Tuxing oil water separator desiccant container imploded. What went wrong?

[Eaglebeak]

IMO, leeboysf's media sequence and direction of flow are correct and how the makers intended it to be used for breathing air. The carbon's job is to remove oily and poisonous fumes before the drying desiccant to prevent the pores in the beads and crystals that absorb the moisture, from clogging. Sealing the output side, allows the whole inside to pressurise equally and the only path for any air to exit through the output hole must be through the filter cartridge. If you run it in the opposite direction, it will still work but I believe the designers meant it to be used in the way it is supplied. If you look at the pictures you can see that the carbon is at the opposite of the sealing socket. Humdingers theory that the carbon getting wet and blocking that orifice doesn't stack up, 1 because a couple of minutes run time is not enough to even dampen the first filter and 2 because for the tube to implode like that, it would have to have unblocked itself the instant you disconnected the other filter leaving a pressure difference between the inner and outer tubes. That would be impossible because you had already bled the line and any high-pressure air outside of the cartridge would have escaped then because that end has no seal between the two tubes and no seal between it and the inlet hole. I think that Humdinger assumed that the sealing end and the carbon end are both on the inlet side which you can see in the photo is not the case. I'm sorry if I am a little hard to follow, I have a mild brain injury from a cardiac arrest and drowning incident ten years ago. Anybody that has one of these filters you should be able to follow what I'm trying to explain. I must say though, I'm still none the wiser for what actually caused the thing to fail like that. If I had to guess I'd say it was an assembly error. I assume that leeboyf did not take it apart before hooking it up. I suppose that if it happens more than once, somebody will figure it out.

 

[Humdinger]

Eaglebreak, I agree with you that a short run wouldn't saturate the filter media. Previous runs saturated the media due to the tiny moisture removal towers which are too small for the fill speed of the compressor. The desiccant doesn't dry out between runs so this could have been the point where a blockage caused a pressure differential and implosion. We all agree that a pressure difference the inside of the filter occured when Leeboysf detached the second filter from the input side causing external pressure to implode the plastic cartridge tube.

My Tuxing cartridge seals with the two o-rings on the extension side of the cartridge. The o-rings on the nipple form a seal that forces incoming air through the cartridge. Leeboysf's housing is either out of spec or his cartridge had undersized o-rings.

I like the Tuxing filter and cartridge but don't like the Tuxing desiccant. The clear silica media in the 3 segment cartridge is a total waste of space. Charcoal does filter out oil smell from compressed air. Yong Heng owners can reduce the oil smell by disregarding the instructions that accompany some Chinese compressors recommending #46 hyrdraulic fluid as lubricant. It burns and it smells. Use true synthetic high pressure compressor oil and the smell of oil will greatly diminish. If you buy a Tuxing cartridge I recommend repacking it with 13X molecular sieve seeded with a small amount of colored silica beads to serve as moisture indicators. The Tuxing cartridges can be reused by repacking them with fresh media instead of buying replacement cartridges. It is an excellent filter system.

 

[airgunfans]

After going through this Youtube video showing the structure of the Tuxing filter , I think I know what has happened

https://www.youtube.com/watch?v=6SjoTB4btJY



The cartridge actually did not implode but exploded due to excessive pressure built up inside.

This picture shows the airflow inside the filter. As expected, the cartridge has an air-tight joint with the cap of the filter at one end only. At the other end, air can freely flow between the inside and outside of the cartridge to equalize the pressure :

However, pressure equalization is possible only if the air flow is slow. In the situation of the OP’s case, the air flow is extremely rapid so a big pressure differential is built up resulting in the cartridge being blown apart.

So I think the filter was basically OK. The destruction was due to disconnecting the hose while the pressure inside was still high.

As pointed out by Humdinger, the two O rings at the outlet of the cartridge should make the joint between the cartridge and the end cap of the filter air-tight. You can see in the video that the demonstrator needs to use some force in pulling the cartridge away from the end cap :

 

[Eaglebeak]

@ Humdinger. The opp claimed that all the equipment was brand new with only the two gun top offs on the clock. I have run mine for hours and in my experience, virtually nothing gets past the small OEM filter. Whenever I open the larger one for maintenance I find no evidence of moisture at all. Even after 9 months of use topping off a 6.8-litre tank, there is no change of colour in the indicator beads that I sprinkle at each end. I no longer use the large Tuxing filter because I consider it a waste of air. I now only use the OEM and after-market black one. I agree that the carbon and silica media is not necessary and if I was using one of these I would only use the molecular sieve. @ airgunfans. The problem with your hypothesis is 1 there is insufficient space between the two tubes to allow enough expansion for the plastic tube to explode and 2 if the inlet line had sufficient pressure to have the reaction that you allude to, it would have been impossible to uncouple the QD connections. Sorry about the nitpicking guys but I believe these points are valid.

 

[airgunfans]

there is insufficient space between the two tubes to allow enough expansion for the plastic tube to explode ....

I don't know how big the gap nor how brittle the plastic is but the OP mentioned that "... saw that active charcoals closest to the Yong Heng pump end were compressed and caked up towards the opening...."

