Posted by: Dale "Head_Hunters" DuPont on October 02, 2003 at 19:02:49

": I'm making one of these, so can anyone tell me if it will work? It has about a 3' barrel, 2" diameter, and an 18" expansion chamber, also 2" diameter. The trigger is a ball valve, and behind the trigger is a pressure gauge on a T. The CO2 tank is under the expansion chamber. Everything is Schedule 40 PVC, except for the ball valve, pressure gauge, and the parts that connect to the tank (the valve and a few adapters to connect it to the 3/4" tubing that connects it to the expansion chamber." Got to have a pressure regulator. Period. A Pop Off Safety valve can't vent fast enough to keep pressure from building up unless you get a REALLY BIG HEAVY one... Just cracking open a valve to recharge it straight off of a CO2 or Nitro tank would be a dangerous practice and consequently, you shouldn't / wouldn't pass a field safety check and be allowed to use it. PVC is fragile. Great for a barrel but as a pressure resevior, one gets nervous putting it up next to his head to aim while it is finnishing charging... It is Easy to picture falling down across it and easy to visualize where and how far the various pieces might go that were under pressure.... AND PVC GETS HEAVY REAL QUICK! So I went with the 3 pound, disposable fire extinguisher bodies. Pressure TESTED to 300 pounds. Can handle 150 psi with ease... Free at your local fire extinguisher place. They sell them for scrap aluminum of just dumpster them. Get them WITH the nozzles cause you will NEVER Match the thread. Just cut off the nozzle and drill and tap the inside with a 1/2 Pipe thread and go from there. I used TWO with my set up. 1/2" into a 3/4" T pipe and then to my 3/4" Rainbird Valve. If one goes sour, it has only HALF the pressure charge in it... And you can get LARGER fire extinguisher bodies too. Just make sure the neck is big enough for your required flow rates. Should I break a fitting, MY resevior tanks are in a back pack on my back. Should sit my rear on the ground if they turn into rocket packs. They should not become projectiles. Aluminum dings and dents when hit. Under pressure it Swells and SPLITS in a line. Much Less likely to generate shrapnel should a failure occur. Ball Valves work but open SLOWLY and don't work that well in low pressure system in the 80-150 psi range. People use them but the range and thus accuracy simply varies a lot depending on how consistently you can open the valve quickly. People have better luck with them in High Pressure systems. The ADVANTAGE of a high pressure system is that the Resevior Chamber can be MUCH Smaller. I would suggest trying a currently certified 4 1/2, 9, 12, or 20 oz CO2 tank as a resevior. Rated for CO2 pressures obviously up to 1800 psi Then your BALL Valve and high pressure fittings would all have to be rated for 1800 psi or the operating pressure you select less than that. Now your Ball Valve starts getting expensive. I dragged an all Steel 30 pound RPG around for a morning at D Day two years ago. It STOPPED fun in about a half hour... Got a good workout chasing tanks around and walking back and forth to the reinsertion point with it. I vowed to come back with a very much LIGHTER RPG and did. Got 6 tank kills. Killed once by the FAMOUS Julius out of Chicago which I have since AVENGED at Smakzone two weeks ago at their Fire Fall Scenerio... We are 1 and 1. No, not quite, I disabled his tank with a grenade two years ago. This year I played with a 12 pounder RPG. 9 pounds were in the back pack (contains Full 20 oz CO2, reseviors tanks, Rainbird, Pressure Regulator, Pop Off Safety Valve and plumbing. The other 3 pounds are in the hoses attached to my flow-though pistol grip into a 30 inch barrel. The grip also contains the pressure guage so I can tell at a glance when I have a full charge or am running out of air. The AIR supply hose is 1" ID reinforce hose. Used in plumbing Jacuzzis and Hot Tubs. Got mine free dumpster diving otherwise a 3/4" ID would have been fine and more flexible... Didn't tighten the threads on the hose barb fittings. Left them loose on purpose so they can swivel on both ends of the hose. 3 pounds and 36" overall is Very handy to haul, point, and shoot with. Got a sling for my marker and just hang the RPG by the hose around my neck when I'm not using it. For safety's sake, I decided to start with a low pressure system maxing out at 150 psi. (Rainbird's Max Operating Pressure) I also decided to NOT run around a paintball field with my RPG charged and pressurized. Only when I have a target in sight will I pressurize it. Only takes a few seconds and is charged before I get it loaded and in firing position. The only thing besides the supply tank that is pressurized is the pressure regulator and the 1/8" vinyl hose duct taped to the 1" hose going to my trigger valve in the grip. The off/on is between the tank and the pressure regulator. An old Remote ASA housing. A on / off pneumatic toggle switch is about $10. I got a 5 ported , 4 way toggle for $15. It combined the charging and the firing into one switch in my grip. Pull the trigger it fires and stay in the backward position. ONLY when I push it back forward will it repressurize for the next shot. Literally at the touch of a finger in my trigger grip. Very handy. I used a Rain Bird Sprinkler Valve and decided to elimate the electrical solenoid and go with an all pneumatic triggering and charging system. I have since played with it in drizzling rain or just plain RAINing twice. Very glad I went pneumatic rather than electric. I have some pictures posted at: http://community.webshots.com/user/rpglaw for the Rainbird modification. Plan to post more details and pictures but just too busy playing paintball right now... Battle of the Bulge this weekend. Going to get me some Tiger Tanks at Bastogne. Before I went with the back pack/fire extinguisher tanks idea, I had the traditional RPG with the barrel, valve, resevior all in a line with an air supply tank attached via a remote hose. For a trigger I used a pneumatic air hose sprayer ($7) fitting hooked directly into the Rainbird where the solenoid was removed. Worked great. Opened quick. Might look into that instead of a ball valve. Has high flow and is a lever or push button design. We would be happy to help you get one built... Just post here or e mail me.

