SpudFiles

Here where I live the most common type of plastic pipe is PP (polypropylene) sch 14, 50mm I.D (about 2") with wall thickness of 2mm. (thats 50% of sch 40 pipe wall thickness i think). I use this pipe for chamber of my pneumatic gun. The bad thing about PP is that you cannot glue it since it's very chemical-resistant so I screw it together instead with some plastic glue to make it tighter. My barell is 1" and so far I have only fired some shampoo bottles that fit tightly.


The black stuff is strong tape wound in two layers around the chamber to make it stronger. So my question is how much pressure can this pipe hold? I have called the company that makes these pipes and they couldnt tell me right away (!! man bad service), so I'll have to wait till monday untill I can call them again. I have successfully gotten it up to 60psi. It becomes realy hard to pump to any higher pressure.

Please dont act as if you really dont think you can predict are responces. This pipe is more then 50% thinner then recommended pipe, what you think we are gonna say?

I also dont see tape doing shit in the event of a explosion. If the force is great enough to rupture solid plastic walls, what do you think its going to do to paper thin tape?

Unless you operate at a low pressure around 50 psi, dont think youll have a problem (you specifyed you went to 60). I dont know your situation, but if there wasnt sch 40 avialable you should have just bought metal pipeing.

Ok then...I guess I'll just have to hide behind a wall and see if it will reach 100psi

lol, and when that doesnt work.

Then I'll go buy some copper pipes

Well, checked on harvel.com, and found that PVC sdr 13.5 has a pressure rating of 315 psi.
The tensile strength of PP is 5,000 PSI, and PVC is 7,300 PSI.
Thus the pressure rating of sdr 14 PP pipe should be about 5000/7300*315 or ~210 psi.

I'm more suspicious of the bolts, though... you may want to increase the number of them.

And I can vouch for the resistance to adhesives of PP - I typicaly mix my epoxy in a yogurt lid, and it comes right off afterwards.