How to antisiphon a CO2 Tank

[WILD4WAR]

Originally Written by druid on the MilSimOG, I am just adding it to the MilSimE and it is his info. It is good info and I would like to see it live on after the MilsimOG is no more. Thank you druid for the info.
Why do it? It's better on your marker's internals...O-rings, seals, etc. by keeping the LIQUID Co2 out of the marker as much as possible. This tube draws the gasseous CO2 off the top of the tank while the liquid CO2 lays on the bottom. This will allow you to shoot faster with less chances of freeze-up too. It will work with expansion chambers and CO2-friendly regulators but you may have to increase the input pressure a bit. THIS WILL NOT WORK WELL WITH REMOTE SYSTEMS!!!

First and foremost, I suggest you consult a certified airsmith to perform this mod. The process only costs a few bucks for materails and labor. If you are sure you can handle this, I will not be responsible if something goes wrong.
I'll say it again...This will NOT work with remotes, nor will it work with vertically mounted bottles.
Materials needed:

1 ea Large and small crescent wrench
1 vice
1 brass-bristled brush
1 dental pick
Allen wrench set
White out pen
RED Locktite
candle, torch or heat gun
1/4" copper tubing
WATTS model A-22 (pictured)
part #- PB968-P
1/4" x 1/8"
Tube w/ Insert
MIP Connector
(Home Depot plumbing dept)
or substitute (sugested...it's easier to find)
ANDERSON METALS CORP, INC (AMC)
1/4" compression x 1/8" MIP connector
# 10068-0402
6 days for Locktite curing time.
Sidenote: Locktite only cures in the absence of oxygen. The threadlocker starts to cure from the center of the area covered, out...so if the locktite is on threads that you can see, it will remain a liquid until you remove the O2. You can try to use plastic Ziplok bags and a match to burn away the O2, but I have not tried this.
1. make sure the tank is EMPTY by pushing in the valve pin with your fingernail.
2. remove the O-ring and burst disc from the tank.
3. screw the tank into the asa.
take your white out pen


and mark the top of the bottle neck AND VALVE, directly under the center of the grip, remove from the marker


tightly mount the tank into a padded vice but don't crush the bottle. Heat the bottle neck and valve to about 200* for about 5 mins to degrade the thread locker. Turn valve out with large crescent wrench.


Valve is removed. Take the wire brush and pick and clean off all the threads. You will notice a hole in the large threaded area. pick it clean...it needs to be UNOBSTRUCTED. ( YOU'LL SEE A PIC LATER OF THE CLEANED HOLE.)


Look at the bottom of the valve. There's a hex plug that needs to be removed. CAUTION: there's a spring in there. remove it slowly. Inspect the spring and the valve pin and seal, make sure they are clean and undamaged. Replace the pin seal now if it's damaged.

[img][http://www.milsimzone.com/uploads/11...19786.jpg/img]

Take the WATTS fitting apart. There are 3 main pieces...a nut, a 'flaring tool' and the threaded fitting itself. Feed the nut onto the end of the copper tubing like this
[img][http://www.milsimzone.com/uploads/1184503977/gallery_4899_333_22417.jpg[/img]
and insert the flaring tool into the tubing ALL THE WAY. Leave it there


FOR THE RECOMMENDED SUBSTITUTE FITTING: Insert end of tubing into nut, Slide the compression ring onto the tubing as well. Continue as stated below...short threaded end of fitting, etc.
Note this SHORT threaded end...thread it into the nut one turn and STOP



Take the RED locktite and add it to the threads of the SHORT end and tighten it together. DO NOT STRIP THE BRASS THREADS!





Thread this into the back of the valve body one turn and STOP. Add RED Locktite to the threads and turn in completely. When tight, check to see that the valve pin works properly by pressing it in with your thumbnail

HERE'S THE PIC OF THE CLEANED OUT HOLE. This is an emergency blow-out hole. IF, for some reason, the valve unscrewed from the tank and not your marker, the gas will be released out this hole. This is why it must remain UNOBSTRUCTED.


SET THIS ASIDE FOR 72 HORS SO THE LOCKTITE CAN PROPERLY CURE
Next, remember that mark you placed on the valve?

bend the tube in a nice arc so that the end of the tube arches up to that mark. Make sure there are no kinks in the tube.


Check the end of the tube to make sure it is clear and debris free.


Place Locktite on this section of the threads and thread into the bottle. The end of the tube should not touch the inside of the bottle


Thread the valve into the bottle until it is seated all the way and that the marks on the valve and bottle neck line up. SET THIS ASIDE FOR ANOTHER 72 HOURS.
after this time has passed, replace the burst disc and bottle O-ring and get it filled. When placing on the marker, those white marks should ALWAYS be on top of the tank