Does everyone really need a extra filter system on their PCP compressor?

[Saltlake58]

Healthservices. All True. I guess I'm having trouble due to observation (3 years, no water in the tank), and more than that, I question the efficiency of the desiccant itself. Several years ago when the Yong Hengs first came out, there were extensive discussions about drying the air before it goes into the tank. The "Molecular" sieve was a hot topic, with one poster claimed that unless you actually know how to pack the molecular sieve correctly, doesn't matter as air and water will simply bypass the desiccant (molecular sieve) and happily go straight into the tank.

Perhaps, I'll take my filter and fill it, pack it tight with desiccant beads that change color when wet, and see if they ever change color. That combined with filling my guppy tank, then immediately depressurizing and inspecting the tank might be the only true ways to determine what my risks are. Haven't done either yet, so while I can pontificate all day, until I run the experiment, there's no evidence to validate one way or another. It's all speculation.

By the way, my job (got in by accident so don't hold it against me). I'm an auditor. As they say in the profession, if it isn't written down, it didn't happen.

I've got some chrony work to do, so rather than refill the tank immediately, I'll depressurize and see if any water is in the tank. I believe humidity was in the 15 -20%% range the day i filled that tank. Since I followed normal procedures of bleeding every few minutes, the air should be "normal" for my operation. Might be a few days before I do it, but I'll let you know how it turns out. If there's no water in the tank, I may not do the desiccant bead experiment to see how long they last. And if simply packing the tube incorrectly compromises the desiccant, that experiment might not be valid anyway.

Good conversation here.

 

[Healthservices]

Saltlake, no problem. Often times the way i word things, it does not come out right and could be interpretated differently from what meant to say. Your system maybe perfectly fine. I maybe a little on the cautious side. I really dont think much water will come out in your case but it is possible some water mist may first come out and that is it. And if some water did get into the system. I do not believe it is good for our pcps. We hardly ever fully discharge the air out and when we do we don't dischargeit with the intent to blow out the water. If there is water in there will it collect or will it be absorbed in the next charged of dry air or because we are using the same faulty system of charging we collect more water? I dunno that answer. Anyways it is a good conversation and makes one's mind think. Thats is a good thing. 



Allen

 

[Franklink]

I can 100% verify that water comes out, even when only filled on a low humidity day. Arizona here so I try to not fill my tanks unless humidity is 15% or less. 

My system is a Shoebox though, with a pancake compressor as the first stage. The blow out valve on the bottom of the pancake compressor always produces some moisture, even with low humidity. I also have one of the cheap little oil/water filters on the high pressure side, leaving the shoebox. I can usually squeeze a drop or two of water out of the cigarette/tampon filter right inside the inlet of the filter. I pack the rest of the filter with the little foam discs that come with them and none of that ever has water in it. 

As for tanks having dip tubes, I can verify that my 80 and 19cf scuba tanks came with dip tubes. I removed the one in the 19cf and have not ever gotten any moisture out of when tipped upside down. I've been meaning to completely empty the 80 the next time it gets low and do the same, just haven't gotten around to it yet. And for the SCBA tanks, I do not know if they have the drip tubes. Would be interested to know though since SCUBAs are meant to be dived with, but carbon fiber SCBAs aren't (I think). I think the dip tube purpose in the SCUBAs is to keep the poor diver from getting lungs full of nasty tank condensate if they ever invert while under water. 

 

[elwoodblues]

I have a solution if your compressor only draws air through the handle like the GX CS2 then do what I did I found fittings and a hose to feed the compressor ONLY pure as in 99.995 percent pure DRY Nitrogen has a dew point of -70 c and has less than .1 ppm moisture If thats all that goes in thats all that gets out. 120cf bottle cost 18 bucks for a fill(and if you remember to turn off when you finish its good for hundreds of fills) rent the tank for a month from local welding supply store about 10 bucks reg and fittings I had allready for tires and painting.

 

[Saltlake58]

Saltlake, no problem. Often times the way i word things, it does not come out right and could be interpretated differently from what meant to say. Your system maybe perfectly fine. I maybe a little on the cautious side. I really dont think much water will come out in your case but it is possible some water mist may first come out and that is it. And if some water did get into the system. I do not believe it is good for our pcps. We hardly ever fully discharge the air out and when we do we don't dischargeit with the intent to blow out the water. If there is water in there will it collect or will it be absorbed in the next charged of dry air or because we are using the same faulty system of charging we collect more water? I dunno that answer. Anyways it is a good conversation and makes one's mind think. Thats is a good thing. 



