N/A Moisture in PCP airguns

[3Crows]

How many pcp owners go to all this extreme to keep Moisture out ?

I stress over it and use the large gold filter and an inline “ cigarette “ filter.

I’ll bet many, many pcp owners don’t give to much more thought to this. So I’ll ask again …. Have there been any incidents of heavy moisture in the airguns tank that caused a failure of any sort ??

I bought a used but beautiful on the outside M-Rod Gen .25 and after a few months it began leaking. I found severe corrosion in the area of the gauge block. I was able to source a new tube and had AGR cut it for a hybrid aluminum and steel so it all turned out well at a few extra $. But, yes, water in the guns can ruin them.

The YH compressor is best userd for pumping to a bottle. The CSX is best used for pumping direct to the rifle.

Some dive shops can fill to 4500 psi or close enough though scuba tanks are generally anywhere from 2100 to 3500 (rounding off) with 3000 psi being the most common and HP steels being 3450.

 

[nervoustrig]

I bought a used but beautiful on the outside M-Rod Gen .25 and after a few months it began leaking. I found severe corrosion in the area of the gauge block.

Do you happen to recall whether the corrosion was outside of the O-rings or between them?

 

[coastal drifter]

I bought a used but beautiful on the outside M-Rod Gen .25 and after a few months it began leaking. I found severe corrosion in the area of the gauge block. I was able to source a new tube and had AGR cut it for a hybrid aluminum and steel so it all turned out well at a few extra $. But, yes, water in the guns can ruin them.

The YH compressor is best userd for pumping to a bottle. The CSX is best used for pumping direct to the rifle.

Some dive shops can fill to 4500 psi or close enough though scuba tanks are generally anywhere from 2100 to 3500 (rounding off) with 3000 psi being the most common and HP steels being 3450.

Most dive shops in my area wont fill above 3200psi and know nothing about PCPs. I did find one years ago but the since close somewhat forcing me to find an alternative source. I live in probably the dive capital of the US.

 

[3Crows]

Most dive shops in my area wont fill above 3200psi and know nothing about PCPs. I did find one years ago but the since close somewhat forcing me to find an alternative source. I live in probably the dive capital of the US.

Yes, but the shop I most recently moonlighted at could and would as long as the cylinder is in hydro or certification life, has a current annual VIP and is a DOT cylinder. The problem(s) gets into the VIP and inspection standards applied to scba and PCP tanks for what is an industry practice for scuba (the VIP) and they often have no idea of what to inspect for those cylinders. So they will not.

We kept our bank around 5000 psi I recall. I could fill several large scuba tanks before the compressor would kick in. We had a membrane for Nitrox.

 

[3Crows]

Do you happen to recall whether the corrosion was outside of the O-rings or between them?

Both outside and between. Let me be clear, the corrosion that ended the life of the tube was just forward of and coincident with the O-ring on the HP side of the gage block. The corrosion finally undermined the sealing surface to the tube and it began to leak. I had some success with a hone to get a seal but there was enough pitting that it would eventually leak again. I guess as the O-ring became compressed.

 

[coastal drifter]

Yes, but the shop I most recently moonlighted at could and would as long as the cylinder is in hydro or certification life, has a current annual VIP and is a DOT cylinder. The problem(s) gets into the VIP and inspection standards applied to scba and PCP tanks for what is an industry practice for scuba (the VIP) and they often have no idea of what to inspect for those cylinders. So they will not.

We kept our bank around 5000 psi I recall. I could fill several large scuba tanks before the compressor would kick in. We had a membrane for Nitrox.

yep ,mine is a luxfer carbon fiber bottle with hydro dates but still cant find a dive shop withing 30 miles that will fill above 3400. Fire departments if you know some one will. I just bought a high pressure breathable air compressor (Alkin w31 mariner) to solve my issue. Most HPA compressors are re-branded Chinese compressors marked up for max profit. Even the more expensive models seem to not last too long.

 

[coastal drifter]

Yes, but the shop I most recently moonlighted at could and would as long as the cylinder is in hydro or certification life, has a current annual VIP and is a DOT cylinder. The problem(s) gets into the VIP and inspection standards applied to scba and PCP tanks for what is an industry practice for scuba (the VIP) and they often have no idea of what to inspect for those cylinders. So they will not.

We kept our bank around 5000 psi I recall. I could fill several large scuba tanks before the compressor would kick in. We had a membrane for Nitrox.

can I ask where you moonlight as I'm not aware of a lot of scuba in KS

 

[Ricklin]

Professionally prior to retirement last year I sold serviced and supplied large dental equipment. Dental drills (mostly) run on compressed air. Wet air is a big issue, both for hygiene (water is life) and miniature dental turbines spinning at up to one half million RPM. A little water is a big issue. A dental compressed air system supplies my home air pressure needs, the beauty being air dried to a -150 degree dew point, and 5 micron filtration feeds El Cheapo my Yong Heng knock off regulated down to 5-10 PSI at the pump inlet. I have the big gold filter and use it, I could likely eliminate it. Checked it after a bottle fill and several refills, like new inside zero evidence of moisture. No evidence of any moisture when bleeding down, none. Extra filtration never hurts justs wastes a little more air when bleeding down for disconnect. Hope I am not boring you all to death with El Cheapo as I'm uncertain how my setup could be duplicated inexpensively, like high end scuba compressors, the price of a dental air system will get your attention. In my experience desiccant dried air is superior to refrigerated dryer systems, a measure of that is the dewpoint of the compressed air product. I am a fan of desiccant type air drying systems, based on decades of experience where dry air really does matter. Desiccant drying is done just post compression prior to the storage tank hot wet air flows through a large tube of Silica gel, a secondary tank back flushes the desiccant stack with each pump up cycle. A similar system could be duplicated inexpensively to add on to a shop compressor.

