Butterfly Valve- How to Quickly Open

[duwem]

Guess the pumpkin guys use butterfly with large springs or pneumatic cylinders to open them fast. I can’t find pictures of this. Anyone have any or done this?

[Moonbogg]

I found a video of one that uses a cylinder.



I'm thinking just yanking it open might be fine as well. I think it might depend on the size of the cannon? I'm not too sure. I seem to remember reading that you can't hit the pumpkin too hard or it will break. Not sure if that means low overall pressure or gradually expose the pumpkin to pressure and then fully open the valve, but I think that would require a huge cannon to benefit from a variable speed opening valve like that. If I were to build one, I'd research and figure it all out. But I'm not building one, so keep us posted!