Allen

Not like I haven't said anything that's misunderstood as well. All good here.

These are all good discussions. I'm learning along the way and to me, unless something is totally out in left field, all opinions have value. Must admit, I'm just baffled by the math. Maybe someday I'll understand. In the meantime, I'll get my chrony work done and hopefully be able to empty the tank later this week. That'll at least tell me if my babblings are correct or need a bit more research.

As for more water collecting each time you fill, I'm inclined to believe it's cumulative. Each time I fill, I should get more water in the tank. My hope is that the amounts are so insignificant due to bleeding the compressor frequently, I don't need to worry about it. And, I will vouch, I get water every time I bleed the compressor. So, the question becomes, how much gets past the compressor into the bottle. We shall see, I hope later this week. Frankly, I don't know which direction it'll go. It'll be interesting.

 

[Saltlake58]

I can 100% verify that water comes out, even when only filled on a low humidity day. Arizona here so I try to not fill my tanks unless humidity is 15% or less. 

My system is a Shoebox though, with a pancake compressor as the first stage. The blow out valve on the bottom of the pancake compressor always produces some moisture, even with low humidity. I also have one of the cheap little oil/water filters on the high pressure side, leaving the shoebox. I can usually squeeze a drop or two of water out of the cigarette/tampon filter right inside the inlet of the filter. I pack the rest of the filter with the little foam discs that come with them and none of that ever has water in it. 

As for tanks having dip tubes, I can verify that my 80 and 19cf scuba tanks came with dip tubes. I removed the one in the 19cf and have not ever gotten any moisture out of when tipped upside down. I've been meaning to completely empty the 80 the next time it gets low and do the same, just haven't gotten around to it yet. And for the SCBA tanks, I do not know if they have the drip tubes. Would be interested to know though since SCUBAs are meant to be dived with, but carbon fiber SCBAs aren't (I think). I think the dip tube purpose in the SCUBAs is to keep the poor diver from getting lungs full of nasty tank condensate if they ever invert while under water.

Yes, there is water. When I bleed the compressor, it spits all over the place. The YH compressors have a space where water collects and is bled off. Hoping that I empty that little spot frequently enough to deal with the problem. The compressors also have another spot where oil collects, you blow that out as well and it keeps most of the nasties out of the tank.

 

[Saltlake58]

I have a solution if your compressor only draws air through the handle like the GX CS2 then do what I did I found fittings and a hose to feed the compressor ONLY pure as in 99.995 percent pure DRY Nitrogen has a dew point of -70 c and has less than .1 ppm moisture If thats all that goes in thats all that gets out. 120cf bottle cost 18 bucks for a fill(and if you remember to turn off when you finish its good for hundreds of fills) rent the tank for a month from local welding supply store about 10 bucks reg and fittings I had allready for tires and painting.

Not sure I understand. You bought a GX CS2, and connected it to a Nitrogen bottle. When you run the GX, it pulls only Nitrogen from the bottle? Is that correct? If so, what pressure is the nitrogen bottle at? Could you fill directly from the nitrogen bottle, or do you need the compressor to get the gas to the correct pressure?

Interesting . . . . . . . . .

 

[LMNOP]

A properly designed compressor does not require additional Rube Goldberg inventions regardless of how clever they may actually be to make up for the lack of properly engineered initial filtration. If you see a cloud puff out your PCP when you shoot it there is moisture in the system.

 

[Saltlake58]

I'll agree that a well designed compressor doesn't need all the fancy rube Goldberg stuff. However, we are talking the cheapest compressor on the market. Is it well designed? I don't know. Seems to be (design and execution are two different things). But, since no definitive studies are complete that I can find, all we have are our opinions. And as I say, mine is worth what you pay for it.

Also on the cloud puff out of your PC, let me offer another possible source. If it's a humid day, and you see a condensation cloud, it might be due to cold air from your gun (expanding air cools rapidly) causing the moisture in the air to condense. That I have seen. So, could be either.

 

[LMNOP]

Also on the cloud puff out of your PC, let me offer another possible source. If it's a humid day, and you see a condensation cloud, it might be due to cold air from your gun (expanding air cools rapidly) causing the moisture in the air to condense. That I have seen. So, could be either.

