3 ms·
> This is also the reason why pvc is super dangerous for compressed air. Back in the day all us kids knew to get the ABS stuff when building our potato cannons
by function_seven 3y ago
> This is also the reason why pvc is super dangerous for compressed air.
Back in the day all us kids knew to get the ABS stuff when building our potato cannons. I was terrified of the combustion chamber shattering right next to my face.
- iancmceachern 3y agoWe didn't know this and I'm realizing now were incredibly lucky!
- Infernal 3y agoOh shit - we did not know. I guess we got lucky too!
- macNchz 3y agoI remember hearing the opposite, 20 years ago when I made one–that PVC was preferable to ABS because you couldn’t readily buy ABS with any sort of pressure rating.
- function_seven 3y agoIt didn’t even occur to me that ABS pipe is pretty much only used for drainage and vents. I think it’s still probably decent to have unrated pipe tear smoothly rather than rated pipe—over pressured—shatter? I guess the pro move is to either (1) fully characterize the amount of pressure made from a random shot of hairspray, then choose a PVC pipe to accommodate, or (2) put a larger ABS sleeve over the inner PVC combustion chamber to contain the shrapnel.
- wrycoder 3y agoThat's why you do a pressure test at twice the working pressure, with the thing under a blanket. This should be repeated every year.