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SCH40 PVC
Posted: Mon Jan 12, 2009 4:21 pm
by Moonbogg
I was reading about pvc burst pressure requirements and 4" sch40 has a min. burst pressure requirement of 710PSI. Why don't people use it for 2-3x hybrids? Or do they...
Posted: Mon Jan 12, 2009 4:25 pm
by jonnyboy
I imagine somebody has. It's not very safe though becuase your approaching the burst pressure not the rating.
The shock wave that comes from the combustion isn't good for pvc as well. I think all the pvc hybrids on this site are sch80. Some of them have even failed but I don't know what mixes they were using. What if you had a ddt?
Posted: Mon Jan 12, 2009 8:04 pm
by Fnord
Jonny basically said this in his post, but PVC is brittle. Hybrids produce extreme shock loads. Combine the two and you'll eventually have a failure.
Noname once had a sch80 hybrid fail with just a 2x mix, and that basically spelled the end for pvc.
Posted: Tue Jan 13, 2009 7:47 am
by psycix
Indeed. Instead of bursting due to pressure, they simply crack up due to the shock loads.
PVC cant handle that and combined with the high pressure, the gun fails catastrophically.
All PVC hybrids will eventually fail. Every shot makes them one step closer to bursting into pieces.
Posted: Tue Jan 13, 2009 8:01 am
by frankrede
psycix wrote:Indeed. Instead of bursting due to pressure, they simply crack up due to the shock loads.
PVC cant handle that and combined with the high pressure, the gun fails catastrophically.
All PVC hybrids will eventually fail. Every shot makes them one step closer to bursting into pieces.
With that mindset, all pvc cannons will eventually fail.
Posted: Tue Jan 13, 2009 1:13 pm
by Moonbogg
wow. I hope aluminum doesn't weaken from shock loads. It shouldn't since they use it in bikes and stuff like that.
Posted: Tue Jan 13, 2009 1:59 pm
by psycix
With that mindset, all pvc cannons will eventually fail.
When subjected to shock loads, yes.
But on simple combustions the shock load is so low that even DWV can be used, though sometimes a cap pops off...
Advanced combustions with DWV pipe are even less safe and even when built from rated pipe, eventually, they will fail.
Though on a normal 1x mix it takes more shots then you would probably fire with that gun.
wow. I hope aluminum doesn't weaken from shock loads. It shouldn't since they use it in bikes and stuff like that.
Aluminum is WAY stronger then PVC. I think aluminum is a very good material because of its high strength compared to its weight.