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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Support Equipment For PCP/HPA/CO2 => Topic started by: Joe Brancato on February 09, 2016, 09:57:20 AM

Title: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: Joe Brancato on February 09, 2016, 09:57:20 AM
I post this as Safety Notice.   I am reading in more than one instance where people are putting molecular seive into a bare aluminum housing for the purpose of filtration.  This isn't just happening with filters, but now I see it being done with a particular compressor that has come to market. 
This is wrong on so many levels, SAFETY & FUNCTION:

Please, don't mention particular brands. This is NOT about any particular product (Fllter or compressor). This IS about why not to loosely put molecular sieve into a filter tube (or similar). 

To save time, I copied, edited to remove any brand information, and pasted this:

Function:
1) Moisture serparation works best at High Pressure. When filling a tank with an inline filter, ensure the filter has some kind of the proper valving mechanism to allow the pressure to build up (this changes the dew point), prior to flow through the filter. The pressure needs to be held back up inside the filter to a point, and then allowed to flow through the filter media.   Also the filter media needs a "dwell time" as well as high pressure to work best. Simply running air through a cylinder with a filter element doesn't work well, and using loose packed beads doesn't work at all. Make sure the filter has the proper valving to allow pressure to build up before the air runs through it.

2)  Filters require a place to let out the condensate.  All filters have a condensate drain.   If the filter is working, it should be collecting moisture and it needs to be let out immediately.  Letting the condensate sit in the filter allows the moisture to saturate the filter media, rendering it useless in no time.
 
3) One can't just pack beads in a cylinder for 2 VERY important reasons.
A) It doesn't work because of "Channeling" :  We'd all like to just make a filter that uses cheap beads packed in a cylinder, but the first issue is that without proper packing, "channeling" will occur between the media. Simply put, channeling is the situation where air just goes around the individual filter "beads" instead of being "scrubbed". In order to work, the media need to be properly "jam packed" into the a container element, and this filter element put in a filter tube. Filter elements are manufactured to be "jam packed". Putting the media into a tube doesn't pack it tight enough to prevent channeling at high pressures.  Replacement filter elements are inexpensive, so it isn't an issue.

B) Most importantly SAFETY.   NEVER make a high pressure filter where the filter material directly touches the cylinder walls of a high pressure filter. This is filter element 101. The moisture in filter media leaches acid, and hence must not come in direct contact with the filter tube. Acid that leaches out will eventually make it to the walls of the vessle and threads on the end-caps of the filter, weakening them, and eventually causing the high possibility of catastrophic failure. This point can't be stressed enough. 
 
Points A) & B) are why every high pressure filter uses media that is jam-packed into either a plastic or stainless steel sleeve. So it works, and works SAFELY!
 
We would rather see you use no filter at all, and ruin an airgun, that use an unsafe product, and risk the dangers of doing so.
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: BigTinBoat on February 09, 2016, 10:09:30 AM
I post this as Safety Notice.   I am reading in more than one instance where people are putting molecular seive into a bare aluminum housing for the purpose of filtration.  This isn't just happening with filters, but now I see it being done with a particular compressor that has come to market. 
This is wrong on so many levels, SAFETY & FUNCTION:

As long as we are talking about safety using compressors, If you are using an electric driven compressor and your 20amp circuit breaker keeps tripping, don't just go out and spend $10 to purchase a 30amp breaker and replace it.....no matter WHAT #'s are written on your breaker panel.
When houses are built the breakers are size appropriate for the wiring on each of the circuits according to building codes, and are inspected prior to occupancy. Overloading a circuit via the increase in breaker amperage has a GREAT risk of FIRE.
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: Joe Brancato on February 09, 2016, 11:10:16 AM
I post this as Safety Notice.   I am reading in more than one instance where people are putting molecular seive into a bare aluminum housing for the purpose of filtration.  This isn't just happening with filters, but now I see it being done with a particular compressor that has come to market. 
This is wrong on so many levels, SAFETY & FUNCTION:

As long as we are talking about safety using compressors, If you are using an electric driven compressor and your 20amp circuit breaker keeps tripping, don't just go out and spend $10 to purchase a 30amp breaker and replace it.....no matter WHAT #'s are written on your breaker panel.
When houses are built the breakers are size appropriate for the wiring on each of the circuits according to building codes, and are inspected prior to occupancy. Overloading a circuit via the increase in breaker amperage has a GREAT risk of FIRE.

