explosion

A place for general potato gun questions and discussions.
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)DEMON(
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Fri Apr 14, 2006 2:54 pm

i have been on this forum for about a month and am perfecting my pnumatic(its taking a while,im a perfectionist) i have taken my chamber up to 20 psi, 35 is max on my pressure gauge(it will probley do 100+), what would happen if it exploded and what would be the best way to pressurise it with no threat.

i dont want to die at 15 :!:
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beebs111
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Fri Apr 14, 2006 3:21 pm

if it exploded it would send pvc shards flying. :) dont worry about that though, as long as your fittings and pipe are nsf-pw its safe past 100 psi if there dwv itll be safe to 50 max
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Rambo
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Fri Apr 14, 2006 3:26 pm

I think that the coke bottles are safer then PVC.They can go more then 120 and it they blow there won't be much shrapnels.Ant the are very cheap.
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beebs111
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Fri Apr 14, 2006 3:36 pm

yeah but the bottles arent pressure rated, so there is no gaurentuee cuz theyre not manufactured for pressure
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Andrew52
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Fri Apr 14, 2006 3:36 pm

yes but i think they have a short fatigue life and if its just a little shratnell would still f u up and there not very sturdy
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boilingleadbath
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Fri Apr 14, 2006 3:39 pm

I'v never heard of a acctual pipe failure with pressure rated pipe.
Normaly what happens is that somebody solvent welds incorrectly, causing the joint to be weak. Thus it tends to fail by un-gluing the fittings and accelerating them backwards at high rates of speed.

...so you'll be safe so long as you don't stand behind it. (or in front of it, silly)
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Shrimphead
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Fri Apr 14, 2006 4:51 pm

Pressure rated pipe is rated to waaaayyyyyyy more than 120 (unless its 8in!). But blb, didn't somebody have a detonation in their pressure rated hybrid? But that's not pneumatic and made pressures way out of the normal spectrum that the pipe can't withstand.
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Atlantis
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Fri Apr 14, 2006 7:29 pm

Normal PVC is rated for up to 330 PSI, WATER! This means it can only hold a MAX of 160 PSI with air. Most people keep it under 120 for safety. Also, pop bottles have been rated for 160 air PSI. There are a few cannons on here that use pop bottles. Example...
http://www.spudfiles.com/forums/download.php?id=905&
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rna_duelers
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Fri Apr 14, 2006 10:54 pm

I use the coke bottles for pneumatic chambers and they hold up fine i use the 600ML bottles and they have a very long life span i have one that is about 6 months and still going good and i air it up to 120psi nearly everytime off my air compressor,and when they do blow they rip they dont shrapnel well when i did have one explode it was a 2Letre bottle it just ripped it was still very loud but it didnt fly apart into shards.but i dont push my bottles past 120psi my friend actualy explodes them for fun they get to about 150-160 and then they go boom but no shrapel.
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boilingleadbath
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Fri Apr 14, 2006 11:12 pm

Shrimphead: Oh, yeah, I forgot about that... though I don't remember who it happened to or the consequences.

But, as you stated, a detonation isn't really normal use - the pressure in the shockwave is really high and has been known to cause <i> steel</i> pipe to bulge out.

Atlantis: please refrain from pulling shite out of your butt.

There is no such thing as "normal PVC":
In much Europe, and possibly australia (I'm not going to check) they use a lettered system. There are many different ratings, and the acctual pressure handled by the pipe may vary depending on diameter, even for the same letter (again, didn't check).
In the US, the primary system is schedule. Pressure rating varies with size across the same schedule number.
Also in the US, there is the SDR system, in which pressure rating does not vary with diamter... but there is no class 330 pipe.

The burst pressure of the pipe does not vary with the contained fluid - 330 water means 330 air. (although the pipe will fail in a more energetic manner with air, which is why PVC pipe isn't rated for gas pressure)

The burst pressure =! the rated pressure... acctualy, there's a saftey factor of about 4-6 built in to those ratings.
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Rambo
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Fri Apr 14, 2006 11:41 pm

When they say the presure rating, it means tha this is for many erars of use in hostile invirement.And my coke bottle hybrid works fine with 4x the mix.I discovered that the coke bottles are bad for auto combustions.They begin to melt after few shots.
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)DEMON(
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Sat Apr 15, 2006 2:55 am

thanks for that i think il test it properly now
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Brian the brain
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Sun Apr 16, 2006 12:15 am

If the material bends it won't shatter...that's why coke bottles are safe.The weakest part is it's "belly" and that part folds easily without breaking.BLB...do you concurr??( muhaha)

Fittings coming off now that's a different story
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Oh my friggin god stop being so awesome, that thing is pure kick ass. Most innovative and creative pneumatic that the files have ever come by!

Can't ask for a better compliment!!
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Andrew52
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Sun Apr 16, 2006 12:27 am

yes but its nice to have somthing sturdy like pvc but it would be cool to see the moisture when the rapid pressure drop happens
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