Chinese High Side Filter Dryer Hack

[gendoc]

I bought one of the Xin Yong Shi filters for my Carette compressor after reading Rod's post on a different forum.  A local friend who recently bought an Air Venturi compressor also ordered the gold filter.  Both filters only took a week to arrive from China via DHL.  That's faster processing and delivery than I get from most U.S. vendors.   I really enjoy reading this thread and appreciate all the ideas you guys are sharing.  I set up both filters with 1" endcap sections of tampon cut from the supplied filter material and the 13X desiccant ordered from Rod's recommended Ebay supplier.   

When I first read about the PVC liner/o-ring insert hack I made one for  the filter while waiting for it to arrive.  When it arrived and I realized that there was a noticeable gap between the PVC and filter wall I was concerned that the PVC would either crack due to expansion pressure or leak around the o-rings.   My own feeling is that the extremely small amount of moisture that enters the filter through the tiny center entry hole is absorbed by the tampon or 13X molecular sieve and almost no moisture ever contacts the filter walls before being absorbed by the tampon/desiccant.   My feeling is that the "toxic acid" created by moisture reacting with the desiccant which will eat through the anodized coating, aluminum walls, and threads of the filter is mostly marketing hype.  The vendor who sells $400 filters and $40 filter replacement packs is not an unbiased source of the gospel when it comes to facts about filters.   The Xin Yong Shi filter is nearly identical to the Diablo filter sold by AofA which does not use cartridges and also uses desiccant beads.   No one using Diablos has ever reported any sign of chemical reactions or exploding filters.

I'm not advocating anyone removing their PVC inner liners from their filters.  It doesn't hurt anything and it provides you owners with a level of comfort which I understand and appreciate.  I will monitor my filter and report my findings as a source of information
and sharing of ideas on another approach.  If I see any chemical reaction to the anodized coating or threads I'll report my feedback.

If it turns out that a liner is necessary I've also researched a local aluminum tubing distributor which sells 1.375" outer diameter, 1.250"ID pipe.   My digital caliper won't reach far enough inside the filter to give me an exact reading but if it fits it would be a more
precise fit  to the 1.250"OD PVC you guys are using.   If it works I was thinking of getting enough of them made up to provide to Xin Yong Shi filter owners who might be interested.   I'm just not sure how necessary they are.   

Has anyone found a way to get the exact inner dimension of your gold filter housing?

so your belief is, no need for the pvc & o-rings....your just using 1" endcap sections cut from the supplied filter material and filling the tube with the 13x ?

interesting !! and your going to monitor the aluminum structure from within the inside
 of the filter housing and end caps ?

i can see where your coming from....hopefully no reaction will take place inside the filter housing. time will tell, thanks for your thoughts 

[Bizill]

I have borescopes at my work but didn't feel the need to measure the I.D. of the tube.  That is, until today.

I'm sorta leaning toward what Humdinger is saying.  The diablo uses no liner.  The Carette factory HP filter uses non liner.  I'm starting to think it's hype.

And regarding the pvc tube, unless I need to elongate my pvc tube by a mere mm or 2, I see moisture getting around the o-rings and pvc pipe.  My first results may have been skewed due to the fact that I didn't check too closely for moisture.  I know my tampon like element was dry on the output side of the Gold HP filter but just now I ran a cycle with my 2.17 liter scba and quickly unscrewed my Gold filter and found moisture.  Moisture that goes outside the pvc vs through the sieve.  I may make another tube just a butt hair longer or look for something that fits exactly the I.D. of the tube.  Or I may just not use a separator at all.

Why does the Alpha filter use in inner tube if not due to corrosion?  How else would you separate the molecular sieve from the activated charcoal and keep them from mixing together?  You'd need a removable tube and that also makes for expensive, but easy replacement.  Sounds lucrative to me. 

I might just go the route of using a tampon like filter in my black filter that came with my yong heng.  Then get another small separator for charcoal.  Then fill up completely my big gold filter with molecular sieve with a tampon on each side to keep the sieve from traveling through the fittings.

