What is adequate filtering for air drying?

[Beanflip]

How important are filters and what is adequate filtration? If I use a dry cotton filter each fill is that adequate? Are cotton filter dryers enough?

 

[Roamin Greco 1]

Great question. I'll be interested in the responses from the experienced PCP shooters, as well.

 

[FL22]

How important are filters and what is adequate filtration? If I use a dry cotton filter each fill is that adequate? Are cotton filter dryers enough?

I really don’t know, but I would like it if there was some sort of inline HPA moisture sensor/meter/alarm whatever device that would tell what is going on during a fill.

 

[Beanflip]

I really don’t know, but I would like it if there was some sort of inline HPA moisture sensor/meter/alarm whatever device that would tell what is going on during a fill.

Now that’s an interesting idea. I’d assume with the basic filters there may be almost always some level of moisture.

 

[FL22]

Now that’s an interesting idea. I’d assume with the basic filters there may be almost always some level of moisture.

I swap out my cotton pre filter after every 15 min run GX2.

 

[Beanflip]

I swap out my cotton pre filter after every 15 min run GX2.

Wow. I am usually filling directly to my gun in the ac of the house and in those normally less than 5 minutes the filter is damp.

 

[FL22]

Wow. I am usually filling directly to my gun in the ac of the house and in those normally less than 5 minutes the filter is damp.

My GX is on the floor (inside AC too) fill hose vertically connected to pre filter to vertical desiccant and post filter then fill my guns on my bench. I also have a hose connected to the blowoff venting to outside. To me it works A++

 

[FL22]

Here is my setup. Total of 3 cotton filters, one is cut in half perfect fit for use in the desiccant filter on each side.

 

[Gerry52]

I mainly use the cotton filters cut to 1/2" at each end of filter housing to hold in the silica bead dessicant I've replaced them with. The only one I truly use as a filter is in the small one that came with my Yong Heng (before my larger filter) & it gets air dried after every use. They have their place but I'd NEVER depend solely on cotton to remove all moisture.

 

[Beanflip]

I'm not under any illusion that I'm removing all moisture.

What I've not heard anywhere is what is adequate.
Will some moisture always be present?
Who has experienced actual moisture damage and what were the circumstances?

 

[FL22]

I'm not under any illusion that I'm removing all moisture.

What I've not heard anywhere is what is adequate.
Will some moisture always be present?
Who has experienced actual moisture damage and what were the circumstances?

Basically as I understand it (very rudimentary lol) you want the compressed air to have the same or less moisture content as the air feeding the compressor. If I’m wrong I’m wrong .

 

[hameditor]

This HAM post may be of interest. Warning Distressing Content! PCP airgun corrosion - this happens to your air rifle!

Over the course of 10 years or so of repairing Marauder air rifles at Archer Airguns, I would say that more than 90% of them were sent to us for leak repair the huge majority of them being caused by water-generated corrosion. Inevitably the cause was filling by hand pump with no desiccant or other moisture filter.

That's based on hundreds of guns over time.

 

[Roamin Greco 1]

There must be an economical way of supplying a pump's intake (whether hand pump or mechanical) with the driest air possible. That would protect the gun and the pump, right? For example, a large, clear intake chamber full of dessicant beads that could be monitored for color changes. Obviously, this would not work fir those who use a pump to fill their gun in the field, but for home use, it should help? Also using silicone oil in the fill port would coat the insides of the gun and prevent corrosion and protect internal seals, right?

 

[FL22]

There must be an economical way of supplying a pump's intake (whether hand pump or mechanical) with the driest air possible. That would protect the gun and the pump, right? For example, a large, clear intake chamber full of dessicant beads that could be monitored for color changes. Obviously, this would not work fir those who use a pump to fill their gun in the field, but for home use, it should help? Also using silicone oil in the fill port would coat the insides of the gun and prevent corrosion and protect internal seals, right?

I called this thread below the “event horizon” after I read it in it’s entirety I had a massive headache .

So if you are truly ready for one of the darkest rabbit holes (to me) in the PCP universe here you go.

Others Pre dryer

Jul 9, 2023

Most PCP users have some sort of high-pressure pump to refill their airguns and/or portable tanks. Most have some sort of device to trap or absorb moisture in the compressed air column. Higher end units might be equipped with high pressure post filters. The former ones are very inefficient, and require regular replacement of the (treated?) filter cartridge. The latter ones have two drawbacks. The filter cartridges are expensive (≈$20 each), and you can’t tell if they’re still being effective. Further, the extra volume they contain requires pressurizing before your airgun starts to refill...

• Alan
• Replies: 96
• Forum: Tanks, Pumps and Compressors

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[elwoodblues]

The Only way to insure no water or oxygen is to feed the compressor Nitrogen My supplier only sells grade 4.5 nitrogen that is their normal level that 99.995 % pure . Nitrogen is also the most abundant molecule in air 78.9 %
so the compressed gas companies make and need to sell lots of nitrogen to make more money on the other gases they make and sell Oxygen and the biggie Argon used in tons of industrial applications. That makes Nitrogen one of the least costly products they sell.

 

[Danman]

There must be an economical way of supplying a pump's intake (whether hand pump or mechanical) with the driest air possible. That would protect the gun and the pump, right? For example, a large, clear intake chamber full of dessicant beads that could be monitored for color changes. Obviously, this would not work fir those who use a pump to fill their gun in the field, but for home use, it should help? Also using silicone oil in the fill port would coat the insides of the gun and prevent corrosion and protect internal seals, right?

The Hill MK5 hand pump uses such a setup, it works....somewhat lol. Dessicant and color changing beads as a pre-filter, with no post-filter for the actual compressed air. For a year and a half I used it as such, filling my AA S510 weekly give or take in my climate controlled house ONLY with just the prefilter, and then later my Brk Ghost also. Replaced the beads/dessicant twice a year (both pcps are over 4k beads are $8) About a year in the pump outlet was spitting out water and had me extremely concerned. I now use a inline cotton filter as well. I can easily unthread it, dry it out or repl it. The best part is being able to see inside the chamber if any moisture is getting by. Without the filter I was just guessing. Silicone oil lubricates the internals of both my hand pump and my Hill compressor. I add a drop or two infrequently to my 2 pcps fill ports as well. Lastly keep your gun higher than your fill equipment so liquid water cant get in while filling. Anything you can do to prevent moisture is worth it. For reference my Hill compressor instructions say to repl the post filter media every 10 hours of use....I will definitely be switching it out sooner! Spending $30 a year to ensure dry air from my hand pump and compressor is well worth the $$!