Partial pressure blending on my compressor

[SentinelAce]

I have been looking into a nitrox stick but a few people told me participial pressure blending is the better way to go to get the % of gas that I want to mix. Mostly 32% but was curious if I could do 50% by using this method? I'm curious where to start and I assume you may need more details

 

[tbone1004]

well it's partial not partical *particle?* or participial *a term for grammar IIRC*, but I'm not sure who told you that partial pressure *PP* blending is the better way to go.
Important points
PP blending is dumb unless you have specific circumstances that make it acceptable-i.e. I own a booster and have free access to an air compressor so PP blending makes sense for me. If I had a compressor *well I technically own 2, but it's more convenient to use the fire departments booster* I wouldn't PP blend
You can't mix nitrox greater than 40% through the compressor without risk of it exploding so if you want 50% you have to PP blend that
Buy the oxyhacker companion and some of the other Vance Harlow books because they're very useful for this sort of thing and read through the compressor threads on here. Most all of the info you seek is already here

 

[broncobowsher]

I'll second the Oxyhacker handbook as an initial reference tool. I have an ancient copy. Still useful.

 

[clownfishsydney]

For mixes up to 40%, oxygen stick is the only way to go as you don't waste any oxygen. For higher, do a combination of partial pressure and oxygen stick. Not hard to work out a spreadsheet to figure it out for you.

 

[BoltSnap]

For mixes up to 40%, oxygen stick is the only way to go as you don't waste any oxygen. For higher, do a combination of partial pressure and oxygen stick. Not hard to work out a spreadsheet to figure it out for you.

Yes!!

 

[RayfromTX]

For mixes up to 40%, oxygen stick is the only way to go as you don't waste any oxygen. For higher, do a combination of partial pressure and oxygen stick. Not hard to work out a spreadsheet to figure it out for you.

There is an app for that. I use "trimix tools".

 

[Chris H]

I recently built a Nitrox stick after owning my compressor for 10 years. It was fun to build, and works great! I have a Haskel AG-30 as well, but for filling OC cylinders with 32% the stick is definitely the way to go. I haven't done anything higher than 32% with mine.

 

[Billy Northrup]

I keep two cylinders of O2 on hand, the fresh one is ude to top off deco tanks and then demoted to empty almost completely into the stick

 

[BoltSnap]

I recently built a Nitrox stick after owning my compressor for 10 years. It was fun to build, and works great! I have a Haskel AG-30 as well, but for filling OC cylinders with 32% the stick is definitely the way to go. I haven't done anything higher than 32% with mine.

How much did the entire project to build it cost you, end to end? How reliable is your system and can you change the mix % easily?

 

[Chris H]

How much did the entire project to build it cost you, end to end? How reliable is your system and can you change the mix % easily?

I don't know exactly, I am terrible at keeping track of money when I'm doing fun things. It was probably <$200. I bought a regulator ($79) and a flowmeter ($61). The Oxygen analyzer on the stick is an original PPO2 display from my KISS Classic CCR. I'm using the same cells in the stick as I do in my rebreather. It is a piece of PVC with a piece of perforated sheet metal in the bottom that supports 8 or so practice golf balls. The filter on the top is from a shop air compressor.
The mix is very easy to dial in with the flowmeter. The total build cost will vary some depending on the amount of stuff you already have, and how resourceful you are.