[Adama]

Originally Posted by skimoose

This is the most reoccurring issue with air launchers and combustion "guns". PVC is extremely dangerous!!
The PSI rating printed on the pipe is for liquids NOT compressed gases of any sort. The biggest problem with PVC is that its failure, when it occurs, is catastrophic. PVC shatters into numerous sharp shards that can be propelled at dangerous levels. PVC generally will not exhibit signs of fatigue until it explodes. People have also argued that PSI is PSI, so why isn't PVC safe with compressed gas? By the very natural of solids, liquids and gases, gases will release stored energy much faster than a liquid will, even liquids can still dangerous.

As far as your logic of a lot of people using these devices and none being hurt. That is a falsehood perpetuated by the internet. I have seen posting of failures but they are few and far between because most people don't want to post their failures, only their successes, and they certainly wouldn't post if someone was injured (don't you think the lawyers would love to get their hands on that incriminating evidence). Also, in most cases these people use these devices a few times before tiring of them, or getting caught (combustion guns). They've rolled the dice a few times and lucked out. PVC failure is generally from fatigue which means each time you load and unload the pipe you stress it and each time your chances of a failure increase. Load that pipe enough times and it will certainly fail.

I personally know at least four incidents of PVC failures. Luckily, no one was seriously hurt ONLY BECAUSE OF PURE LUCK! In one case, an individual had a charges air launcher under his coat. Luckily it failed away from his body, but it completely shredded a heavy winter jacket being worn. If you saw the jacket, you'd think the person wearing it was DEAD! Pure Luck plain and simple.

Our Dewbot T-shirt air launcher is built with an all metal storage accumulator, piping, and valve system in which every component used was rated at over 150 PSI. Where we used flexible hose (after the solenoid valve) it was rated at over 180 PSI and is reinforced so that a rupture would only cause a tear in the material. The launcher tubes are made out of polycarbonate pipe which is rated at 9000 PSI and was $11/foot. That should give you some idea of how seriously we took safety when using plastic pipe, even polycarbonate.

Don't be misled by what you don't find on the internet.

First of all I have read the entire thread and am well aware of the facts you stated in red text several times before. I wasn't speaking so much as in defense as more of an awarness of a very large community. It was an attempt to bring to light more than what had been discussed already. The internet is and can be very misleading but none the less it is present and full of more empirical data (probably positively biased) and trial and error on the subject than can be completely ignored.

On a side note I have built and operated a combustion gun for several years now. (if you can't make one you probably shouldn't have one ) Its stored inside away from temperature extremes, I do not fire it in extreme cold, I use weak fuel such as hairspray and I always treat it as an actual fire arm. That is why I was probing into combustion guns.