[fxtrapper]

I have been thinking myself there is no way that the pvc and O-rings will hold to 4500 psi. I understand the thinking behind it and the thoughts of the sieve material damaging the aluminum but it is anodized and they do anodize things for the protection of the aluminum. It just looks to me as an extra step for the filter that is not needed. I do not want to step on any toes or make anyone mad by any means because the thought process behind this is really creative I am just wondering if it is really needed. Also I do know that the smaller tampon black filter supplied with the Yong Heng does not stop water I turned mine on yesterday under no load and it was spewing water for the first 10 to 15 seconds it ran. I will not fill anything else till my filter and sieve material arrives.

[YEMX]

What's the reaction between the 13x filter material, and the aluminum?  I'm also not wanting to step on toes- I just don't know.  Also, would a different type of anodizing be better?  It's not a cheap option, of course- but I'm just wondering if one were so inclined as to have the tube re-anodized from a better company, would it matter?  What about an epoxy paint, like Cerakoat?  Would that work?

I'm just throwing out ideas- I'm not trying to make anyone mad...

[Humdinger]

I have borescopes at my work but didn't feel the need to measure the I.D. of the tube.  That is, until today.

I'm sorta leaning toward what Humdinger is saying.  The diablo uses no liner.  The Carette factory HP filter uses non liner.  I'm starting to think it's hype.

And regarding the pvc tube, unless I need to elongate my pvc tube by a mere mm or 2, I see moisture getting around the o-rings and pvc pipe.  My first results may have been skewed due to the fact that I didn't check too closely for moisture.  I know my tampon like element was dry on the output side of the Gold HP filter but just now I ran a cycle with my 2.17 liter scba and quickly unscrewed my Gold filter and found moisture.  Moisture that goes outside the pvc vs through the sieve.  I may make another tube just a butt hair longer or look for something that fits exactly the I.D. of the tube.  Or I may just not use a separator at all.

Why does the Alpha filter use in inner tube if not due to corrosion?  How else would you separate the molecular sieve from the activated charcoal and keep them from mixing together?  You'd need a removable tube and that also makes for expensive, but easy replacement.  Sounds lucrative to me. 

I might just go the route of using a tampon like filter in my black filter that came with my yong heng.  Then get another small separator for charcoal.  Then fill up completely my big gold filter with molecular sieve with a tampon on each side to keep the sieve from traveling through the fittings.

Bizill,  please post your inner dimension findings after you measure.  I'm hoping that a 1.375" aluminum liner fits without scraping or binding.  If so it could serve as a liner if needed.   I just don't believe an inner liner is required.   Logic tells me that an owner would have to neglect the filter changes for an extended period before the slightest bit of chemical reaction "possibly" occurs.

There is a simple way to include activated carbon and 13x molecular sieve in a filter.  Charcoal is included in compressor cartridge filters to remove impurities from dive compressors so the air has no odors or toxins.   I do have charcoal in mine but it's overkill.   All you do is use 3 sections of tampon as spacers the same way a cartridge filter is packed.  I filled my filter 75% with 13x sieve material and used a tampon spacer to separate sieve from activated charcoal.   Charcoal can be purchased at pet supply stores or the pet section of Walmart.   I may omit the charcoal after the next time I recharge the desiccant in an oven.  I plan to run the compressor for 20 hours between filter moisture inspections.   I'll weigh the desiccant before and after to see how much moisture was removed.  I'll also visually inspect the filter walls closely for any signs of chemical reaction.  I doubt I'll find any.

Regarding the question as to why cartridge filters are sold, my thinking is that most compressors are used for breathable dive tanks and the cost of a filter is minor compared to the safety factor they provide in making sure the air is pure for breathing.   A $30 filter changed every 20 hours at a dive shop is a minor expense for them. 