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A Pop Off Safety valve can't vent fast enough to keep pressure from building up unless you get a REALLY BIG HEAVY one... : Just cracking open a valve to recharge it straight off of a CO2 or Nitro tank would be a dangerous practice and consequently, you shouldn't / wouldn't pass a field safety check and be allowed to use it. : PVC is fragile. Great for a barrel but as a pressure resevior, one gets nervous putting it up next to his head to aim while it is finnishing charging... : It is Easy to picture falling down across it and easy to visualize where and how far the various pieces might go that were under pressure.... AND PVC GETS HEAVY REAL QUICK! : So I went with the 3 pound, disposable fire extinguisher bodies. Pressure TESTED to 300 pounds. Can handle 150 psi with ease... Free at your local fire extinguisher place. They sell them for scrap aluminum of just dumpster them. : Get them WITH the nozzles cause you will NEVER Match the thread. Just cut off the nozzle and drill and tap the inside with a 1/2 Pipe thread and go from there. I used TWO with my set up. 1/2" into a 3/4" T pipe and then to my 3/4" Rainbird Valve. If one goes sour, it has only HALF the pressure charge in it... : And you can get LARGER fire extinguisher bodies too. Just make sure the neck is big enough for your required flow rates. : Should I break a fitting, MY resevior tanks are in a back pack on my back. Should sit my rear on the ground if they turn into rocket packs. They should not become projectiles. Aluminum dings and dents when hit. Under pressure it Swells and SPLITS in a line. Much Less likely to generate shrapnel should a failure occur. : Ball Valves work but open SLOWLY and don't work that well in low pressure system in the 80-150 psi range. People use them but the range and thus accuracy simply varies a lot depending on how consistently you can open the valve quickly. : People have better luck with them in High Pressure systems. The ADVANTAGE of a high pressure system is that the Resevior Chamber can be MUCH Smaller. I would suggest trying a currently certified 4 1/2, 9, 12, or 20 oz CO2 tank as a resevior. Rated for CO2 pressures obviously up to 1800 psi : Then your BALL Valve and high pressure fittings would all have to be rated for 1800 psi or the operating pressure you select less than that. Now your Ball Valve starts getting expensive. : I dragged an all Steel 30 pound RPG around for a morning at D Day two years ago. It STOPPED fun in about a half hour... Got a good workout chasing tanks around and walking back and forth to the reinsertion point with it. I vowed to come back with a very much LIGHTER RPG and did. Got 6 tank kills. Killed once by the FAMOUS Julius out of Chicago which I have since AVENGED at Smakzone two weeks ago at their Fire Fall Scenerio... We are 1 and 1. No, not quite, I disabled his tank with a grenade two years ago. : This year I played with a 12 pounder RPG. 9 pounds were in the back pack (contains Full 20 oz CO2, reseviors tanks, Rainbird, Pressure Regulator, Pop Off Safety Valve and plumbing. The other 3 pounds are in the hoses attached to my flow-though pistol grip into a 30 inch barrel. The grip also contains the pressure guage so I can tell at a glance when I have a full charge or am running out of air. The AIR supply hose is 1" ID reinforce hose. Used in plumbing Jacuzzis and Hot Tubs. Got mine free dumpster diving otherwise a 3/4" ID would have been fine and more flexible... Didn't tighten the threads on the hose barb fittings. Left them loose on purpose so they can swivel on both ends of the hose. : 3 pounds and 36" overall is Very handy to haul, point, and shoot with. Got a sling for my marker and just hang the RPG by the hose around my neck when I'm not using it. : For safety's sake, I decided to start with a low pressure system maxing out at 150 psi. (Rainbird's Max Operating Pressure) : I also decided to NOT run around a paintball field with my RPG charged and pressurized. Only when I have a target in sight will I pressurize it. Only takes a few seconds and is charged before I get it loaded and in firing position. : The only thing besides the supply tank that is pressurized is the pressure regulator and the 1/8" vinyl hose duct taped to the 1" hose going to my trigger valve in the grip. The off/on is between the tank and the pressure regulator. An old Remote ASA housing. : A on / off pneumatic toggle switch is about $10. I got a 5 ported , 4 way toggle for $15. It combined the charging and the firing into one switch in my grip. : Pull the trigger it fires and stay in the backward position. ONLY when I push it back forward will it repressurize for the next shot. Literally at the touch of a finger in my trigger grip. Very handy. : I used a Rain Bird Sprinkler Valve and decided to elimate the electrical solenoid and go with an all pneumatic triggering and charging system. I have since played with it in drizzling rain or just plain RAINing twice. Very glad I went pneumatic rather than electric. I have some pictures posted at: : http://community.webshots.com/user/rpglaw : for the Rainbird modification. Plan to post more details and pictures but just too busy playing paintball right now... Battle of the Bulge this weekend. Going to get me some Tiger Tanks at Bastogne. : Before I went with the back pack/fire extinguisher tanks idea, I had the traditional RPG with the barrel, valve, resevior all in a line with an air supply tank attached via a remote hose. For a trigger I used a pneumatic air hose sprayer ($7) fitting hooked directly into the Rainbird where the solenoid was removed. Worked great. Opened quick. Might look into that instead of a ball valve. Has high flow and is a lever or push button design. : We would be happy to help you get one built... Just post here or e mail me. [ Follow Ups ] [ Post Followup ] [ WARPIG Tank Talk ]