Source for Hand Pump Dryer/Desiccant Filter?

[sr1sws]

New to PCPs and I'm using a Benjamin hand pump with my Discovery.

I saw in the video of the Benji pump teardown that the guy had a dryer cartridge on the pump intake.

I searched, but I must be doing something wrong as I can't find a reference for the part.

Can some kind soul clue me in?

Thanks!
Steve

[RatRacer]

Here: http://sunopticsusa.com/airgun/tools-and-shooting-accessories/high-pressure-hand-pump-desiccant-kit/

or, you can cobble one together from Harbor Freight with a water separator and buying some desiccant and 1/4 npt fittings.

[sr1sws]

Nice, thanks!

[RMM]

Or you can make one.      With this homemade filter I can regenerate the desiccant via microwave or oven which means I don't throw the typical airgun pump filter away. 

[Monkeydad1969]

Or you can make one.      With this homemade filter I can regenerate the desiccant via microwave or oven which means I don't throw the typical airgun pump filter away. 

Necessity is the mother of invention.  Do you have any pics with it connected to a pump?

Joe

[sr1sws]

Or you can make one.      With this homemade filter I can regenerate the desiccant via microwave or oven which means I don't throw the typical airgun pump filter away. 

I'm liking that.  Any source for the desiccant?

Steve

[sr1sws]

Get a bottle of compressed nitrogen doesn't have any water in it... just need a regulator..
I used that for pressurizing underground telephone cable.... or if you can find a used air dryer no I didn't say hair dryer
from the phone company. It will work just as good. Check with http://www.skycraftsurplus.com/storepictures.aspx
They have all kinds of weird stuff.

Ha... may give me a reason to drive to SkyCraft.  Haven't been there for years.  I live in Tampa

I'm thinking using scuba tanks would be cheaper (and safer?) than dealing with 6000psi nitrogen.

Steve

[RMM]

Or you can make one.      With this homemade filter I can regenerate the desiccant via microwave or oven which means I don't throw the typical airgun pump filter away. 


I'm liking that.  Any source for the desiccant?

http://www.silicagelpackets.com/    I used loose bulk, and 1lb fits nicely in a 1 pint jar. 

[RMM]

Or you can make one.      With this homemade filter I can regenerate the desiccant via microwave or oven which means I don't throw the typical airgun pump filter away. 



Necessity is the mother of invention.  Do you have any pics with it connected to a pump?

Joe

[Sandspike]

In this thread you will see a pic of my pump setup with a desiccant filter from HF and a hookup to boost it with 25psi from a compressor to make the pump 50% more efficient and cut pumping in half.
http://www.gatewaytoairguns.org/GTA/index.php?topic=62546.40

[RMM]

Here's a pic of the innards.



Parts list:

1:   One (1) Ball jar (type) and two lids.  Two lids were used for rigidity and the two (2) 7/16" holes were drilled with a Unibit.  A Unibit was used because a drill bit will tear and bend the lids.

2:   One (1) piece of 3/8" O.D. rigid tubing (I had some steel tubing laying around).  Cut the tubing to the length you desire for height out of the jar but long enough to keep it around 1/4" off the bottom of the jar.

2:   Two (2) 3/8" rubber grommets and two (2) rubber caps for hose barb and tubing

4:   Two (2) 1/8" MIP X 1/4" hose barbs, 1 for desiccant canister and 1 for pump.  (round off the barbs and the hose is easy to get on and off. 

5:   One (1) 1/8" MIP pipe coupling and some steel wool.  I used the pipe coupling to secure the hose barb and grommet to the jar lids.  The steel wool was stuffed into the pipe coupling for a filter to keep from sucking desiccant into the pump intake. 

5:   1/4" I.D. vinyl tubing.   The length determined by your needs.   

Of course the above is what I did with stuff I had laying around so use your imagination and work off my design.   

[Monkeydad1969]

Thanks for the pics, RMM.  Very cool.  I see that you have gone beyond a 'simple' pump, too.  Nice mechanical setup. 

Joe

[jkj61]

I was under the impression you get the moisture when you compress the air so does putting the filter on the intake really help?

[RMM]

I was under the impression you get the moisture when you compress the air so does putting the filter on the intake really help?

The moisture is in air, humidity, thus its removed before compression. 

Water can not be compressed.

[RMM]

Thanks for the pics, RMM.  Very cool.  I see that you have gone beyond a 'simple' pump, too.  Nice mechanical setup.

Thank you but I can not take credit for the pump setup as there was one before me and the accolades goes to him.   

Mine uses a 3/4 hp motor with a .67 hp input 40:1 gear reduction but I've learned a 50:1 or even better a 60:1 gearbox would slow the pumping cycle down considerably and give the pump time to cool between pump cycles.  This setup is not recommended for scuba tanks and mine can get quite warm filling 22 ci tanks using the Benjamin's required rest in between.

