12 gram efficiency Q
 

Do 12 grams work better when feeding the valve liquid or gas? I've noticed that lots of guns (PGPs, dropout equipped nelsons) have the cartridge in such a way that it looks like it would feed liquid rather than gas. Are these actually feeding liquid?

Well, I think that in the liquid state, co2 has more energy. If you put the same amount of volume of c02 in liquid form instead of gas, it will shoot harder and at a higher FPS. If you fill the chamber full of liquid, you use alot of the 12 gram. I think you want it to be gas state.

But, I could be wrong. Im not a wiz on how air and c02 works, so I could be wrong.

Good luck.

Vaporized/ atomized liquid in Nelsons small piercing holes help with the effect. Power tubes and liquid CO2 are not a good mix for longevity.

Sheridan valves want more gas than liquid but remember the valve chamber is twice as small as a Nelson. The gas must also take a 90 deg turn so some liquid is needed to get the best efficiency.

All this science stuff hurts my head... :confused:

Technically, yes, a valve being fed liquid would be more efficient...

ASSUMING it is well controlled, and that all the liquid boils off and then expands most of the way before the ball leaves the barrel.

This is fairly hard to acheive. Most of the time, in a nelson design, the powertube, valve, and peircing pin serve to boil off the co2 well before it reaches the ball. Basically, you wouldnt know if that is happening or not, unless you made a clear gun which would allow you to see the co2 boil off and where it happens. If it happens after the valve, you'd be doing well. before the valve would be a problem.

Valve going on liquid will be more efficient, because liquid CO2 has more energy density, so you will have better air flow with the same tubing and you can shorten and speed-up the valve operation to get the same fps. But short after you deplete some part of liquid CO2 in powerlet, you will have droup out - because you can not use the siphon tube in powerlet, separating the liquid CO2 is very difficult here... the only posible solution will be perhaps the reversed vertical setup, but that is very uncomon :-).

So, shortly, going on liquid with powerlets is best for efficiency only in beginning, with your first shoots, where you can hold the liquid in the valve. But the goal of efficiency tuning is comonly totally different - hold consistent performance at longest... and there is a lot better going on gas CO2... best with "short" vertical setup - powerlet placed in the grip like in case old Nellspot 007 or 3357 Spotmarker where you will have the gas CO2 good separated and you will have on the other side not affected the unintendet expansion in the marker like in case of Phantom VSC for exception.

Best will be go with vertical setup on Low pressure with small in-build reg - you can use a lot more of the gas fill in the powerlet with great consistency, even after is the liquid CO2 depleted. This is imho the way how make the most efficient stock class marker... and Sheridans are imho better for that than nelsons.

Gas

The valve itself is adiiferant story, as technicly, it would work better on liquid, however the co2 would be depleted within 10 shots for a 12 gram.

B has the best answer reguarding stock guns. With a little tinkering you can get the sheridan valve to work better on gas alone, but again as B has stated, you have that 90 degress turn still, even though you can change the length of the radius, and thus make flow better.

Generaly speaking, run 12 grams in the vertical possition.

Best 12g efficiency I've ever gotten from them was in from the horizontal position. Basically speaking... Drop out changers.
I would expect the issue has more to do with Sheridan vs. Nelson valves.
Nelson wins again.

^ Nelson valve chamber is huge when compared to a sheridan, thus the liquid has more time and space to expand into a gas.

There is also the temperature varible, as at 0 degress I can get 10 usable shots out of a factory springed stock nelspot, if I pump easly. I get 8 with factory springs( same gun in fact) but with a horizontal changer. Actualy did this as a test a year ago just for kicks. Also the heat from your hand around the 12 gram/grip will boost the shot count by 1-2 shots vs just pulling the trigger.

Some food for thought :

R744 is CO2

http://www.mcarterbrown.com/gallery/data/500/c02.JPG

Fixed now

Also, heres one thats more painball specific

http://www.warpig.com/paintball/tech...sses/co2pv.gif