I live in NASCAR country and there is a local shop that offers many diameters of aluminum tubing.  Thin walled 1.375" tubing is available.  If it turns out my assumption is wrong about toxic leeching moisture that would be my next approach if that size fits.  Let us know your measurement findings.

[Bizill]

Joe Brancato linked a story about how there exists some sort of reaction with the molecular sieve and aluminum walls and acid leeching or something or other.  It's probably even linked in this epic thread somewhere or possibly find it on Joe's website Airtanksforsaledotcom.  I'd think even if true it'd take a good long time and I'd just buy another filter.  I'm not calling Joe out, but like Humdinger mentioned, the Diablo doesn't use reusable filters, right?

I probably won't take my tube to work unless I decide to keep a liner.  Even though these are most likely cnc'd, doesn't mean all our tube will be the same exact spec, even from the same seller/manufacturer so why get anyone's hopes up.  Just wanted to mention a bore gauge is the way to go and most are deep enough to get past the threads.

There is type III hard anodizing, but who knows if that would make things better or worse.  I was thinking epoxy paint, acrylic paint and almost any other hard paint would work, but then it'd be too hard to get it perfect and not hit the threads with it. 

All I know is that I found moisture in my hp filter and I am certain some reached the scba tank.  If anything, unless we all decide otherwise, I may just lose the pvc "liner", as it doesn't line the outside wall of the filter, but add another into the mix to be certain.  These things fill so fast that an extra minute to fill the second Gold filter doesn't bother me.  What DOES bother me is the moisture.  Sure, I could lengthen my pvc like I said just by a mm or two, but right now I'm in the "see what the forum comes up with" mode.

[gendoc]

I'm in with this......."see what the forum comes up with mode" 

[Taso1000]

I have been doing a lot of research about molecular sieve lately.  Initially it was concerning the different pore sizes and what worked best at removing only water. 

While I was gathering information I read on a forum and saw a video from a professional in the business that molecular sieve produces acid when it interacts with water.  From what I have found so far this is not entirely true.  The only instance that I have found so far where acid is created is the interaction of molecular sieve and polyolester oils used in refrigeration systems.  This does not apply to hpa compressors.

I have also read that carbonic acid is formed in molecular sieve and water.  I have not found any scientific confirmation of this yet.  But I did research how carbonic acid would affect aluminum.  It doesn't.  http://alcancylinders.com/aluminium-cylinders-vs-steel-cylinders/ 

2) Aluminium cylinders, on the other hand, are not affected by carbonic acid, and no corrosion will occur.
Carbon dioxide gas reacts with water to form carbonic acid. According to the ASM( American Society for Metals) Metals Handbook (1, 2, 3), aluminium and  brass are not attacked
by carbonic acid, but steel will corrode.

 

I also found that when water contacts molecular sieve it causes an exothermic reaction. 
 Heat is created.  https://dftechniek.wordpress.com/2017/06/06/reaction-of-molecular-sieves-with-100-water/  I don't know how much heat is created but as we all know air expands when heated.  If 4500 psi air were heated that would cause a catastrophic over pressure condition and someone could get hurt. 

Since I am talking about safety, I recently contacted Airguns of Arizona to see if the Diablo filter they sell had a pressure certification.  They responded that the Diablo filter had been tested by Raptor Pneumatics and the burst pressure was 16,200 PSI.  the certificate is available from Raptop Raptor Pneumatics.

So like I stated earlier I have just started collecting information and I'd like to share it with forum members.  I have nothing conclusive but I hope we can share information we have found to make better plans in water removal.

Thank you,

Taso

[Taso1000]

I forgot to add.  I did find that molecular sieve itself is acidic.

Also I think keeping the cartridge is a good idea for many reasons regardless of acid creation or not.  First it is convenient and faster to replace a cartridge.  This exposes the media less to air while handling so its capacity isn't used up by filling the filter.  Also it keeps the media contained so dust and particles don't get everywhere.

