Page 2 of 5

Posted: Sun Jun 25, 2006 9:14 pm
by djt
im not sure. it would have to be tested. but i have seen some little chunks in water in a 2 liter make it explode, which is around 170 psi, and this metal thing will be smaller and more dry ice possibly.

edit: true professor amadeus it might be hard to find. i bet there has to be some kind of valve that can handle that for industrial purposes. can a brass ball valve? cause you could always just attach the little tank to the big one like a propane injection system.

Posted: Sun Jun 25, 2006 9:19 pm
by D-Roc
You're going to have to find out how much CO2 a 1in. block of dry ice releases first.

Build a small tank, put a pressure gauge in it, and throw in a measured piece of dry ice. Then see how much PSI that piece of ice releases.

Posted: Sun Jun 25, 2006 9:41 pm
by djt
yep thats how it has to be done cause i cant find any facts on how much gas dry ice releases.

Posted: Sun Jun 25, 2006 9:56 pm
by carlbelcher
The pressure that co2 liquefies at varies depending on the temperature but it’s normally around 850psi but I've seen it as high as 1000psi. I use hydraulic fittings on my robot's pneumatic system that are rated to at least 1500psi for safety.

Check out this hydraulic valve:

Image

It's rated to 3000psi and it has SAE 16 ports which are about 1" if you adapt them to NPT. But it's kind of pricey $89.95.

http://www.surpluscenter.com/item.asp?U ... =hydraulic

Posted: Mon Jun 26, 2006 2:14 am
by )DEMON(
A ball or butterfly valve will work, the heavy duty ones.

Posted: Mon Jun 26, 2006 4:47 am
by CS
carlbelcher, your forgetting that it will freeze the valve open and dump the ~850-1000 PSI you talk of into the chamber grenading it. Nice try, but try again...

Posted: Mon Jun 26, 2006 4:51 am
by carlbelcher
No, that valve works great with co2. In fact I've been using it for over three years on my robot with NO problems. Even liquid co2 strait out of the tank will not freeze it open.


EDIT:

I was also thinking more as a main valve for a full co2 pressure steel cannon.

For a main tank valve any hydraulic valve should work here is a 1/4" rated to 5000psi.

Image

http://www.surpluscenter.com/item.asp?U ... =hydraulic

Posted: Mon Jun 26, 2006 5:56 am
by )DEMON(
Robot?

Posted: Mon Jun 26, 2006 6:42 am
by Mihlrad
em... for all the hassle of getting the dry ice machine, getting the dry ice, getting and cutting the pipe and drilling it for a shrader making sure it doesnt leak, etc etc, going to be way more work then just buying the cartridges? I mean i understand where you are coming from but to do all that work, and who knows what a dry ice machine cost to rent, it may be less costly in the long run, but how many do you possibly need?

Posted: Mon Jun 26, 2006 9:42 am
by )DEMON(
Wheres the challange in that?

Posted: Mon Jun 26, 2006 10:25 am
by Mihlrad
... lol.... well with the idea of making them, my wallet personally cant stand up to the challenge.

Posted: Mon Jun 26, 2006 2:49 pm
by )DEMON(
I found this link, http://www.wittemann.com/gen.htm and thought it might be interesting to some people,it explains a bit about C02 production. You can buy your own system but no dought it will be expensive.

Posted: Mon Jun 26, 2006 6:48 pm
by beebs111
he he, steel piston, now thats a concept :D

Posted: Mon Jun 26, 2006 9:46 pm
by carlbelcher
)DEMON( wrote:Robot?
Ya, Apocalypse my 340lb combat robot, I've been testing a full co2 pressure pneumatic flipper system. It uses that valve to fire a hydraulic cylinder with co2 pressure.

Image

Posted: Mon Jun 26, 2006 11:13 pm
by Shrimphead
What are the dimensions on that robot? 340 lbs! Seems a little unlikely to me.