 

[Normkel]

Any valves used for a life support system, scba or scuba, are going to have a dip tube. This tube usually screws in but is sometimes pressed in.



Inverting a tank equipped with such a valve will not vent water out. I do not know if purpose made paint ball or PCP cylinders and valves are so equipped but I suspect they are if for no reason but to prevent FOD from clogging the valve, the air lines or your gun.

We have cut the tube, flush with the fitting to allow any water to be expelled by inverting the tank. That said, I have not detected any water or signs of water in any of you bottles or SCBA tanks used for air gunning.

 

[Normkel]

I bought a used but beautiful on the outside M-Rod Gen .25 and after a few months it began leaking. I found severe corrosion in the area of the gauge block. I was able to source a new tube and had AGR cut it for a hybrid aluminum and steel so it all turned out well at a few extra $. But, yes, water in the guns can ruin them.

The YH compressor is best userd for pumping to a bottle. The CSX is best used for pumping direct to the rifle.

Some dive shops can fill to 4500 psi or close enough though scuba tanks are generally anywhere from 2100 to 3500 (rounding off) with 3000 psi being the most common and HP steels being 3450.

Is the scuba filling typically the same drill as we used, years ago? We filled tanks from a manifold, connecting multiple tanks, that were immersed in cooling water. That was the main reason we only filled to 2200 PSI. Maybe that's why shops typically only fill to that maximum?

 

[corny]

Even 1% relative humidity at atmospheric pressure will result us 100% humidity at 3000 psi.

If you wants dry air, you need a water trap and a dryer on your compressor

 

[HogKiller]

I keep my airguns and compressor in the basement with climate control, RH usually around 45~50% year around.

How do you use silicone oil on every fill? just drip a few drops into quick connect before running the compressor?

Do you have a molecular sieve in the filter loop? OR even two of them, I have one as the 3rd filter, my first filter appears to catch 90+% of the moisture, the second catches the balance, the Sieve is for paranoia.

 

[elwoodblues]

If you want DRI air then feed your compressor nothing but pure Nitrogen, nothing else compares .

 

[bchannell]

There are just so many specifics that go into each person's setup for filling their guns, that it's hard to diagnose. I would simply say, that IF I lived in an area of high relative humidity, such as the southern states, then I would do one of two things. A) look into pumping nitrogen, or B) look into a serious, and I don't mean some tiny cotton filter, but a serious moisture filtration system. Having worked in the chemical industry most of my life and being an HVAC business owner/technician, I can tell you that cartridge filters for removing moisture from air, that you can buy online easily, work only marginally at best. Not saying don't use them, I'm saying upkeep is extensive, been there. To give you some idea, we used what are called "zero air generators" for dry air.

 

[corny]

There are just so many specifics that go into each person's setup for filling their guns, that it's hard to diagnose. I would simply say, that IF I lived in an area of high relative humidity, such as the southern states, then I would do one of two things. A) look into pumping nitrogen, or B) look into a serious, and I don't mean some tiny cotton filter, but a serious moisture filtration system. Having worked in the chemical industry most of my life and being an HVAC business owner/technician, I can tell you that cartridge filters for removing moisture from air, that you can buy online easily, work only marginally at best. Not saying don't use them, I'm saying upkeep is extensive, been there. To give you some idea, we used what are called "zero air generators" for dry air.

Running a high pressure compressor anywhere on this earth…will result in very very wet air.

You need to dry it

 

[BSJ]

There is much discussion of this topic in the Tanks, Pumps, Compressors forum.

 

[rokonman]

I had the I believe it’s called firing pot fall off of my AirArms S510 and start sliding around in the air tube. After years of filling direct from a Shoebox and later direct from a small tank that was filled directly from the same Shoebox without a filter anywhere in site in humid New England. I was really expecting to find corrosion or at least moisture in the tank. Nothing but a shiny dry tube and clean shiny parts. Perhaps we overthink this stuff and should just enjoy our guns and deal with the problem if it ever rears it head?

 

[coastal drifter]

Running a high pressure compressor anywhere on this earth…will result in very very wet air.

You need to dry it

don't even need to be high pressure, your average nail gun pan compressor (120PSI) max has a bleed valve which after running for the day on a job will have water in it.

 

[Normkel]

don't even need to be high pressure, your average nail gun pan compressor (120PSI) max has a bleed valve which after running for the day on a job will have water in it.

And that draining removes water demonstrates that compressing the air causes water to drop out of the air?

The question, seems to be what you posed: Since compressing air removes water from the air, is the remaining water an issue, and how should we respond?

In my case, I find no water signs in my guns, despite not adding desiccants, additional filters, etc, so it appears unwise to add the additional compexity and/or additional volume requiring pressurizing during each fill cycle.

 

[coastal drifter]

And that draining removes water demonstrates that compressing the air causes water to drop out of the air?

The question, seems to be what you posed: Since compressing air removes water from the air, is the remaining water an issue, and how should we respond?

In my case, I find no water signs in my guns, despite not adding desiccants, additional filters, etc, so it appears unwise to add the additional compexity and/or additional volume requiring pressurizing during each fill cycle.

so by that logic there is no reason compressor need filters to fill scuba tanks