#1
Posted 02 April 2008 - 07:06 PM
Also, could I use PVC and a solenoid to make a Super Soaker?
#2
Posted 02 April 2008 - 07:08 PM
#3
Posted 02 April 2008 - 07:16 PM
#5
Posted 02 April 2008 - 07:31 PM
pvc is made for over 100 psi for water... what labels are you reading?Well, I understand that, but PVC is meant for water's 100 PSI, not air pressure.
#6
Posted 02 April 2008 - 07:35 PM
#7
Posted 02 April 2008 - 07:49 PM
Edited by veginator, 02 April 2008 - 07:50 PM.
#8
Posted 02 April 2008 - 07:52 PM
I'd prefer not to have plastic in my fucking body, prick.
#9
Posted 02 April 2008 - 08:00 PM
#10
Posted 02 April 2008 - 08:11 PM
What kind of pressures do you plan on using in this gun anyway. 40? 50?
He hasn't decided yet, as it says in the first post.
If it is "pounds per square inch", then PSI with air should be the same as with water.*
*Disclamer: I don't this for a fact, but it makes sense.
#11
Posted 02 April 2008 - 08:13 PM
First off, read the post referenced above by Carbon.
The pressure is the same for both water and air. Pressure refers to how much force per unit area is applied. Pressure is just a measured quantity. 50 PSI air pressure is the same pressure as 50 PSI water pressure. The problem is that gases expand much more than liquids, so when PVC fails under gas pressure it explodes. When PVC fails under liquid pressure, it cracks and leaks, maybe somewhat violently, but it doesn't explode.
I've seen a video of a PVC tanks exploding from being compressed too much air, but the gun took a hatchet to the tank at first so it wasn't even realistic.
Use reasonable pressure, don't damage the pipe, and use general common sense and you have nothing to worry about.
#12
Posted 02 April 2008 - 08:15 PM
Fact: 100 PSI is 100 PSI. It doesn't matter if it's liquid or gas.
The major difference between 100 PSI of air and 100 psi of water is the potential energy (I'm using that term loosely so don't flame me). When water is compressed to 100 PSI, there isn't very much change in its volume. That means when the pressure is released, it's not expanding much. If it's not expanding much, it can't propel anything very far. Air, however, when compressed to 100 PSI has had a dramatic decrease in volume. When the pressure is released it's going to rapidly increase in volume and can therefore propel things very far and fast. So if PVC was overpressurized with water, the resulting bursting of the pipe wouldn't be much more than spewing water. The PVC wouldn't be propelled very far (likely not at all, just crack). If PVC is overpressurized with air, the resulting pipe burst could send PVC shrapnel very far and fast.
However, 60 PSI (probably the max you'll need for any gun), isn't enough to do anything. If it were very cold and you took a hammer to it, yeah you might have problems, but nothing lethal. There is virtually no danger with using 60 PSI with PVC.
#13
Posted 02 April 2008 - 08:19 PM
Which weighs more, a pound of bricks or a pound of feathers?I'm using it for air. And normal air has 9/10 more pressure than water. Gas's atoms are always moving, and liquids are lazy, they just go with the flow. When there is more pressure with the wild energy, the gas is constantly moving, and any sudden bump can make it explode.
Which was more pressure, one pound per square inch of air or one pound per square inch of water?
And veginator, From http://internettrash...epage/spud.html
--Compressed air is not safe like compressed water!!!--
-- Why? Water doesn't compress much, but at 100PSI, air is compressed into about 1/7th its original volume, which means that if the pipe cracks, your gun has become a bomb. There'll be shrapnel which can literally blow your arm off (hey, I said it was manly). PSI means pounds per square inch.. picture 100lb weights pressing outwards on every single square inch of your gun's air chamber. Respect it! Here's a sobering excerpt from some email I recieved:
"As a PVC fittings manufacturer your contraption scares the hell out me... It is right up there with some of the most dangerous things anyone could do. If you had ever seen the damage that could occur to your body if it ever did explode you would never build it out of PVC...
I have personally come into contact with people who have not heeded the warning, it is not a cool sight."
Edited by Qui'lan Fett, 02 April 2008 - 08:22 PM.
This guy can see the future!
hasbro in a nerf war!!!!! dude the will cancel it and confinscate are guns
#14
Posted 02 April 2008 - 08:41 PM
The reason to never go above 100ps with SCH40 or SCH80 products (which are rated for 300-600psi of water pressure) is because 100psi of gas will not be stressing the pipe significantly. So external shock is not likely to result in an explosion unless you specifically are intending to puncture it somehow. In which case you probably deserve to die.
Any gas pressure level is going to be equivalent to water pressure levels. But gas pressure is always more dangerous. While the amount of stored energy is the same, pneumatic pressure can release it at a much higher rate (more violently) than hydraulic pressure can.
Edited by CaptainSlug, 02 April 2008 - 08:43 PM.
#15
Posted 02 April 2008 - 09:13 PM
How is that a reason not to?Here's the bottom line.