It would be nice to be able to regenerate the media while in a cartridge but I don't think the plastics will survive 500 degrees.  Maybe the sieve could be regenerated at 250 degrees but for a longer period of time?

Thanks,

Taso

[shultz]

256mm was the number for my length of PVC to insure the O rings compressed and sealed. I cut one before my filter even delivered at 253mm, the O rings may have been touching the end caps at this length but not compressing and sealing...

I've also added some UHMW, sticky back sheet I had to each end of the PVC. One full wrap to where each end of the sheet stock meets takes up the gap and provides a press in fit for the PVC tube. Don't ask where I got this stuff, I have no recollection of how or why I acquired it....

I have found ZERO moisture at the outlet of my gold filter. I also check the fill whip, and fosters after each run for any moisture. When I fill my scuba tanks, I check the fill block and valve face. I have yet to see any evidence moisture has made it into my tanks.

On the other hand, my black stock filter that is now my pre filter is wet even with frequent water bleeds(every 2-3 minutes). The inlet end cap on my gold filter has had some moisture on the face, the 1" section of filter material has been damp on the inlet side but felt dry on the side touching the sieve. I inspect my filter at the end of every run...

All this leads me to believe I'm not putting moisture into my tanks.

Another option in place of the PCV tube. I wish I could find the thread again... Anyway, the poster, used flexible kitchen cutting mat to form a liner. He cut, then rolled it so it perfectly fit the tube between each end cap, then slowly pulled it out and sealed the seam with tape. Once done, he had a perfectly fitting liner that retained its size. He didn't use additional O rings, just a chunk of the stock filter material at each end and sieve in the middle.

No matter how you go about filtering out moisture, just make dang sure its doing the job!

[rnabholz]

Hi Guys,

I am enjoying the exchange of ideas on this topic.

As a couple of folks have raised the issue, I want to make it clear that I am not offended by others exploring alternate approaches.  The more the merrier.  I watch with interest at Humdinger's liner free experiment.  If it turns out that there is no adverse affect, great.

I just want to make a couple of points.

First, with regard to the PVC's strength and the O-rings effectiveness.  The simple fact that my PVC liner has not cracked or exploded is direct evidence that it is not holding that pressure and that the O-rings do leak.  My belief is that the O-rings do leak until the pressure inside the gold tube is equalized on both sides of the PVC.  Once that equalization occurs, I believe that the air follows the path of least resistance, that is, through the paper plug, the 13x media and out the paper on the other end.  I believe the circle marks on the paper plugs demonstrate that air is flowing that way.

It is hard to imagine air pressing through tight fit of the O-Rings, down the sides of the liner, and back through another tight O-ring and out when there is a MUCH less difficult path through the paper and media.

Second point is that I can only report on my experience with my set up.  To that end, this is what I have.

California Air Tools 1hp - 8 Gallon Shop Compressor output set at 87psi to-
25 feet of hose to-
Two Bead Dessicant Dryer/Filters () to-
25 feet of hose to=
Water Oil Separator  () to-
Shoebox Max to-
Gold Filter with PVC Liner, Paper filters and 13x Media to-
Fill rig on SCBA tank.

It is certainly true that my Shoebox Max's output is much less that some of the rigs that you guys are running, and it is likely that works in my favor as it relates to dwell time in the anti-moisture devices in my air path.  My results have been excellent, but how that relates to yours and the myriad of choices that you have made with regard to your set up is very hard to guess.

I think I am good where I am, and arrive at that conclusion by the evidence that I have shared in this post all along. But I watch with interest at the approaches you all take.

May I suggest that you all share all the details of your rigs from beginning to end so folks can get the complete picture.

Please continue to share and best wishes and good luck to all.

Rod

[Taso1000]

Rod,

We have similar requirements since we are both using Shoebox compressors.  The Chinese compressors have bleeds on the first and second stages, I believe, where the bulk of accumulated liquid water can be removed.  The Shoebox does not so we have a lot of liquid water in our output.  I am planning on adding a water trap to my Shoebox in hopes of removing the accumulated liquid water.  You can read about it at the end of my thread if you wish:  https://www.gatewaytoairguns.org/GTA/index.php?topic=120744.msg1271371#msg1271371 

Soon I will be able to try it out.   