Yes, as a former Engineer/Physicist that worked in a Lightning Simulation Laboratory utilizing hundreds of thousands of Amps, and millions of volts, swapping for a larger breaker,  without upgrading the wiring is rather disconcerting.  But then, the stuff we used to do in that lab.......
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: mobilemail on February 09, 2016, 05:04:32 PM
I post this as Safety Notice.   I am reading in more than one instance where people are putting molecular seive into a bare aluminum housing for the purpose of filtration.  This isn't just happening with filters, but now I see it being done with a particular compressor that has come to market. 
This is wrong on so many levels, SAFETY & FUNCTION:

As long as we are talking about safety using compressors, If you are using an electric driven compressor and your 20amp circuit breaker keeps tripping, don't just go out and spend $10 to purchase a 30amp breaker and replace it.....no matter WHAT #'s are written on your breaker panel.
When houses are built the breakers are size appropriate for the wiring on each of the circuits according to building codes, and are inspected prior to occupancy. Overloading a circuit via the increase in breaker amperage has a GREAT risk of FIRE.

Yes, as a former Engineer/Physicist that worked in a Lightning Simulation Laboratory utilizing hundreds of thousands of Amps, and millions of volts, swapping for a larger breaker,  without upgrading the wiring is rather disconcerting.  But then, the stuff we used to do in that lab.......

Is that when you lost your mind and thought you could make a living selling air guns?   :)
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: Joe Brancato on April 13, 2016, 11:26:21 AM
Is that when you lost your mind and thought you could make a living selling air guns?   :)

Yes, I discovered how to quite easily make a small fortune in airguns.  Start with a LARGE fortune,... and invest in airguns.  :-)
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: BigTinBoat on April 13, 2016, 12:18:27 PM
I thought it was kinda funny how the guy selling the Chinese compressors remarked that this post was pretty much an "advertisement" and to basically not put much faith in it, but then there is a guy who has performed countless "upgrades" to one of "his" compressors and when looking at those posts I found a pic of "his" air dryer after apparently little use at all.

Here is the of the inside of dryer. Look at the metal where it was "protected by the threads, and then look at the metal where the desiccant was in DIRECT CONTACT with it.
(http://i1204.photobucket.com/albums/bb403/guykuo1/airmax%20compressor/air%20dryer%20interior%20corrosion_zpstb7wtk9w.jpg~original)

Here is a pic AFTER the corrosion has been cleaned
(http://i1204.photobucket.com/albums/bb403/guykuo1/airmax%20compressor/water%20separator%20interior_zpspjpdpges.jpg~original)

I wonder how many guys with these compressors are checking this?
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: Joe Brancato on May 31, 2016, 04:40:25 PM
Yeah, funny how much corrosion occurs when the beads are in direct contact with the aluminum, which is why we don't make them that way, nor the SCUBA shop compressor companies.  I can't imagine why a company would make a unit they know is designed in an unsafe manner.


I thought it was kinda funny how the guy selling the Chinese compressors remarked that this post was pretty much an "advertisement" and to basically not put much faith in it, but then there is a guy who has performed countless "upgrades" to one of "his" compressors and when looking at those posts I found a pic of "his" air dryer after apparently little use at all.