The reason to never go above 100ps with SCH40 or SCH80 products (which are rated for 300-600psi of water pressure) is because 100psi of gas will not be stressing the pipe significantly. So external shock is not likely to result in an explosion unless you specifically are intending to puncture it somehow. In which case you probably deserve to die.
This guy can see the future!
hasbro in a nerf war!!!!! dude the will cancel it and confinscate are guns
#16
Posted 02 April 2008 - 09:20 PM
Misconception: Air has more pressure than water.
Fact: 100 PSI is 100 PSI. It doesn't matter if it's liquid or gas.
The major difference between 100 PSI of air and 100 psi of water is the potential energy (I'm using that term loosely so don't flame me). When water is compressed to 100 PSI, there isn't very much change in its volume. That means when the pressure is released, it's not expanding much. If it's not expanding much, it can't propel anything very far. Air, however, when compressed to 100 PSI has had a dramatic decrease in volume. When the pressure is released it's going to rapidly increase in volume and can therefore propel things very far and fast. So if PVC was overpressurized with water, the resulting bursting of the pipe wouldn't be much more than spewing water. The PVC wouldn't be propelled very far (likely not at all, just crack). If PVC is overpressurized with air, the resulting pipe burst could send PVC shrapnel very far and fast.
However, 60 PSI (probably the max you'll need for any gun), isn't enough to do anything. If it were very cold and you took a hammer to it, yeah you might have problems, but nothing lethal. There is virtually no danger with using 60 PSI with PVC.
Here's the bottom line.
The reason to never go above 100ps with SCH40 or SCH80 products (which are rated for 300-600psi of water pressure) is because 100psi of gas will not be stressing the pipe significantly. So external shock is not likely to result in an explosion unless you specifically are intending to puncture it somehow. In which case you probably deserve to die.
Any gas pressure level is going to be equivalent to water pressure levels. But gas pressure is always more dangerous. While the amount of stored energy is the same, pneumatic pressure can release it at a much higher rate (more violently) than hydraulic pressure can.
You guys hit the nail on the head. The pressure will be the same, but the key word here is COMPRESSIBILITY. You should be fine though, and if you're worried wrap it in duct tape/gorilla tape/more tubing.
#17 Guest_DarkInfection_*
Posted 02 April 2008 - 09:25 PM
Edited by DarkInfection, 23 June 2010 - 09:44 PM.
#18
Posted 02 April 2008 - 10:27 PM
#19
Posted 03 April 2008 - 05:14 PM
If it helps i also use a ball valve, you guys don't know much about pvc. Look at spudfiles.com for some help
#20
Posted 05 April 2008 - 10:11 AM
The issue isn't whether or not PVC or CPVC can handle high pressure. I've read stories of people taking their spudguns and nerf guns up above 100 PSI all the time.Is it sch. 40? I take a 1/2" sch 40 tank up to 130 psi no problem all the time.
If it helps i also use a ball valve, you guys don't know much about pvc. Look at spudfiles.com for some help
The issue here is that PVC, when under high air pressure, fails very poorly. Even though you built something that can handle the pressure, that doesn't take away the fact that you are essentially running around with a bomb in your hands.
So therefore, if you do something wrong like forgetting like glue your gun together:
http://www.spudfiles...ded-t13852.html
You stand a very real risk of hurting yourself or someone else. That was just after one search, and I know for a fact that external stress like dropping or bumping a tank might also cause it to fail. I know that forgetting to glue properly is an obvious mistake, but do you really want to maximize the damage to yourself and others should a mistake happen?
Granted, the explosion that results from a bad failure will be much smaller with low PSI, but bringing the PSI up will only increase the risk, should a failure occur.
#21
Posted 05 April 2008 - 10:17 AM
Most discussion of air tanks aren't talking about skinny PVC. Larger diameters have lower pressure ratings, and thus, lower safe pressures.
#22
Posted 05 April 2008 - 05:15 PM
#23
Posted 05 April 2008 - 05:43 PM
Speaking of 2 inch pvc... Does anyone know the pressure ratings for it? I got a few feet from some construction workers that didn't need it a while back so I've been using it...I'm using 1" PVC if that makes a difference. I want to go up to 2" though.
#24
Posted 05 April 2008 - 06:34 PM
I think it's generally accepted that 100 psi is the absolute upper limit of what you should use for just about any size of sch.40 PVC, really...and if you keep it under 70 it should be no problem at all unless there is some flaw/damage already don to the PVC.
-Jwasko, STILL Sole Surviving member of Steel City Nerf and Sober Sister of the Sex Dwarves
We NERF ON all day, and FUCK OFF all night
#25
Posted 05 April 2008 - 07:08 PM
Next time you have a question like "What's the pressure rating of 2 inch PVC pipe?" try some Google searches. It saves everyone time when you use Google. I'll save you time now and just give you a good link: http://www.harvel.co...ch40-80-dim.asp
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