[Sandspike]

I was under the impression you get the moisture when you compress the air so does putting the filter on the intake really help?

       1st you need to understand Relative Humidity and how water vapor behaves. All air has some water vapor in it. (even the compressed air you buy) RH is the amount of water vapor in the air relative to the max it could hold at it's temperature and pressure. So 50% RH tells you the air contains half the amount it could hold. 100% is saturated air and it can't hold any more. When you take air and compress it to 100% the air will be at the Dew Point. DP is the point that water vapor will/must condense into liquid. Every cloud in the sky is at this point. So when it happens in a vessel like a tank....condensation must occur. Water always condenses on something. In the clouds it condenses on particles of dust, smoke and pollen.  In a tank...it condenses on the tank.
     Water vapor in air behaves a lot like liquid water in a sponge. When you take a sponge with the available spaces half full of water (50%) and squeeze (compress) the sponge till there are no empty spaces, the water will start coming out of the sponge.
 
        When you run air thru the compressor.....it is the first water removal for the air. Then when you take that air which has a lot less water in it and run it thru desiccant crystals, they remove even more of the water from that air.
       If the pump then takes that air and compresses it to the dew point more water will condense in the pump and when you depressurize the pump to remove it from the gun, you will see water exhausted from the pump. Using my boosting method I never see water come from my pump or see grey grease that has water in it. That tells me that the air I am moving into the gun is not at the dew point and therefore is very dry.
       Once air is in the gun and you lower the pressure by shooting the gun, the RH of the air in the gun will do nothing but go down with each shot as you depressurize the reservoir on the gun. So long as the RH is low enough that liquid water is not condensed on the metal, no corrosion can be formed.
       I hope this has not been too scientific for understanding. I've only been a scientist for over 40 years.
PS if you buy your air compressed already, and you believe that there is no water in that air you bought at the scuba shop or paint ball park or fire station, you are wrong. It's almost impossible to remove all the water from air. It's only dry enough to cause no condensation in your gun, that's all. 

[sr1sws]

+1

[jkj61]

Thanks for the explanation KYLE

[RMM]

I was under the impression you get the moisture when you compress the air so does putting the filter on the intake really help?

       1st you need to understand Relative Humidity and how water vapor behaves. All air has some water vapor in it. (even the compressed air you buy) RH is the amount of water vapor in the air relative to the max it could hold at it's temperature and pressure. So 50% RH tells you the air contains half the amount it could hold. 100% is saturated air and it can't hold any more. When you take air and compress it to 100% the air will be at the Dew Point. DP is the point that water vapor will/must condense into liquid. Every cloud in the sky is at this point. So when it happens in a vessel like a tank....condensation must occur. Water always condenses on something. In the clouds it condenses on particles of dust, smoke and pollen.  In a tank...it condenses on the tank.   
        When you run air thru the compressor.....it is the first water removal for the air. Then when you take that air which has a lot less water in it and run it thru desiccant crystals, they remove even more of the water from that air.
       If the pump then takes that air and compresses it to the dew point more water will condense in the pump and when you depressurize the pump to remove it from the gun, you will see water exhausted from the pump. Using my boosting method I never see water come from my pump or see grey grease that has water in it. That tells me that the air I am moving into the gun is not at the dew point and therefore is very dry.
       Once air is in the gun and you lower the pressure by shooting the gun, the RH of the air in the gun will do nothing but go down with each shot as you depressurize the reservoir on the gun. So long as the RH is low enough that liquid water is not condensed on the metal, no corrosion can be formed.
       I hope this has not been too scientific for understanding. I've only been a scientist for over 40 years.

I thank you, Sandspike, sir and with sharing your knowledge generously I've accrued more knowledge.  What would be your professional opinion, with most not understanding your explanation, in using desiccant before compression, or in general is it worth the money and effort?

 

I did 10 and or 20 psi boosting on the above pictured Benjamin setup but not tried it with my mechanized Benjamin.  I might have to give it a whirl..   

[Sandspike]

I wasn't entirely complete on my setup. Here is my airflow:
Outside air(14.7psi@sea level)>compressor @ 150spi>desiccant filter/regulator@25psi>desiccant filter on Benji pump>gun.
IMHO the first compression to 150psiby a compressor is very important as it removes a great deal of the moisture from the air. Then running that air thru desiccants further removes moisture and the desiccant will last much longer if most of the water is removed by a compressor first. Your large home made desiccant filter looks like it should do a great job. When it comes to desiccant....more is better.

Someone ask about acquiring desiccant crystals, Walmart sells it in a rather large container for about 12 bucks.
The desiccant can be dried in an oven and reused many times.