moisture in the compressed air ?

[beerthief]

1. The ability of 'air' to carry water vapor depends mostly upon pressure and temperature, so an increase in pressure or drop in temperature can cause condensation. - The fact is that the air is hot going in, so it cools in the tanks, and that's the most significant and common event that leads to condensation inside the gun/tank.

maybe too much coffee thinking ? what if you cool the air before it enters your gun or tank ? an inline chiller . compressed air from your compression source enters a chiller (thnk a cooler full of ice water ). Then enters the water/ oil filter then fills the tank / gun ? would that cold air/ water vapor release the vapor into the filter medium before it enters the gun / tank ?
Like i said , maybe too much coffee ?

 

[rcs9250]

I don’t see why that wouldn’t work. To me, the issue is, how dry is the air with ?
I want to say, between scuba and airguns and maybe some other uses, molecular sieves are sort of the recognized best practice. Is that level of dryness necessary? Controversial. A couple of manufacturers I checked with prefer/specify scuba quality air but many folks do not do that level and seem to run OK. I do airgunning for fun/hobby. I don’t mind tearing one down, but if I can avoid it I will. That’s why I have an Alkin.
Getting back to your question. Basically what you are suggesting is what most compressors have between stages, an intercooler and or seperator. Air comes out of one stage, gets sent to a radiator or coiled tube with fins and then to a seperator to catch any moisture. They don’t usually use a water bath but that doesn’t mean it can’t be done. The skies the limit on inovation. With new methods of drying air, I always see testing the moisture level as being the stumbling block as it isn’t cheap. I am unaware of a definitive method of testing at home to get a legitimate value.
Let us know if you try something. There’s a lot of users that could benefit from a DIY method.
Often times, with low cfm compressors, one complaint is the additional volume that has to be filled to do that cooling step. That’s where a molecular sieve kinda shines but costs $$.

 

[drsquall]

It will always be an issue for PCPs. That's why I quit using those compressors to fill a gun directly no matter how many filters you have on it the risk is there for moisture fallout in the gun itself. I strictly fill from a SCBA now.

 

[Gerry52]

Wouldn't work! If you create more temperature differential between cooled air going in & warm air (in tank) that's been compressed it works (theoretically) to create MORE condensation. That's exactly why we have to remove as much moisture as possible in the air BEFORE being compressed. % of moisture in gas being compressed + pressurization (resulting in adiabatic heating) = CONDENSATION. It's not about temperature, it's percentage of moisture in gas to be compressed so cooling the air has no bearing. THE TEMPERATURE of air going in will STILL be heated to same temperature WITHIN tank.

 

[beerthief]

Wouldn't work! If you create more temperature differential between cooled air going in & warm air (in tank) that's been compressed it works (theoretically) to create MORE condensation. That's exactly why we have to remove as much moisture as possible in the air BEFORE being compressed. % of moisture in gas being compressed + pressurization (resulting in adiabatic heating) = CONDENSATION. It's not about temperature, it's percentage of moisture in gas to be compressed so cooling the air has no bearing. THE TEMPERATURE of air going in will STILL be heated to same temperature WITHIN tank.

yup i get it now . like i said too much coffee

 

[karl_h]

Wouldn't work! If you create more temperature differential between cooled air going in & warm air (in tank) that's been compressed it works (theoretically) to create MORE condensation. That's exactly why we have to remove as much moisture as possible in the air BEFORE being compressed. % of moisture in gas being compressed + pressurization (resulting in adiabatic heating) = CONDENSATION. It's not about temperature, it's percentage of moisture in gas to be compressed so cooling the air has no bearing. THE TEMPERATURE of air going in will STILL be heated to same temperature WITHIN tank.

You realistically will never get enough moisture out of the air pre-compressor to do any good. At roughly 68 degrees F, the air at humidity level of just below 0.7 percent and compressed to 300BAR without a molecular sieve is 100% humidity once the tank cools down to 68 degrees F. Cool down any more and condensation in tank. 200Bar is not much better, I'd have to look it up but the difference is less than a couple or three percent.