Thanks,

Taso

[shultz]

UNSICENTIFIC, UNTRAINED OBSERVATIONS below.....


So, I just pulled down my 4 year old Ninja carbon tank. It's spent most of its life being filled with scuba shop air. It has been filled 6 times using my Yong Heng compressor and high side filter so far.

I Slowly let all the air out, about 3500psi. I had a paper towel about 2" from the outlet, tank upright as I did so. The paper towel was clean and dry when I hit zero PSI in the tank

Pulled the Regulator and did an internal Visual inspection. No, I'm NOT trained to do this....

Regulator looked pristine, not a bit of corrosion on the base or threads, O ring still in fine shape.

No water in the tank, no debris in the tank.

I dropped a segment of bright, white LED's inside the tank for illumination. All I could see was an overall uniform, grayish color to the liner and some mild oxidation on the walls of the liner. This oxidation didn't cover the entire liner, just some small patches of it(whitish spots). Now, I'm not sure its even oxidation, It does LOOK like typical oxidation you would see on raw aluminum after some time. No pits or cracks that I could see, I don't have a mirror small enough to fit inside so I could inspect the neck.

It would have been nice to have inspected this tank day one.... What I'm seeing may have been in there from the factory. Anyone who has seen a liner before use please chime in!!!

Based on what I just looked at, the high side filter is working. IF, I were putting water into the tank, surely I would have found some after 6 fills.

[fxtrapper]

Shultz after what I found by not using the gold filter you definitely would have seen moisture in the tank. It was spewing from my chinese compressor without it so I won't fill anything else till I get the gold filter. Also must add here in KY. its very very humid where I live in the summer months we run a dehumidifier in the house 75% of the time.

[Bizill]

There's that too in my case.  When I first filled my scba I saw no traces of moisture.  We were at like 15% humidity.  Yesterday I was more at like 45%.  We're in our desert monsoons.

[shultz]

Monsoon season here as well, 44% humidity this afternoon.

I'm running the compressor inside, with the A/C running I'm right around 40%. I get a good amount of water from my every 2-3 minute water bleeds. The black, stock filter is really wet on the inlet side but I don't see any moisture at the outlet. The inlet cap of my gold filter has no moisture on it, but, the inlet side of the filter does feel a little damp. It's bone dry on the sieve side and I have yet to see any moisture at the outlet of the filter, hose, fittings and now tank

[gendoc]

if your in monsoon season at 44%....we are at 95% here in the deep south.
its that way until mid october around these parts

[shultz]

And you can keep that 95% down there please

I spent several years playing in the central and south American jungles, I had my fill of humidity...among other things.

I like my summer heat like a martini, DRY

[rnabholz]

Rod,

We have similar requirements since we are both using Shoebox compressors.  The Chinese compressors have bleeds on the first and second stages, I believe, where the bulk of accumulated liquid water can be removed.  The Shoebox does not so we have a lot of liquid water in our output.  I am planning on adding a water trap to my Shoebox in hopes of removing the accumulated liquid water.  You can read about it at the end of my thread if you wish:  https://www.gatewaytoairguns.org/GTA/index.php?topic=120744.msg1271371#msg1271371 

Soon I will be able to try it out.   

Thanks,

Taso

I look forward to reading about your results.  Thanks

Rod

[FuzzyGrub]

I think I might add this to the project list.  I appreciate the info you have provided.   

I apologize if you already provided this, but was wondering how long does it take to pressurize the filter?   I typically keep the valve closed until the gauge reads equal to what remains in the tank.  If it doesn't reach 3k within a few minutes, I know I have a leak or other issue.  The filter appears to have significant volume, so wondering how many minutes with your set-up.  Thx.