Here is the of the inside of dryer. Look at the metal where it was "protected by the threads, and then look at the metal where the desiccant was in DIRECT CONTACT with it.
(http://i1204.photobucket.com/albums/bb403/guykuo1/airmax%20compressor/air%20dryer%20interior%20corrosion_zpstb7wtk9w.jpg~original)



Here is a pic AFTER the corrosion has been cleaned
(http://i1204.photobucket.com/albums/bb403/guykuo1/airmax%20compressor/water%20separator%20interior_zpspjpdpges.jpg~original)

I wonder how many guys with these compressors are checking this?
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: chiro972b on May 31, 2016, 06:21:22 PM
I tried to explain this on another forum where folks were touting a filter that is sold for less than your alpha and it is simply media in an aluminum tube. Unfortunately, I was blasted as a shill and was told I was fear mongering. Kudos for trying to educate folks, but until someone is seriously injured using that specific filter, it seems it will fall on deaf ears.

PCP's are not a cheap endeavor and unfortunately, people are cheaping out and I fear someone is going to be hurt.
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: Joe Brancato on May 31, 2016, 06:39:23 PM
I totally understand. Unfortunately that forum is tightly controlled by the maker of that filter, hence any mention of doing it the safe and proper way (or using my product) is denounced. Thanks for pointing out the oxidation and obvious consequences.   

I tried to explain this on another forum where folks were touting a filter that is sold for less than your alpha and it is simply media in an aluminum tube. Unfortunately, I was blasted as a shill and was told I was fear mongering. Kudos for trying to educate folks, but until someone is seriously injured using that specific filter, it seems it will fall on deaf ears.

PCP's are not a cheap endeavor and unfortunately, people are cheaping out and I fear someone is going to be hurt.
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: T3PRanch on August 25, 2017, 02:18:27 AM
Why not use Activated Alumina? It doesn't break down and produce acid which attacks the metal of the pressure vessel.
Delta Adsorbents carries it for a very reasonable price!

Thurmond
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: phoebeisis on January 21, 2018, 12:46:07 PM
Catastrophic failure-as in 4000 psi metal cylinder grenading??
Yikes
Oh I am obviously getting old
I initially read Thousands of amps and Millions of volts in a Lighting simulation  lab??
I thought what they *(&^ kind of lighting is THIS!!
Then I read more closely-LIGHTNING LAB! 
OH!
Charlie
Title: Re: SAFETY NOTICE: Molecular Seive used in Aluminum Cylinders
Post by: Taso1000 on January 21, 2018, 03:50:36 PM
Hi All,

I have also been trying to find information on this exact issue.  In the name of safety I will add what I have found through my research on the internet. 

But as we all know, just because it's on the internet does not mean it has been verified.  I have found it very hard to find multiple sources backing up my findings.  So please take it as just additional information to make a decision or to drive you to seek out more information. 

It would be great if you could also post your findings here so that we can find the true facts.   :)

These excerpts are from this thread:

https://www.gatewaytoairguns.org/GTA/index.php?topic=126349.msg1280872#msg1280872 (https://www.gatewaytoairguns.org/GTA/index.php?topic=126349.msg1280872#msg1280872)

Quote
Re: Chinese High Side Filter Dryer Hack
« Reply #87 on: July 23, 2017, 01:01:43 PM »
QuoteModify
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/ (http://alcancylinders.com/aluminium-cylinders-vs-steel-cylinders/)
Quote
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/ (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 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

I forgot some information and added this post:

Quote
Re: Chinese High Side Filter Dryer Hack
« Reply #88 on: July 23, 2017, 01:12:52 PM »
QuoteModify
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

Here is one link discussing the formation of acid creation of molecular sieve and oils used in refrigeration:

https://www.qwik.com/education-and-training/articles/acids-in-refrigeration (https://www.qwik.com/education-and-training/articles/acids-in-refrigeration)

The polyolester oils used in refrigeration systems interaction with molecular sieve is the only information that I have found multiple instances that all agree.

I don't have enough information to make a conclusion.  But it doesn't take a whole lot of expense and time to keep the media from contacting the aluminum. 

My intent is the safety of the airgun community and sharing what I have found. 

Be safe!   :)

Taso