good input reading. You may have to play around with the PVC fittings or file it to get a nice snug fit. If it's too far removed, you'll get a false O2 reading.

 

[Buzoferoz]

Few monts ago I was at the same problem¡ I read al the way the oxihaker and finish as they say (same instructions as the book) my compressor is a mk 14, 9.5 cu per min. and is working ok on that mixer, the only prob that I have is the regulator wich is working on a 77 orifice. I believe I have to modificate that, cause only can fill up to 32%

 

[Buzoferoz]

great¡ do you have any directions on how to asemble your mixer? btw join us to next isla isabel trip on mexico¡ next 15 - 19 sept¡

 

[Killer&Griller]

Although I did my sensor inline, this would work w/ a 2" tee also. If memory serves correctly, I thing the side tee reducer was a 3/4" hole that i shaved a touch. If necessary, I can check and measure it.

I took off the rubber o-ring on the sensor itself. This gave me an existing "groove" to put my spring washer (that horseshoe clip). I put a small bend in the clip as to help follow the contour of the PVC.

Before I screw on my sensor, I placed an additional o-ring on the outside of the T so that there was no leak in between the sensor and the tee itself.

Below is the pic of the sensor I used along w/ the couple of pics for modifying the sensor mounted into a PVC tee. Hope it helps......

FWIW, if you want to put together a group buy, I can purchase the analyzers from Nuvair at a discount. It can be either Pro 02 analyzer or the quick stick. If I had to guess, delivered ConUS w/ freight and PayPal charge about $205 ish - $210 depending on where I am shipping too.

O2 Analyzes, He Analyzers, CO Analyzers, CO2 Analyzers and Sensors

 

[mikeb663]

24 inches is plenty long enough for that size of compressor. I built one for the same size compressor and used two of the baffles from the oxyhacker design. One at the top where the oxygen is introduced and one at the bottom. The rest of the space is filled with Bio Balls which are basically the same as using practice golf balls, but they keep the turbulence up so that everything mixes. I hope this helps

 

[Apecks]

Looking into building one in the next few months. Has anybody got pics of there completed system and or a material list.