 

[beerthief]

You realistically will never get enough moisture out of the air pre-compressor to do any good. At roughly 68 degrees F, the air at humidity level of just below 0.7 percent and compressed to 300BAR without a molecular sieve is 100% humidity once the tank cools down to 68 degrees F. Cool down any more and condensation in tank. 200Bar is not much better, I'd have to look it up but the difference is less than a couple or three percent.

so what about nitrogen does that eliminate ALL moisture in the gun ?

 

[Gerry52]

You realistically will never get enough moisture out of the air pre-compressor to do any good. At roughly 68 degrees F, the air at humidity level of just below 0.7 percent and compressed to 300BAR without a molecular sieve is 100% humidity once the tank cools down to 68 degrees F. Cool down any more and condensation in tank. 200Bar is not much better, I'd have to look it up but the difference is less than a couple or three percent.

"You realistically will never get enough moisture out of the air pre-compressor to do any good." That statement simply NOT true. That's why BREATHING AIR compressors have moisture separators, because they DO work! If you truly believe that fill your gun without filtered air for a while & see the difference.

 

[karl_h]

Don't quote me, going by memory and I'm not going to look it up, the dewpoint of industrial nitrogen, like tanks you get for welding, is somewhere around negative 85-95 degrees Celsius. The dewpoint of air at 300 Bar and 100% humidity at 68 degrees F is just a hair under negative 40 degrees celsius. Yes, nitrogen tanks have way less moisture in it, so much less it could never be a problem.

 

[karl_h]

"You realistically will never get enough moisture out of the air pre-compressor to do any good." That is simply NOT true. That's why BREATHING AIR compressors have moisture separators, because they DO work!

Re-read, talking about taking moisture out of air PRE compressor, and besides, breathing air cannot be made with just moisture separators. A moisture separator is only taking out water that is condensed already. You need a molecular sieve after to take out water vapor after the seperator(s). Unless you call a molecular sieve a moisture separator, which it is not.

 

[Gerry52]

Re-read, talking about taking moisture out of air PRE compressor, and besides, breathing air cannot be made with just moisture separators. A moisture separator is only taking out water that is condensed already. You need a molecular sieve after to take out water vapor after the seperator(s). Unless you call a molecular sieve a moisture separator, which it is not.

Yeah, got it. PRE-compressed air. My bad.

 

[LMNOP]

I intentionally add moisture to my air rifles to maintain consistent humidity and to avoid any excessive changes in humidity. I keep my air guns sealed in a hermetically sealed vacuum chamber devoid of all moisture. I figure if the external portion of the air cylinder, much like the internal portion, as well as all o-rings such as the breach o-ring are never exposed to dangerous substances like water my rifle will last just as long as the people who do not consider the above.

 

[elwoodblues]

so what about nitrogen does that eliminate ALL moisture in the gun ?

it has NO moisture, no Oxidizers, no C02 that is the only thing I feed my compressors and guns when you see people post pics of there broken YH pump its almost always due to Detonation only take a split second it has a dew point of 0.01ppm at minus 70F it drier that dri

 

[beerthief]

tomorrow s the day i plan to go talk to my local supplier for Nitrogen .
planing on a Altros unit . use C02 to power it and nitrogen supply to gun

 

[elwoodblues]

You will be very happy with that decision and you dont need a big 6000psi tank just a standard nitrogen tank and find the cheapest flowgauge for delivery to the altros

 

[Scotty1]

tomorrow s the day i plan to go talk to my local supplier for Nitrogen .
planing on a Altros unit . use C02 to power it and nitrogen supply to gun

Can I ask, why power it with C02?

 

[beerthief]

Can I ask, why power it with C02?

i can get it easily cheap , and i have the tanks from homebrewing , but i'm leaning towards a home compressor .
this all depends on what the Nitro guy say's

 

[beerthief]

Also just found a possible source for Fireman breathing air fill here in Bowling Green ?

 

[Scotty1]

i can get it easily cheap , and i have the tanks from homebrewing , but i'm leaning towards a home compressor .
this all depends on what the Nitro guy say's

Here’s hoping for a reasonable price!

 

[BlackICE]

Assuming you don't have a siphon tube in your tank, wouldn't cooling your tank in a refrigerator and then purging some air get rid of any water that would be in liquid form at room temp?