I am in Alabama and it was so humid yesterday that my scope and rifle were soaking wet and dripping water from condensation during plinking after moving out of the 76F AC cooled house. In the 30 rounds I fired from my Concept Lite I never saw a cloud. I am not saying you are wrong just that it may vary on location or elevation. The only time I have seen the cloud puff is when there has been moisture incursion into the system (not mine, but my fathers which puffed clouds and was confirmed by AoA to be “full of water”)

I have owned a LC-110 since 2018 that I use to fill my 90 cu-in bottle. I fill inside and the humidity is relative 50-55%. I have no bolt-on extras other than stock. I have never experienced indicators of moisture incursion into my air systems. 

Like many experiences we all share I suspect much of it may vary based on location and circumstances. I applaud the innovation and inventions constructed by our AGD friends to work around improper engineering but like you I think at a certain point indeed you get what you pay for. The somewhat inexpensive portable compressors we see under various brands are certainly suspect and are often water pumps as much as they are air compressors.

 

[Saltlake58]

LMNOP - agreed. So many variables are at play it can be very difficult to isolate the right variables to fix a problem. Discussion is good, as it brings forth different opinions and gives a chance to test. This is all good stuff. 

And when all is said and done, we'll all walk away with out own opinions, and our own versions of the secret sauce that make shooting fun for each of us.

I will ask though, If you fill in 50% relative humidity, and have no incursion problems, are you using a Yong Heng style or something with a tad different design. If YH, (ok, even if not a yong heng) what's the procedure you go through? how often do you bleed and such?

many thanks, always want to learn from others experience in tougher climates than I live in. 

By the way, my wife is from Mississippi. We go out to visit once in a while. This desert boy was raised in alpine forests (moved to Salt Lake later in life). The climate in the South is just hard for me. Makes everything green, but wow, that humidity takes a toll.

 

[LMNOP]

Saltlake58 - 100% agree with you and I love respectful conversation with our fellow AGD friends. SLC is a wonderful area and I have been there many times. I am always dumbfounded by a cold beverage glass being perfectly dry whereas here it is just dripping water.

Here is my setup, I fill in the basement, and as of now:

Bottle fills my Brocock Concept Lite.

 

[LMNOP]

Procedure: 2 minute warm up, about a 3 minute top off from 200 bar to 310 bar, bleed, disconnect, and 2 minute cool down with bleed valve open.

I have 12 hours and 30 minutes on my 2018 Daystate LC-110 (Coltri MCH-3 LC EM) which is around 150 bottle top-offs.

 

[elwoodblues]

The nitrogen bottle is at around 2200 psi no where near fill pressure for guns. I feed about 6-10 psi into the inlet on the compressor that then gets gun to desired pressure with NO MOISTURE. I can watch the needle on the nitrogen regulator delivery gauge bounce slighty while working. works great You cant get anything dryer than Nitrogen to fill your system.

I was going to get a 6K n2 bottle but buy the time buy a 4500 psi delivery pressure regulator, micro bore hose, fittings etc I'd have been into it 7-8 hundred bucks and thats with me getting extra discounts as I worked in the compressed gas /welding supply industry for 50 years just retired a year ago. Then I'd have the joy of moving a 600lb 6k N2 bottle into my small shop space, yes a 6k 502 cuft tank weighs almost 600 lbs So at this point the 300 dollar GX cs2/3 compressor is a great deal even if I have to buy a new one every 2-3 years

BTW I've filled my Maurader 6 times and my Avenger 4 Times in the last month total pump time 37 minutes, moisture amount zero . ;>)

 

[Saltlake58]

LMNOP - love the setup. Nice compressor, just out of my price range. I believe you are right. A well designed compressor should take care of the condensation without all the extras. As for humidity, it's been the monsoon season for us. Two (yes, TWO) major thunder storms with driving rain this week. Granted that's the first rain in 2 months. But the storms took us from driest year on record to third driest. For the most part, the cold beverage glasses would be dry as a bone here.

I'll keep you posted on what I find when I open the guppy bottle later this week.

 

[Saltlake58]

The nitrogen bottle is at around 2200 psi no where near fill pressure for guns. I feed about 6-10 psi into the inlet on the compressor that then gets gun to desired pressure with NO MOISTURE. I can watch the needle on the nitrogen regulator delivery gauge bounce slighty while working. works great You cant get anything dryer than Nitrogen to fill your system.