This is a strong proof that an explosion had occurred. Had it been an implosion, the charcoal should have been pushed away from the opening. 

edit : from the video, the gap between the cartridge and the inner wall surface of the aluminium tube can be seen to be actually quite big, somewhere around 5 mm I would say. Expanding the cartridge tube by such an amount can definitely crack it : 

 

[leeboysf]

Not much of an update, but I went ahead and got this oil-water separator (rose gold one). I know it’s an overkill, but I plan to purchase and fill medium size bottle with this setup in the near future. 

I still need to source the molecular sieve and cotton filter for the gold filter. I plan to put molecular sieve directly into the gold filter. 

 

[cosmic]

Open bleed valves BEFORE shutting off the compressor..

 

[Humdinger]

Leeboysf, instead of paying for desiccant and cotton separately you are better off just spending $20 for a replacement cartridge containing tan desiccant beads only. With photographic evidence to back your claim I would expect the vendor to send you a free replacement cartridge as a good will gesture. With your new water separator and care in bleeding your hoses of air after each fill you will not have a repeat of the previous failure. Damp charcoal and incomplete pressure release procedure were the causes of this rare failure. 

 

[leeboysf]

Leeboysf, instead of paying for desiccant and cotton separately you are better off just spending $20 for a replacement cartridge containing tan desiccant beads only. With photographic evidence to back your claim I would expect the vendor to send you a free replacement cartridge as a good will gesture. With your new water separator and care in bleeding your hoses of air after each fill you will not have a repeat of the previous failure. Damp charcoal and incomplete pressure release procedure were the causes of this rare failure. 

I emailed Tuxing seller/distributor from Amazon (I bought it from Amazon), but I didn’t hear back from them. BUT, Tuxing representative saw this thread and reached out to me via PM. I am quite impressed by Tuxing’s response so far. Hopefully, I get this all sorted out soon. 

 

[airgunfans]

Tuxing representative saw this thread and reached out to me via PM.

That's quite rare for Chinese ..... They usually enhance the products silently and quickly when poops happen. It seems that they are also advancing in customer service 

 

[Humdinger]

@Leeboysf, @Airgunfans, I re-read the posts in this thread and notice a critical connection error. The Tuxing filter cartridge is directional, and Leeboysf connected the filter housing and cartridge in reverse. The cartridge works properly with the green cartirdige seal o-rings on the input side so that moist air is forced first through the desiccant and then through the carbon to remove odors. Connected in reverse moist air dampened the carbon and blocked the opening. The error was compounded because it was connected to a rifle so there was no hose bleed as there is on a tank. Airgunfans directional diagrams shows Leeboysf's setup but it is not the direction air should flow. Whether it imploded or exploded, the cartridge was not designed to have moist air entering the output side. Leeboysf and all purchasers of this filter need to be aware and use the filter correctly. Tuxing should emphasize this in their setup instructions.

 

[airgunfans]

@Leeboysf, @Airgunfans, I re-read the posts in this thread and notice a critical connection error. The Tuxing filter cartridge is directional, and Leeboysf connected the filter housing and cartridge in reverse. The cartridge works properly with the green cartirdige seal o-rings on the input side so that moist air is forced first through the desiccant and then through the carbon to remove odors. Connected in reverse moist air dampened the carbon and blocked the opening. The error was compounded because it was connected to a rifle so there was no hose bleed as there is on a tank. Airgunfans directional diagrams shows Leeboysf's setup but it is not the direction air should flow. Whether it imploded or exploded, the cartridge was not designed to have moist air entering the output side. Leeboysf and all purchasers of this filter need to be aware and use the filter correctly. Tuxing should emphasize this in their setup instructions.

So Tuxing's youtube video is giving wrong info ? 

 

[Humdinger]

 Absolutely, the video is incorrect. It doesn't matter which direction if you are using desiccant only, but the correct orientation is to connect the male foster to the side of the filter with the cutout for the pressure seal o-rings and the output hose on the side of the filter where the black gasket fits into the cap. Check out any combination filter from any dive compressor that includes a filter and the air path is through the o-ring sealed end and desiccant first. The pressure equalizes regardles of air flow direction, but the unfiltered air should get dried before it enters the activated carbon section. Connecting the filter backwards combined with an incomplete pressure bleed caused the carbon to cake up and block the air inside. I agree with Airgunfans that when the air escaped towards the input side it exploded. Had Leeboysf connected it as I originally assumed he had, the air would have escaped first from the center of the cartridge and the trapped outer pressure would have imploded the cartridge if it had saturated carbon. It wouldn't have though because in the correct orientation, the air would be dry when it reached the carbon.

Two errors combined to cause the failure. Backwards hookup of the cartridge combined with an incomplete air pressure bleed on the input side. If the air flow was reversed moist air would have not reached the carbon first to clump it and block the air from escaping. If the pressure had been allowed to escape completely before disconnecting it would have not exploded either but it still would have ruined the cartridge.

Chinese instructions aren't infallible. These are the same people who advise using #46 hyrdraulic fluid to lubricate Yong Heng compressors, which is a no no.

