# PVC cylinders



## bfjou812 (Aug 15, 2008)

I was reading through the pneumatics section and was amazed at the amount of people that want to make their own cylinders out of PVC. I can tell you from personal experience that WHEN the PVC explodes under pressure that it will hurt you . I was lucky enough not to lose the little finger on my right hand due to this. The PVC pipe was under 30 P.S.I. when it exploded, it cut the tendons, muscle, and nerve in the little finger of my right hand, it almost cut it all the way off. So I would like to say that under no circumstances should you use PVC for anything that has to do with air pressure. It is just not worth it.


----------



## dynoflyer (Oct 8, 2006)

Thanks for the warning, bfjou812. 

Maybe this message should be a sticky under pneumatics.


----------



## The_Caretaker (Mar 6, 2007)

If you had pictures that would really drive the point home


----------



## Lotus (Nov 12, 2004)

This is really important for all of us to not use pvc as an air ram


----------



## Gory Corey (Nov 17, 2006)

Been espousing the detriments of using PVC for pneumatics for years, thank you for echoing he importance of not using this unsafe material for air effects.

I fortunately did not get injured, but had a test vessel designed for 240 PSI liquid pressure explode at 45 PSI of air pressure. Scared the crap right out of me. Drove pieces of clear PVC through 2" of oak, shattered windows, left shrapnel in plaster, terra-cotta, brick and STEEL.

Imagine if a PCV effect failed when you have guests!, if they are injured be assured you you will lose everything, regardless if you are insured.


----------



## Liam (Mar 23, 2007)

Another point that scares the hell out of me about PVC is this. If a PVC device were to shatter and send pieces into your body, the only way to extract them is for the surgeon/doctor to go digging around. Since it's plastic, it will not show up in an x-ray. Nasty at best.


----------



## Dr Morbius (Sep 21, 2004)

P.V.C.
Potentially
Violent
Cylinders


Gosh I'm so clever...I'm gonna reward myself with a bowl of oatmeal...MMmmmmm..oaty.


----------



## bfjou812 (Aug 15, 2008)

Liam, that is pretty much what happened to me . After they dug all the crap out I was told to wait for about 4- 10 days to do surgery to put everything back together. THAT SUCKED!!!!!!! There was also some other damage done , but not that bad.


----------



## poison (May 12, 2008)

Same goes for using SCREEN DOOR OPENERS FOR CYLINDERS.
Not worth the time it takes to convert it to a working cylinder and NOT SAFE!


----------



## bfjou812 (Aug 15, 2008)

Well if you get right down to it using washing machine valves, sprinkler valves ,etc. anything that is not designed for a pnuematic application is not really a wise way to go. Sure it is cheaper, but what is the cost of being safe? I'm not trying to preach, just sharing an experience that I had with PVC so hopefully no one would have it happen t othem.


----------



## rottincorps (Jun 1, 2008)

I worked for a PVC manufacture SPEARS,I was in the destruction department "a bitch en place I might say" I tested valves and believe me when I say when that stuff lets go..............DAM! I'm glad there's a blast shield. DON'T MESS WITH THIS STUFF it aways wins!


----------



## SpookySteve (Jul 30, 2008)

Very true. I built an air powered water cannon for the 4th of July and had a 2" 90º let go on me. Luckly it was in testing and not when I was right next to it.


----------



## scooter133 (Aug 21, 2008)

So what is an alternative to the 2" PVC that is typically used for Air Cannons?


Thanks,


----------



## SpookySteve (Jul 30, 2008)

I would go with galvanized metal pipe. It is a lot more expencive but it is rated to over 3000 psi. 
Now my application involved an incompressable fluid being forced to make a 180º turn which could of contributed to the pipe failure.


----------



## scooter133 (Aug 21, 2008)

So can someone point me to an article explaining the Physics/mechanics behind the reason that it would explode under air pressure vs water pressure?

I know in my yard that I have Air compressed up to 60 PSI at the end of long runs of irrigation PVC that is not been fitted with a faucet yet. 

Does it have to do with the rapid release of the air?

I found some 5 Gallon Air Tanks at Harbor Freight for $20

Thanks,


----------



## bfjou812 (Aug 15, 2008)

SpookySteve said:


> I would go with galvanized metal pipe. It is a lot more expencive but it is rated to over 3000 psi.
> Now my application involved an incompressable fluid being forced to make a 180º turn which could of contributed to the pipe failure.


Galvanized pipe does not add to the amount of pressure a certian diameter of pipe can withstand. Usually the process of galvanizing is done to prevent rusting of the pipe. The "schedule" number of the pipe determines the amount of pressure it can hold or withstand. Schedule 40 is a regular pipe, schedule 80 is a pipe with a thicker wall thickness. Wall thickness is the thickness of the pipe, not the diameter.


----------