I was going to get a 6K n2 bottle but buy the time buy a 4500 psi delivery pressure regulator, micro bore hose, fittings etc I'd have been into it 7-8 hundred bucks and thats with me getting extra discounts as I worked in the compressed gas /welding supply industry for 50 years just retired a year ago. Then I'd have the joy of moving a 600lb 6k N2 bottle into my small shop space, yes a 6k 502 cuft tank weighs almost 600 lbs So at this point the 300 dollar GX cs2/3 compressor is a great deal even if I have to buy a new one every 2-3 years

BTW I've filled my Maurader 6 times and my Avenger 4 Times in the last month total pump time 37 minutes, moisture amount zero . ;>)

Elwoodblues - you have space, and more importantly, knowledge of things welding / gas supply. Those are things I lack in this arena. Ingenuity at its best! Keep it up and maybe we can find a way to get N2 to the average shooter. Love this stuff!

 

[Saltlake58]

and referring to my screwed up math above, did I get the conversion wrong or what? 74cf tank translates to a 6.8 liter tank. There's the first mistake in the math, the conversion. Considering I had it at over 2000 liters, that makes a huge difference. So, at 4ml per liter compressed air, that's less than 28 ml per fill from zero and the bleed process takes care of most of that. Oh well, math was never my strong point.

 

[oldsparky]

A few years ago I had an Omega Turbo Charger compressor. The dealer told me the air would be dry enough. I live in the desert in Arizona and the compressor lived in a climate controlled room. Out of curiosity I brought home test equipment from our lab. The compressed air was regulated down to 3000 psi for the test equipment the ambient was 72F humidity we 20%.. My omega put out air that measured 119.3 PPMV moisture. Using a Omega in line filter the moisture went down to 24 PPMV. I also tested air purchased from AOA it was 20 PPMV. In my opinion my air was to wet as it was without a filter. Before testing I contacted Styer and Daystate and they both told me diving air standards which was about the 24 PPMV from what I found. I now have a Alkin that has a separator and a filter. I haven't tested it. I should for kicks.

 

[Saltlake58]

Old Sparky - I assume PPM is parts per million / volume or something like that, am I close?

I don't believe we will ever have perfectly dry air, unless of course you go with something produced in a factory like Nitrogen, that gets pretty close.

Then again, 24 ppmv seems (if I got the calculation right) pretty close as well. That's .00024% humidity. I'd say that's pretty dry.

Now, on to the experiment!

I promised to blow down my guppy tank and do a visual inspection. I did so tonight. Finally did enough chrony work to get the pressure down below my gun fill pressure, so emptied the tank, took the valve out and brought it in to inspect.

Started with a bore scope. dropped it into the tank and no sigh of water at all. Next, just to make sure the camera didn't lie, I turned it upside down and tried to shake out any water onto my hand. Nothing.

While I don't have any fancy equipment, I can say that after 3 years of filling with nothing but the Yong Heng filter and the black filter with one of the filter elements, 2 inches of charcoal, and 2 inches of desiccant beads (that I never changed in 3 years, so they couldn't be doing anything), there was no moisture in the tank. That's the first time I've had that valve off in 3 years. The filter is like this one,Oil-Water Separator Air Filters High Pressure PCP Compressor Pump 4500psi/30Mpa | eBay

I threw the charcoal and beads out tonight. Replaced with the absorber filters.

By the way, I learned a trick for removing valves.  In this case the part that screws into the tank is brass, the tank threads are aluminum. If you blow down the tank, of course it gets cold. The brass seems to shrink faster than the aluminum (or maybe it's the O-Ring, I don't know), making it easier to take the valve off. I was able to remove it with hand strength and no wrenches.

I think all this means for me is that personally I'll skip the extra air drying equipment and stick pretty much to the basics. The YH filter and the black one filled with absorbers seems to be enough. Bleed frequently (every 3 to 5 minutes in my case, and just keep an eye on the whole rig. Have fun Ya All!

 

[Jungle_George]

Here is the math I came up with: (Please bear with the mixed imperial and metric units, it works out in the end)

100% relative humidity at 70F has a water concentration of 19.5 grams per cubic meter (I found that on the internet so it must be true)

A 30 minute SCBA tank compressed has 45 cubic feet

There are 35.31 cubic feet in a cubic meter

So there is 1.27 cubic meters in a 30 minute SCBA

At 100% relative humidity there is 1.27 X 19.5 = 24.765 grams of water

At 8% relative humidity: 24.765 X 0.08 = 1.981 grams (since water generally has a density of 1, grams and ml would be the same)

So basically there is about 2 milliliters of water that potentially could get in the bottle. 

I have no idea how efficient the oil/water separator is on a Yong Heng so let's guess 50%, that leaves 1 ml that gets into the bottle without anything beyond the separator.

The question then becomes, does any of that remaining water condense in the tank or gun to an extent that matters?