 

[Eaglebeak]

Absolutely, the video is incorrect. It doesn't matter which direction if you are using desiccant only, but the correct orientation is to connect the male foster to the side of the filter with the cutout for the pressure seal o-rings and the output hose on the side of the filter where the black gasket fits into the cap. Check out any combination filter from any dive compressor that includes a filter and the air path is through the o-ring sealed end and desiccant first. The pressure equalizes regardles of air flow direction, but the unfiltered air should get dried before it enters the activated carbon section. Connecting the filter backwards combined with an incomplete pressure bleed caused the carbon to cake up and block the air inside. I agree with Airgunfans that when the air escaped towards the input side it exploded. Had Leeboysf connected it as I originally assumed he had, the air would have escaped first from the center of the cartridge and the trapped outer pressure would have imploded the cartridge if it had saturated carbon. It wouldn't have though because in the correct orientation, the air would be dry when it reached the carbon.

Two errors combined to cause the failure. Backwards hookup of the cartridge combined with an incomplete air pressure bleed on the input side. If the air flow was reversed moist air would have not reached the carbon first to clump it and block the air from escaping. If the pressure had been allowed to escape completely before disconnecting it would have not exploded either but it still would have ruined the cartridge.

Chinese instructions aren't infallible. These are the same people who advise using #46 hyrdraulic fluid to lubricate Yong Heng compressors, which is a no no.

I'm sorry Humdinger but I have to disagree with your assertion that the orientation of the filter cartridge was wrong and partly the cause of the failure. Have a look at how the Bauer filter is stacked and which end of the cartridge is sealed. The only difference between the two methods is that the Bauer unit has the inlet and outlet at the same end but the inlet air has to travel through the cavity before entering the cartridge at the opposite end and passing through the charcoal and then the desiccant last and exiting via the sealed section, the same way as the OPs and the same way that the Tuxing is configured from the supplier. I'm sure that the makers of these things have some idea about what direction they should be configured. Perhaps an arrow on the cartridge would alleviate any confusion. Your insistence that moisture and bleed procedure was the main cause of the failure doesn't stack up for the simple point that I have already stated, that the OP claimed that both the compressor and filter were both brand new with less than five minutes of run-time on them. I don't accept such short use could cause any moisture issues. I also can't see any problem with bleeding the system with the compressor bleed screw, everybody using one of these to fill a gun directly does it and there have been no other reports of this occurring. The fact that it happened just after decoupling is IMO just coincidence as if there was any pressure left in the line, it would not have been possible to decouple the fittings. I'm still of the belief that a loose piece of media has found its way into one of the internal passages causing a vacuum after the line was bled and perhaps taking a few seconds before the inner wall either collapsed or as airgunfans suggested, exploded. I'm not claiming that my hypothesis is correct, it is just the only conclusion that I can come to with the information supplied. 

 

[Humdinger]

Eaglebeak, I respect the points you make. However, the Bauer Triplex filter cartridge is more complex than a Tuxing cartridge. In the Bauer diagram incoming air travels around the outside of the Triplex but enters at the base at the sealed o-ring end. The diagram states that in the Triplex air is: A. Dried by dessicant B. Neutralized by carbon C: Micro Filtered to remove any particles. If Tuxing expects their cartridges to function properly incoming air needs to be dried first. With the way the 3 segments are arranged air must pass through the o-ring sealed end in order to be dried first. If they intend for air to enter the unsealed end of the cartridge first then the silica, desiccant, and carbon should be arranged in reverse order from how they are now.

I agree that two brief runs to a rifle shouldn't plug the cartridge. We can only speculate why it failed, but small Chinese compressors spew out more moisture than other types with larger water separator towers. Regardless of what happened to cause this failure, a cartridge should have incoming air pass through desiccant before carbon.. It really doesn't matter which housing side is input or output first since the pressure is equalized both ways. What does matter is the direction of unfiltered air through media in the 3 segment cartridges. Bauer's Triplex dries the air before it is deodorized.

In PCP fill tanks most users are better served using a desiccant only cartridge. That makes the input-output direction a moot point. If someone owns a compressor that has an oil smellf oil it helps to use multi element cartridges mounted so air drying is the first step regardless of what direction the air flow is in Tuxing videos.

 

[Eaglebeak]

@ Humdinger. Agreed that for airgun use, only the MS desiccant is necessary. The activated carbon and what I assume is hopcalite carulite catalyst or something similar is the third filler, which is used last to remove carbon monoxide, is only required for breathing quality air. If I was looking for that sort of purity I would not be relying on one of these filters to do the job. I am intrigued about the failure of this particular example and only interested in what caused it. It goes without saying that the Chinese have copied someone else's design after identifying a gap in the market to fill in the airgun world and sometimes they get things a little wrong especially with instruction translations. My intention is only to point out the holes in some of the theories that have been put forward so far. It is not my intention to have a debate on the correct or incorrect position and direction of the filling media. I'm sure that plenty of other people are using these things in the exact same way as the OP. It remains to be seen if it occurs again or if it's just a one-off faulty part or assembly issue. If so, it will probably remain a mystery.