Question Filter for Compressor to Produce O2 Compatible Air for individual use

[rhwestfall]

Clear as mud....

 

[macado]

I dont pretend to be an expert in any of this but those small personal filters that attach to DIN whips may not be adequate enough depending on the size of your compressor. Without a Priority Valve (Back Pressure Valve) there really is not enough dwell time in the filter stack. I would probably consider just adding a secondary filter tower in series with your existing one.

In some cases you'll likely meet Oxygen Compatiable Air (Modified Grade E) standards without having to do anything special. From my understanding it is not a very hard standard to hit and most SCUBA/SCBA-rated compresssors will produce it out of the box, at least for a short period of time depending on their filter stack.

I can only speak in terms of my personal 100LPM (~3.6cfm) compressor.

It is sometimes merely just a matter of testing for that standard. My Alkin W31 processes OCA standard out of the box but I've also added a larger filter stack on it for redundancy.
I tested (the last 3 times) specifically NOT going through my secondary filter stack because I wanted to see the worst quality gas my compressor would produce with X number of hours on the filter before I changed it.

At least for me I use the primary filter on my Alkin W31 (P21-style with 13X dessicant) for drying and then I use an additional 10" filter tower with an X65240 cartridge that contains more 13X, activated carbon and hopcalite.

This is what I am using. I also have a priority valve after the 2nd filter stack which is set to 150 bar (~2200psi)

Lawrence Factor Cartridge Holder PU-530001-AF

The PU-530001-AF Lawrence Factor is an Breathing Air, Drying Gas, Odor & Gas Sweetening absorbent cartridges holder for X53 Series

filtertechs.com

Mako Breathing Air Filter PC-1801, X65240

The X65240 filter cartridge is guaranteed to match the fit and performance of the PC-1801 OEM cartridge.

filtertechs.com

X65240 is designed to filter ~10,000cu/ft of gas however that is largely based on air temperature. I tend to change this filter out around ~40-45 hours.

From FilterTechs:

The X65240 will process 10,000 c.f. of Air as long as the Air inlet temperature going into the Filter tower is 80 (F)

The Air temp entering into the Filter tower will generally be about 10 - 15 degrees hotter than the ambient temp the compressor is operating in. So if the ambient Air temp is 80 then your Filter tower inlet temp will be between 90 - 95.

This will reduce the capacity by about 70%. So instead of 10,000 you would get about 7,000.
If it’s hotter than that you may only get half the the total.

 

[Tracy]

The ugly truth that nobody likes to hear is filters don't make air clean.
A properly designed air system will make oxygen compatible air with zero filtration installed provided with clean incoming air.
Filters are used to INSURE air quality. When the neighbor starts their charcoal grill, or a car pulls up and idles outside for a few minutes, the filter takes over and removes the CO by turning it into CO2.
If your compressor will not pass for OCA with NO FILTERS installed, it should be redesigned so that it does.
Filters are also used to make clean air on a cheap poorly designed machine. This will eat filters and you are playing with fire, sometimes literally when the moisture gets too high.

Again, filters should not be removing moisture and oil from your breathing air. They can lower the dewpoint further, but using mechanical separation only, it should be low enough to pass for OCA.

 

[happy-diver]

Filter Systems « Midland Diving Equipment Ltd

www.midlanddiving.com

Yes Just another invention to suck the money out for no reason

I've seen dive shops with one of these aluminium things plumbed in seperately after everything with a
bypass valve, and if you ask for "clean" air they run your air through it and charge you extra ooh ahh!!
With No PMV

One other dive shop owner never drained the condensate from his Grade E air filter, it was seized shut
The sieve was like the clay from Ghost ooh ahh!!

The skinny long inline filter that you screw in to your fill hose, is completely useless, also with no PMV

Compressor Filter System Theory - Scuba Engineer

High Pressure Breathing Air Compressor Filtration System Design author:- Stephen E Burton BSc(hons) C.Eng, MIET - Email to:- scubaengineer@gmail.com

scubaengineer.com

Pressure Maintaining Valve

Yeah I partial pressure blend with straight from the filter air all Bauer stuff normal dry air
pack all my own filters and weigh for moisture or B timer or Securus or whatever or not

 

[rhwestfall]

This is likely an ignorant question, but I can't seem to find the answer. I can get close, but not quite there.

Is Grade E generally considered to be OCA?

My test results didn't specify OCA. Up to now I have only pumped air, so wasn't really relevant.

Again, maybe a simple thing I am overlooking. Thanks!

DW

 

[iain/hsm]

Clear as mud....

ROFL very funny

But to understand the table fully do I need to add PSI or Bar to those numbers or will either of them do?

 

[clownfishsydney]

For 20 years I have been making Nitrox using my Bauer Junior II compressor. For under 40% I run oxygen through the compressor using an oxygen stick. For over 40%, I partial pressure blend. No need for any additional filtering so long as you have a good filter in the first place. I have a repackable one.

 

[gkis]

@rcontrera is the guy to ask about this thing

Personal Scuba Filter · DIN 300

Do you worry about air fill quality when diving? The Personal Scuba Filter mounts easily between DIN 300 tanks and the compressed air source. Produces Grade E breathing air by removing moisture, hydrocarbons, oil, taste/odor, and converts CO to less dangerous CO2.

nuvair.com

These things are not very cost effective though as the filters need to be replaced very often, they are cycled every time you fill which isn't great, they're rather big, and you MUST be filling directly from a very small compressor or you will exceed their flow rate and then there is not enough dwell time to bother. Your compressor is on the upper limits of fill rate for example so you have to be filling directly.

For the cost it really isn't that much more to add another filter to the compressor like what's linked below that would be much more economical in the long run. In that case since you're in a fairly humid area you would have your first tower filled with a drying cartridge that is replaced much more often than the filtration cartridge in second slot and would make the drying cartridge repackable. Way more cost effective.

MCH3-MCH6 Filter Tower Add-On Kit

This filter tower add-on kit is designed for use on Coltri MCH3, MCH4, and MCH6 compressors that were purchased without filtration capabilities. This kit is comprised of OEM tubes and connectors and includes an SC000340-M filter element.

nuvair.com

tbone, Ray Contrera passed away sometime last year, RIP , I just found out today while making some enquiries with Nuvair.