Questions about filtration

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opie712

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Location
Cookeville, TN
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I have been reading through some old threads regarding nitrox continuous blending right now the only filter I have on my bauer compressor is the PO filter, some was saying that they were blending with only the PO filter and just doing more frequent filter changes. Im almost 100% positive that my filter bauer brand said grade D and LF website confirms theirs is grade D. I was under the impression that isn't adequate filtration for o2, am I wrong you don't need OCA air to continuous blend that the PO would be enough. if the PO isn't enough would a 16" or a 33" tower work.
 
Get your air tested. That's the only way you'll know.

FWIW Both of my Bauers with stock filters exceed "OCA" or "NAUI modified" or whatever other pseudo-standard that I'm supposed to meet for O2 clean air.
 
I have no idea what you are actually saying or asking, but my standard Junior II is used for making Nitrox via an oxygen stick. Never had a problem in 12 years.
 
Bauer has used the PO filtration, as standard filtration, on units up to the Mariner II, which has a "fill rate" of 8 cfm. If you use their conversion sheet to calculate processing capacity at 90 F ambient temp (105 F inlet), you will only get 43% of rated capacity. The PO has a max capacity of 3200 cf @ standard inlet conditions. 3200 x 43% = 1376 cf. Now multiply the compressor out put 8 cfm by 60 and you get the cfh of the compressor, 480 CFH. 1376 divided by 480 = 2.86 hrs of run time before the filter is expired. Grade D is the best you will get from PO filtration.

You can plug in the out put of your compressor to figure the max run time on the PO.
 
Bauer has used the PO filtration, as standard filtration, on units up to the Mariner II, which has a "fill rate" of 8 cfm. If you use their conversion sheet to calculate processing capacity at 90 F ambient temp (105 F inlet), you will only get 43% of rated capacity. The PO has a max capacity of 3200 cf @ standard inlet conditions. 3200 x 43% = 1376 cf. Now multiply the compressor out put 8 cfm by 60 and you get the cfh of the compressor, 480 CFH. 1376 divided by 480 = 2.86 hrs of run time before the filter is expired. Grade D is the best you will get from PO filtration.

You can plug in the out put of your compressor to figure the max run time on the PO.
That's what I thought grade D wouldn't work for nitrox would getting a 16" or 33" tower and use the PO to pack be a good choice if I wanted to start blending nitrox
 
Is this a valid comparison of Grade "D" vs Grade "E" air ?

Compressed Air Quality Test: Grade D, OSHA 1910.134

The only difference I see is that Methane content for "E" is specified (and the O2 component is a bit tighter)

I would have thought Hydrocarbons would have been the biggest concern, what am I missing ?

(I do understand Methane is a hydrocarbon, should have been more specific and said oil/particulates)
 
With methane, Grade D testing doesn't track it, while Grade E has a specific limit. Grade D is usually associated with portable compressors used for scuba, which tend to have minimal capacity filtration in order to be portable. Methane being a flammable gas, I would want to know the content in the air in which I intend to introduce O2.

Grade E will work for blending O2. The question is, will Grade E be maintained through out filter life? Most folks sample after a new cartridge is installed. In certain conditions, a new filter may return a failed result for high O2 under the Grade E standard. Kind of a PSA situation going on. But simply putting a few hours on the filter before sampling will allow everything to gel. What we really should be concerned about is what is the air quality on the down side of filter life. If you think about it, a single air test at the beginning of filter life, really means nothing.

Also, there are folks that over run filter life.
 
. Methane being a flammable gas, I would want to know the content in the air in which I intend to introduce O2.

I can pretty much guarantee that there will be more methane in the O2 than in the air so that's pretty much an non-issue.
 
I can pretty much guarantee that there will be more methane in the O2 than in the air so that's pretty much an non-issue.

So what is the big deal about Grade "E" air? The shops I've been to take it as a matter of religion that if your tanks are O2 clean, filling them even once with Grade "D" air hopeless contaminates them.

And if methane is used as a marker for general hydrocarbon contamination, what would be the source given the oil/particulate level is held to the spec'd level ?
 
I can pretty much guarantee that there will be more methane in the O2 than in the air so that's pretty much an non-issue.

How so? I tend to not trust this kind of claim. What basis do you have for making it?
 
https://www.shearwater.com/products/teric/

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