Mixing stick

[oxyhacker]

There's a picture, not very big unfortunately, in the GALLERY on our website, at the link below. Most sensors will screw into a 3/8" NPT hole even though they aren't really threaded NPT, however it is much easier to use the little O-ring sealed "flow diverter" that comes with the teledyne ones, and fits into a 9/16" hole. The Oxy Hacker stick has a PVC tee at the bottom, and the sensor goes into one of the ports which has been bushed and drilled out to take the flow diverter, but there's a barbed plastic tee you'll find in most hardware stores that will perfectly fit the diverter without any modification.

Not rocket science - take you sensor and adaptor to the hardware store and you'l find many fits.

Can someone post a picture of the setup that you have for the sensor at the bottom of the stick (prior to compression/detonation)? Thanks

 

[pensacola]

Thanks for the info- I was just perpetuating the bad joke about the "detonation" thing (ie, if the regulator started free-flowing O2 into the stick and blew up the compressor).

 

[rcontrera]

Thanks for the info- I was just perpetuating the bad joke about the "detonation" thing (ie, if the regulator started free-flowing O2 into the stick and blew up the compressor).

Not such a bad joke after all! Recently a compressor in my area decided to toss a chunk out of the final stage and ignite in protest of too much oxygen being pumped through it at too high a pressure.

REMEMBER ... 40%/3000 PSI max is al the compressor manufacturers say can run through these beasts. Any higher and you may cause premature oil degradation and/or compressor damage

 

[omar]

Not such a bad joke after all! Recently a compressor in my area decided to toss a chunk out of the final stage and ignite in protest of too much oxygen being pumped through it at too high a pressure.

REMEMBER ... 40%/3000 PSI max is al the compressor manufacturers say can run through these beasts. Any higher and you may cause premature oil degradation and/or compressor damage

I did 55% @ 3900 for a couple of minutes. I about crapped my pants when I noticed it... my first thought was to run. I got lucky and there was no damage:shakehead . I seriously thought about modding an Ohmeda Oxygen analyser (has built in adjustable alarm set points) to control a solenoid on the Oxygen supply line. I got as far as getting all of the parts, which are still sitting in a box in my shop.

 

[oxyhacker]

A solenoid cut off is really nice, if you have an analyzer that can trigger it, but there are easier, lower tech ways to get some of the same benefits. The Nitrox Stick people supply a lockable needle valve instead of an orifice, and say to adjust it so that the mixer will deliver 40% when the regulator is cranked up as far as it goes, so it cannot accidently or intentionally be set higher. We recommend in the book putting washers or a spacer sleeve over the threads of the adjuster screw to limit its travel so it won't go over 40%, which accomplishes the same thing very simply.

I did 55% @ 3900 for a couple of minutes. I about crapped my pants when I noticed it... my first thought was to run. I got lucky and there was no damage:shakehead . I seriously thought about modding an Ohmeda Oxygen analyser (has built in adjustable alarm set points) to control a solenoid on the Oxygen supply line. I got as far as getting all of the parts, which are still sitting in a box in my shop.

 

[pescador775]

Two years ago, I posted pics of a modified 60 psi Harris regulator with a relief valve. I disassembled the reg down to the brass body. Then, the body was drilled and tapped 1/4 inch npt. An ordinary, brass relief valve (like for a shop compressor) was adjusted to blow at 40 psi and installed into the body. The Harris reg was reassembled and put into service. In this setup, when oxygen reaches 40%, the valve discharges oxygen (whoosh). This prevents inadvertent over enrichment but does nothing for the situation if power should go off and the stik fill up with O2. However, I am in attendance while the compressor is running mix.

The old style, medical grade, chrome plated, modular valves are just terrific pieces of equipment for the DIY. They are very amenable to modifications. I have one with a scuba yoke which is appropriate when carrying emergency oxygen in a scuba tank. The tank can be used for in water recompression or, using the Harris reg, treatment on deck.

 

[omar]

...... We recommend in the book putting washers or a spacer sleeve over the threads of the adjuster screw to limit its travel so it won't go over 40%, which accomplishes the same thing very simply.

Too crude for me... It also is not foolproof. This is the only problem I had in 7+ years of continuous blending (it was early in my learning period). It just reinforced the need to pay attention to what am doing.

I do like the idea of using a pressure relief valve. I suspect that I will get around to installing the solenoid before I do either of these options.

 

[omar]

and a pic of an older setup that I had....

 

[waterpirate]

Hi all,
I am glad I started this thread as it is continuing to answer questions. I have built my stick, and I am ambarassed to inform you all that it does not fit in my commpressor room vertical!!! WADAIA!
Has anyone installed horizontal? I think no big deal, commpressor sucks, introduce 02, filter keeps out bugs. Input please.
p.s. sorry about my jumbo avatar, i have been trying to get it up for weeks, maybe I will learn to edit size today if it snows.
Eric

 

[rjack321]

Don't worry about it, mine's at a 45-deg angle and its works like a champ. Keeps my inlet filter from being out of reach.